Fan Switch Temperature Options

I had posted this question while most of you were at the summit - so this is kinda of a repost .............

The stocker fan switch comes on at about 219 F degrees - when your sitting in traffic, - that seems a little late since the bike will crept up to about 230 F and bounce around 225 - 230. It would be nice to kick that fan on sooner. (I know I could stick a manual switch on it) I'm wonderin what optimum would be?

So just out of curiosity, for 5th and 6th gen, if you could have the perfect fan switch, it would kick on at ______________ degrees F and then shut off at ______________ degrees F, what would your 2 numbers be?


I'm thinking 205 and 190, too low?

MD

205 and 190 sound good to me. being from SC sitting in traffic in 100+ temps, i would love for it to cut on 195. i think it all depends on where you live and how much traffic you deal with.

Mine works fine as is. I think someone (Maybe Seb?) mentioned that because we have digital temp displays we tend to fixate more on the exact on off numbers. I'd agree, my PC800 has an analog gauge and it comes on around the middle area every time! :happy:

205 & 190 seem like good temps; I've noticed that when my bike is over 220, that mid-range hesitation is much more noticeable, sometimes painfully so like slow corners coming away from stoplights. This is another issue that would be cured with a Microsquirt ECU but I'm budget constrained and scared to start that kind of project on my own right now.

Are you taking a poll because you are able to make a re-calibrated switch?

Or are we just making conversation?

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.

[image: View Post]TucsonErik, on Aug 26 2009, 08:38 PM, said:

Are you taking a poll because you are able to make a re-calibrated switch?

Or are we just making conversation?

My background is automotive engineering so I thought well yeah why not dig into gettng a custom batch of switches. Cant give any details as of yet, the supplier may decide he doesnt want to fool with it.

MD

[image: View Post]coderighter, on Aug 26 2009, 09:00 PM, said:

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.

Why not just stick in the VTR Fan?
http://www.vfrdiscussion.com/forum/index.p...mp;#entry640043

MD

um...I'm pretty sure someone already took care of this problem by switching out the fan blades with something else that would pull air from the outside. Think they also put together a little how-to. Just somewhere beyond that search button...

[image: View Post]mello dude, on Aug 26 2009, 08:15 PM, said:

[image: View Post]coderighter, on Aug 26 2009, 09:00 PM, said:

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.

Why not just stick in the VTR Fan?
http://www.vfrdiscussion.com/forum/index.p...mp;#entry640043

MD



I saw that thread. The fact is, the fan pulling air from the cooler side is a better idea when the bike is either not stopped or slow, when a fan is useful. As part of my testing, I installed a remote thermo sensor next to the fan frame. At one point while waiting at a stop light on a 90 degree day, just before the fan kicked on, the temp read 157 degrees. I don't think that pushing 157 degree air through the radiator is going to be real effective. Plus by pushing air, you add the heat of the fan motor, which is quite a bit.

I believe the factory fan setup will do the best job, but it just needs to not run and counter act natural air flow will the bike gets up to speed. When the bike is up to speed, no fan is going to help anyway. The only time I could see a reverse fan would help, would be that short time that you're moving fast enough to remove the hot air in the "tunnel" (15-20 mph), but below 30-40 mph when the fan is not useful anyway.

Plus, leaving the fan standard rotation and turning off when "not needed" should double it's useful life. Also, because the natural air flow is working against the fan when the bike is moving the fan working harder and is actually drawing more current, taxing the alternator and charging system for no reason. This makes the fan motor, alternator, and engine (increased load) hotter. I know small, but it all adds up.


Side note, after I lessen the fan run time, I'm changing the thermo switch to 210 at the next antifreeze change. If I did that now, the fan would run way too much. In city traffic, the fan would actually keep the bike hot.

[image: View Post]coderighter, on Aug 26 2009, 09:00 PM, said:

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.
I have not tried it on a 6th gen fan, but did you try the superhawk fan - 19020-MBB-003 or what ever its superseded to now.
Its designed to move air out not in.
Its all of 29 bucks, and should bolt tight in.

then it doesn't matter if it stays running when the bike is moving.

If not there are other ways you could your stocker get it to push air out efficiently instead of pulling it in.

[image: View Post]coderighter, on Aug 26 2009, 11:28 PM, said:

[image: View Post]mello dude, on Aug 26 2009, 08:15 PM, said:

[image: View Post]coderighter, on Aug 26 2009, 09:00 PM, said:

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.

Why not just stick in the VTR Fan?
http://www.vfrdiscussion.com/forum/index.p...mp;#entry640043

MD

I saw that thread. The fact is, the fan pulling air from the cooler side is a better idea when the bike is either not stopped or slow, when a fan is useful. As part of my testing, I installed a remote thermo sensor next to the fan frame. At one point while waiting at a stop light on a 90 degree day, just before the fan kicked on, the temp read 157 degrees. I don't think that pushing 157 degree air through the radiator is going to be real effective. Plus by pushing air, you add the heat of the fan motor, which is quite a bit.

I believe the factory fan setup will do the best job, but it just needs to not run and counter act natural air flow will the bike gets up to speed. When the bike is up to speed, no fan is going to help anyway. The only time I could see a reverse fan would help, would be that short time that you're moving fast enough to remove the hot air in the "tunnel" (15-20 mph), but below 30-40 mph when the fan is not useful anyway.

Plus, leaving the fan standard rotation and turning off when "not needed" should double it's useful life. Also, because the natural air flow is working against the fan when the bike is moving the fan working harder and is actually drawing more current, taxing the alternator and charging system for no reason. This makes the fan motor, alternator, and engine (increased load) hotter. I know small, but it all adds up.


Side note, after I lessen the fan run time, I'm changing the thermo switch to 210 at the next antifreeze change. If I did that now, the fan would run way too much. In city traffic, the fan would actually keep the bike hot.

well I did not see that before my last post, and I did not do any serious research like you did, but I can tell you this.
the VTR fan works, before I added it my 01 would get way up into the 230+ range and stay there pretty much as along as the fan was on.
So even if the area near the frame was 157 degrees before the fan kicks on, its still cooler than the 230+ that the rad's are going to climb to.

Besides once you get the air moving out, the bike is not going to be heating that airspace to 157.

The reality is that with the new fan blade from the vtr, the fan comes on at 224 and the temperature drops, not rises like before, Drops. It runs in cycles like it is supposed to instead of coming on and just staying on until you get back up roughly 35 mph. To me its obvious that it works.


As a plus anytime the fan is running and the bike gets moving the fan first freewheels, then begins generating its own power (like a mobil wind turbine).
It's not efficient at this, but it has to reduce the load.

[image: View Post]JES_VFR, on Aug 27 2009, 12:19 PM, said:

[image: View Post]coderighter, on Aug 26 2009, 11:28 PM, said:

[image: View Post]mello dude, on Aug 26 2009, 08:15 PM, said:

[image: View Post]coderighter, on Aug 26 2009, 09:00 PM, said:

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.

Why not just stick in the VTR Fan?
http://www.vfrdiscussion.com/forum/index.p...mp;#entry640043

MD

I saw that thread. The fact is, the fan pulling air from the cooler side is a better idea when the bike is either not stopped or slow, when a fan is useful. As part of my testing, I installed a remote thermo sensor next to the fan frame. At one point while waiting at a stop light on a 90 degree day, just before the fan kicked on, the temp read 157 degrees. I don't think that pushing 157 degree air through the radiator is going to be real effective. Plus by pushing air, you add the heat of the fan motor, which is quite a bit.

I believe the factory fan setup will do the best job, but it just needs to not run and counter act natural air flow will the bike gets up to speed. When the bike is up to speed, no fan is going to help anyway. The only time I could see a reverse fan would help, would be that short time that you're moving fast enough to remove the hot air in the "tunnel" (15-20 mph), but below 30-40 mph when the fan is not useful anyway.

Plus, leaving the fan standard rotation and turning off when "not needed" should double it's useful life. Also, because the natural air flow is working against the fan when the bike is moving the fan working harder and is actually drawing more current, taxing the alternator and charging system for no reason. This makes the fan motor, alternator, and engine (increased load) hotter. I know small, but it all adds up.


Side note, after I lessen the fan run time, I'm changing the thermo switch to 210 at the next antifreeze change. If I did that now, the fan would run way too much. In city traffic, the fan would actually keep the bike hot.

well I did not see that before my last post, and I did not do any serious research like you did, but I can tell you this.
the VTR fan works, before I added it my 01 would get way up into the 230+ range and stay there pretty much as along as the fan was on.
So even if the area near the frame was 157 degrees before the fan kicks on, its still cooler than the 230+ that the rad's are going to climb to.

Besides once you get the air moving out, the bike is not going to be heating that airspace to 157.

The reality is that with the new fan blade from the vtr, the fan comes on at 224 and the temperature drops, not rises like before, Drops. It runs in cycles like it is supposed to instead of coming on and just staying on until you get back up roughly 35 mph. To me its obvious that it works.


As a plus anytime the fan is running and the bike gets moving the fan first freewheels, then begins generating its own power (like a mobil wind turbine).
It's not efficient at this, but it has to reduce the load.






That's cool, (pardon the pun) I'm glad that works for you. Still I have to believe that pulling fresh air, almost half the temp of the "tunnel air", does alot better job of cooling. Once the bike is in motion above 30-35 mph, the fan doesn't matter anyway. It seems to me that I've read, while working on another project years ago, that the effect of outside air temp on a thermal performance of an radiator is a logarithmic scale. That being, the efficiency of heat transfer increases at a compound rate as the outside temp decreases. IMO

[image: View Post]coderighter, on Aug 27 2009, 10:07 PM, said:

That's cool, (pardon the pun) I'm glad that works for you. Still I have to believe that pulling fresh air, almost half the temp of the "tunnel air", does alot better job of cooling. Once the bike is in motion above 30-35 mph, the fan doesn't matter anyway. It seems to me that I've read, while working on another project years ago, that the effect of outside air temp on a thermal performance of an radiator is a logarithmic scale. That being, the efficiency of heat transfer increases at a compound rate as the outside temp decreases. IMO

I'm not about to try and remember all the details about thermal transfer from a radiator to ambient air scales.
Yeah for given volume of flow through the radiator, cooler ambient air will transfer more heat.
And once the bike is moving at or above 30 mph the fan is not a requirement.

But there are some issues with your argument.
First, you say half the temp of the 'tunnel air' -- I don't know about you but, I saw ambient temps above 105 degrees in traffic as recently as last week. Add in the high humidity on those days and the ambient index in the traffic was well into the 125 range. 125 vs 157 is not that much more efficient and when you add in that the heat is not getting evacuated from the bike just moved around, its pretty obvious that the fan is not really working to the best of its abilities.
Second, you want to switch it off when you get the bike up to 30 mph, which is not where the problem is. The problem is that as soon as the bike starts moving, the oem fan is bucking flow, its pushing heat back into the bike - across, down and back not out. Everything on the bike gets heated, and you can plainly see that on your bike as it doesn't begin to cool down until you get up 30mph. For the switch to really be effective, you would have to have it cut the fan out at a much lower speed, so that natural cooling flow can be re-established and the temps can begin to drop. What would the best speed to cut out the fan, I don't know, but I'd bet it was very very low (probably something ridiculous like <10mph).

Your desire to turn the fan off when the bike is moving, just points to how flawed the factory design is. Any cooling fan is supposed to augment the radiators ability to cool, and anytime that the design has such a negative result, it should be considered a flawed design.
Many Honda Bikes have this pull in design and they all have static and low speed heating issues.
5th generation VFR's,
6th generation VFR's,
sp1 and sp2 RC51's,
even the Mighty GL1800 Goldwings had it (until honda issued a recall that swapped out the fan for a "pusher" unit.)

let me ask you this as its the only down side I can find to this modification. Would you rather worry about a little heat flowing past your left leg or would you rather have your bike possibly overheating in summer traffic because of a bad fan design???
I know which I would choose.

Or let me put it another way,
If you buy the fan blade and it doesn't fit on your bike. I buy the fan blade from you and I'll tell you how to make it work with your original fan blade.
Its a whole lot more work than just bolting on a new blade, but it can be done. I'm doing that right now with the fans on my RC.

[image: View Post]JES_VFR, on Aug 27 2009, 10:43 PM, said:

[image: View Post]coderighter, on Aug 27 2009, 10:07 PM, said:

That's cool, (pardon the pun) I'm glad that works for you. Still I have to believe that pulling fresh air, almost half the temp of the "tunnel air", does alot better job of cooling. Once the bike is in motion above 30-35 mph, the fan doesn't matter anyway. It seems to me that I've read, while working on another project years ago, that the effect of outside air temp on a thermal performance of an radiator is a logarithmic scale. That being, the efficiency of heat transfer increases at a compound rate as the outside temp decreases. IMO

I'm not about to try and remember all the details about thermal transfer from a radiator to ambient air scales.
Yeah for given volume of flow through the radiator, cooler ambient air will transfer more heat.
And once the bike is moving at or above 30 mph the fan is not a requirement.

But there are some issues with your argument.
First, you say half the temp of the 'tunnel air' -- I don't know about you but, I saw ambient temps above 105 degrees in traffic as recently as last week. Add in the high humidity on those days and the ambient index in the traffic was well into the 125 range. 125 vs 157 is not that much more efficient and when you add in that the heat is not getting evacuated from the bike just moved around, its pretty obvious that the fan is not really working to the best of its abilities.
Second, you want to switch it off when you get the bike up to 30 mph, which is not where the problem is. The problem is that as soon as the bike starts moving, the oem fan is bucking flow, its pushing heat back into the bike - across, down and back not out. Everything on the bike gets heated, and you can plainly see that on your bike as it doesn't begin to cool down until you get up 30mph. For the switch to really be effective, you would have to have it cut the fan out at a much lower speed, so that natural cooling flow can be re-established and the temps can begin to drop. What would the best speed to cut out the fan, I don't know, but I'd bet it was very very low (probably something ridiculous like <10mph).

Your desire to turn the fan off when the bike is moving, just points to how flawed the factory design is. Any cooling fan is supposed to augment the radiators ability to cool, and anytime that the design has such a negative result, it should be considered a flawed design.
Many Honda Bikes have this pull in design and they all have static and low speed heating issues.
5th generation VFR's,
6th generation VFR's,
sp1 and sp2 RC51's,
even the Mighty GL1800 Goldwings had it (until honda issued a recall that swapped out the fan for a "pusher" unit.)

let me ask you this as its the only down side I can find to this modification. Would you rather worry about a little heat flowing past your left leg or would you rather have your bike possibly overheating in summer traffic because of a bad fan design???
I know which I would choose.

Or let me put it another way,
If you buy the fan blade and it doesn't fit on your bike. I buy the fan blade from you and I'll tell you how to make it work with your original fan blade.
Its a whole lot more work than just bolting on a new blade, but it can be done. I'm doing that right now with the fans on my RC.






The reverse fan works for you, OK. When I had the 157 degree reading, the ambient was 90 (inside / outside thermo). The difference of 67 is pretty big. The stock fan actually does a pretty good job under 15-20 mph and I don't ride between 20-30 mph. By 30 mph the fan will be off, so I should do pretty well from then on.

I checked and by the time I pay for the reverse fan with tax and/or shipping, I'm looking at close to $40. I had most of the parts on hand to build the module. I think I got about $5 into it, maybe $10 if you count the stuff I had on hand.

The reverse fan worked for you, I think stopping the fan will work just fine for me.

[image: View Post]mello dude, on Aug 26 2009, 09:12 PM, said:

My background is automotive engineering so I thought well yeah why not dig into gettng a custom batch of switches. Cant give any details as of yet, the supplier may decide he doesnt want to fool with it.

MD

Any news on this, I mean I would happily take two.
One for the VFR, just to try.
And one for the RC as 227 as a switch on point is too high a startup threshold and 213 is not low enough for a cut-off.
I'm still going to finish the fan blade/reverse motor/mini shroud modifications one day soon.

Thank god the VFR doesn't need anything like that.

As a new GEN5.5 owner; 2000 VFR, I'm amazed at how lame the owner's manual is.

Is this indeed the temp my fan should turn on at?
The stocker fan switch comes on at about 219 F degrees

^ ^ ^

Somebody???

[image: View Post]TripleH, on 03 May 2010 - 09:27 AM, said:

As a new GEN5.5 owner; 2000 VFR, I'm amazed at how lame the owner's manual is.

Is this indeed the temp my fan should turn on at?
The stocker fan switch comes on at about 219 F degrees



The fans on both my 5th and 6h gens come on at 104�C and turn off at 96�C... religiously... until of course you've spent all day caning the hell out of them on curvey uphill runs on hot (40-45�C) summer days... for some reason, the longer they spend at high temps, the later they come on and the longer they stay on... I've had my VFRs run so hot for so long that the fan just stopped coming on.. at this point I turned the bike off and took a breather...

[image: View Post]Auspa�ol, on 04 May 2010 - 09:20 AM, said:

The fans on both my 5th and 6h gens come on at 104�C and turn off at 96�C... religiously...
96= 204.8 degree Fahrenheit
104= 219.2 degree Fahrenheit

Ok, I have not seen anything hotter than 211, so maybe my fan is fine, it just has not gotten hot enough to turn on
The manual said the critical top temp was 251
Thanks!

Coderighter and Jess... interesting debate... all of those factors and possible mods have been discused here before in great detail...

Based on my experiments with the VTR fan I can safely say the following:

It rocks when the bike is in motion. Very effective.

It sucks when the bike is stationary. So much so that if you enter into a slow speed zone, like going through a small city/large town on your way somewhere, travelling on say, secondary highwyas (don't know the US term)... and the bike is already close to climax (hehehe)... you stop at a red light (one that lasts a while cause it's like a 6 way intersection or something, or for whatever reason)...maybe you've had to stop at several intersections, but the frame and all the other bits and air immediately surrounding the motor and bike are hotter... and the ambient temp is high... the VTR fan will not get the coolant temp down to the lower cut-off point... it will just keep coming on until it stays on unless you get to run the bike at about 70 km/h for a good run...

More later, gotta go to a Microbiology exam and I'm running late ...

[image: View Post]Auspa�ol, on 04 May 2010 - 09:26 AM, said:

More later, gotta go to a Microbiology exam and I'm running late ...
Hope ya did well on your test

As someone who has swapped out to the VTR fan all I can say is that it was a simple swap and it just WORKS.

No messing around with a manual switch, no messing around re-wiring anything. It just WORKS.

The only downside is that the bike throws out some serious HEAT onto your left leg and if you are wearing something other than real moto pants or a 1-piece moto suit it becomes uncomfortable. I did some test riding around the block with my new fan and OMG HOT AIR ON MY LEG! But when I put my 'stich suit on it's not even noticed.

So, if you want to wear shorts or a light pair of cotton pants you might not like the bike actually COOLING ITSELF by throwing heat OUT of the engine compartment rather than right back inside it. I guess Honda made a decision that having a bike that ran way too hot in Stop & Go traffic and sometimes overheated was better than having the squids who rode without proper gear bitching and complaining about hot air hitting their leg when they rode in shorts and flip-flops.

That's just how I see it.

I'd rather have a radiator and cooling system that WORKED. The VTR fan swap works. I'm a bit insulted that Honda would sacrifice an effective system to keep a few squid's leg's cool because they weren't wearing decent leg protection that would insulate their knee/upper leg from the isolated blast from the left radiator. The only way I can feel it is if I pull off my glove and feel the outside of my 'stich at my knee. Yeah, it's warm (not melting hot -but quite warm). But I can't feel it through the fabric inside.

Thick abrasion-resistant and insulating clothing works both ways.

I'm glad I found this thread, I'll have to keep an eye on it
As I have only 203 VFR miles under my belt and it is clearly anything but hot here yet, I'm not sure what to expect
One thing though, I will not give up the way I ride, I will not lumber through a 30-mph zone shifted way up into a higher gear to keep the rpms/temps down
If I can't rumble my Staintune through town at 30-mph at 5,000 rpm's without overheating, I will indeed have to make some kind of change

[image: View Post]coderighter, on 26 August 2009 - 08:00 PM, said:

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.


I think on the part that I highlighted in bold, you are off on the direction of the airflow when the bike is in motion. The aerodynamics of the bike cause the air to flow around the outside of the fairing. The fairing is open behind the wheel allowing the bike to breath from inside. Therefore, in stock form, when moving at speed, the fan is rendered useless. The natural flow of air around the bike and over the hole that the radiator is placed inside causes air to be drawn from inside the fairings outward. When at speed however, the fan is not required. There is enough natural airflow over the engine, headers, and through the radiator that a fan is not needed anyways and will turn off when temperatures drop in range. Honda did this intentionally.

When at a stop, I couldn't agree more. I would rather leave the fan alone and allow it to draw cooler air from the outside in. Naturally this will do better when at a stop. I can see the VTR fan being beneficial only when moving, it will just assist the natural draw of air that Honda decided to come inside to out. But I also feel Honda knows that when moving the temperatures will not require a fan. That is why they have it pulling from outside.

For those of you questioning my theory on the air flow around the fairings drawing air out, have you ever taken two straws, placed one in a drink, then blown over the top of the straw with the second one? It will create a vacuum drawing the drink up.

[image: View Post]Auspa�ol, on 04 May 2010 - 09:26 AM, said:

Coderighter and Jess... interesting debate... all of those factors and possible mods have been discused here before in great detail...

Based on my experiments with the VTR fan I can safely say the following:

It rocks when the bike is in motion. Very effective.

It sucks when the bike is stationary. So much so that if you enter into a slow speed zone, like going through a small city/large town on your way somewhere, travelling on say, secondary highwyas (don't know the US term)... and the bike is already close to climax (hehehe)... you stop at a red light (one that lasts a while cause it's like a 6 way intersection or something, or for whatever reason)...maybe you've had to stop at several intersections, but the frame and all the other bits and air immediately surrounding the motor and bike are hotter... and the ambient temp is high... the VTR fan will not get the coolant temp down to the lower cut-off point... it will just keep coming on until it stays on unless you get to run the bike at about 70 km/h for a good run...

More later, gotta go to a Microbiology exam and I'm running late ...


I commute in traffic daily, so the current configuration makes more sense. With that said, I wouldn't mind it coming on at an earlier temperature due to the heat I get here. I see 225 a lot with an occasional 230 which makes me uncomfortable.

[image: View Post]Cogs69, on 04 May 2010 - 02:02 PM, said:

[image: View Post]coderighter, on 26 August 2009 - 08:00 PM, said:

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.


I think on the part that I highlighted in bold, you are off on the direction of the airflow when the bike is in motion. The aerodynamics of the bike cause the air to flow around the outside of the fairing. The fairing is open behind the wheel allowing the bike to breath from inside. Therefore, in stock form, when moving at speed, the fan is rendered useless. The natural flow of air around the bike and over the hole that the radiator is placed inside causes air to be drawn from inside the fairings outward. When at speed however, the fan is not required. There is enough natural airflow over the engine, headers, and through the radiator that a fan is not needed anyways and will turn off when temperatures drop in range. Honda did this intentionally.

When at a stop, I couldn't agree more. I would rather leave the fan alone and allow it to draw cooler air from the outside in. Naturally this will do better when at a stop. I can see the VTR fan being beneficial only when moving, it will just assist the natural draw of air that Honda decided to come inside to out. But I also feel Honda knows that when moving the temperatures will not require a fan. That is why they have it pulling from outside.

For those of you questioning my theory on the air flow around the fairings drawing air out, have you ever taken two straws, placed one in a drink, then blown over the top of the straw with the second one? It will create a vacuum drawing the drink up.

[image: View Post]Auspa�ol, on 04 May 2010 - 09:26 AM, said:

Coderighter and Jess... interesting debate... all of those factors and possible mods have been discused here before in great detail...

Based on my experiments with the VTR fan I can safely say the following:

It rocks when the bike is in motion. Very effective.

It sucks when the bike is stationary. So much so that if you enter into a slow speed zone, like going through a small city/large town on your way somewhere, travelling on say, secondary highwyas (don't know the US term)... and the bike is already close to climax (hehehe)... you stop at a red light (one that lasts a while cause it's like a 6 way intersection or something, or for whatever reason)...maybe you've had to stop at several intersections, but the frame and all the other bits and air immediately surrounding the motor and bike are hotter... and the ambient temp is high... the VTR fan will not get the coolant temp down to the lower cut-off point... it will just keep coming on until it stays on unless you get to run the bike at about 70 km/h for a good run...

More later, gotta go to a Microbiology exam and I'm running late ...


I commute in traffic daily, so the current configuration makes more sense. With that said, I wouldn't mind it coming on at an earlier temperature due to the heat I get here. I see 225 a lot with an occasional 230 which makes me uncomfortable.


My Gen5 never had a cooling problem at speed -or at a stop (not that I ever felt the need to run the engine when I wasn't moving -or about to be moving in the next minute or so). It only had an issue when in stop&go traffic that never got up to 30MPH for more than a couple of seconds and then coasted back to a walking pace. The bike would get up to 230-240 degrees.

Now, with the VTR fan, it never sees anything over 220. I live and commute in and out of Chicago for much of the year. We get our share of stop & go traffic. It sucked in the stock configuration. It just works now.

YMMV

This will be the first full season on my '98 with the VTR fan swap. I did it last year in June and our summer here was the 2nd coolest on record, so I didnt really get a good read on liking or disliking the VTR fan. - I'll see how it goes for this season.

The bike does get hot fast in stop n go traffic and sitting still. The ambient temp really doesnt matter.- My fan does kick on at 219F, but still kinda drives me nutz. It's probably fine, but still would like to screw with bit lower temp fan switch. - Never really got a good wish list on/off temps from the gang here so it the idea kinda died.

[image: View Post]Cogs69, on 04 May 2010 - 02:02 PM, said:

[image: View Post]coderighter, on 26 August 2009 - 08:00 PM, said:

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.


I think on the part that I highlighted in bold, you are off on the direction of the airflow when the bike is in motion. The aerodynamics of the bike cause the air to flow around the outside of the fairing. The fairing is open behind the wheel allowing the bike to breath from inside. Therefore, in stock form, when moving at speed, the fan is rendered useless. The natural flow of air around the bike and over the hole that the radiator is placed inside causes air to be drawn from inside the fairings outward. When at speed however, the fan is not required. There is enough natural airflow over the engine, headers, and through the radiator that a fan is not needed anyways and will turn off when temperatures drop in range. Honda did this intentionally.

When at a stop, I couldn't agree more. I would rather leave the fan alone and allow it to draw cooler air from the outside in. Naturally this will do better when at a stop. I can see the VTR fan being beneficial only when moving, it will just assist the natural draw of air that Honda decided to come inside to out. But I also feel Honda knows that when moving the temperatures will not require a fan. That is why they have it pulling from outside.

For those of you questioning my theory on the air flow around the fairings drawing air out, have you ever taken two straws, placed one in a drink, then blown over the top of the straw with the second one? It will create a vacuum drawing the drink up.

[image: View Post]Auspañol, on 04 May 2010 - 09:26 AM, said:

Coderighter and Jess... interesting debate... all of those factors and possible mods have been discused here before in great detail...

Based on my experiments with the VTR fan I can safely say the following:

It rocks when the bike is in motion. Very effective.

It sucks when the bike is stationary. So much so that if you enter into a slow speed zone, like going through a small city/large town on your way somewhere, travelling on say, secondary highwyas (don't know the US term)... and the bike is already close to climax (hehehe)... you stop at a red light (one that lasts a while cause it's like a 6 way intersection or something, or for whatever reason)...maybe you've had to stop at several intersections, but the frame and all the other bits and air immediately surrounding the motor and bike are hotter... and the ambient temp is high... the VTR fan will not get the coolant temp down to the lower cut-off point... it will just keep coming on until it stays on unless you get to run the bike at about 70 km/h for a good run...

More later, gotta go to a Microbiology exam and I'm running late ...


I commute in traffic daily, so the current configuration makes more sense. With that said, I wouldn't mind it coming on at an earlier temperature due to the heat I get here. I see 225 a lot with an occasional 230 which makes me uncomfortable.



I for one don't doubt the vacume effect you describe, although I can guarantee you some air also flows straight into the engine bay between the forks and thus flows through the radiators from the inside out, this complements the vacume effect you mention and the degree to which both are in play would depend on forward speed I guess.

Where I would differ is in the fact that, I have experienced umpteen times just how the inflowing air makes the fan rendered useless when it's on to the point where (at lower than 70 km/h) the bike does not cool down... I'm talking really hot summers and half an hour in stop&go traffic for example... & thus the fan would labour on continuously until, A: you get on a freeway/highway & at speed +80 km/h & the force of the oncoming air overcomes the fan, or B: you go so slow (or stop) that the fan can do its job.

The VTR fan worked (for me) when I didn't spend too much time stopping and going... on my 5th gen I've had to pull over and turn it off cause it just wasn't capable of cooling the thing down enough... I often found myself longing for a stretch of freeway to get up to speed.

With the OEM fan, I figured out how to wire up a switch to turn the fan off for when I'm moving forward and the fan is on... so the air can do it's job...

Having the fan running continuously is putting the VFR's fairly dodgy charging system under extra load for longer... same would happen if you drop in a thermoswitch with lower activation values... it'll come on more often... it is a fairly hot running bike by design as far as I can figure...

But hey... every VFR is a little different... some fry stators some don't... some run that bit hotter than others... and the weather here is extremely hot over summer... +40ºC is extreme... and the asphalt and surrounding buildings are radiating even more heat.. like at MotoGP... the track temp is always way higher than ambient...

I'm glad the VTR fan works so well for others...

Experiment I say, and find out what works for you....

[image: View Post]Auspa�ol, on 04 May 2010 - 09:20 AM, said:

The fans on both my 5th and 6h gens come on at 104�C and turn off at 96�C... religiously...

96= 204.8 degree Fahrenheit
104= 219.2 degree Fahrenhe

THANKS
I let the bike sit until it got up to 219, and bingo, on came the fan
I feel so much better knowing when it is supposed to come on, and of course, that it does indeed work and come on

[image: View Post]Serenity_VFR, on 04 May 2010 - 01:29 PM, said:

As someone who has swapped out to the VTR fan all I can say is that it was a simple swap and it just WORKS.

No messing around with a manual switch, no messing around re-wiring anything. It just WORKS.

The only downside is that the bike throws out some serious HEAT onto your left leg and if you are wearing something other than real moto pants or a 1-piece moto suit it becomes uncomfortable. I did some test riding around the block with my new fan and OMG HOT AIR ON MY LEG! But when I put my 'stich suit on it's not even noticed.

So, if you want to wear shorts or a light pair of cotton pants you might not like the bike actually COOLING ITSELF by throwing heat OUT of the engine compartment rather than right back inside it. I guess Honda made a decision that having a bike that ran way too hot in Stop & Go traffic and sometimes overheated was better than having the squids who rode without proper gear bitching and complaining about hot air hitting their leg when they rode in shorts and flip-flops.

That's just how I see it.

I'd rather have a radiator and cooling system that WORKED. The VTR fan swap works. I'm a bit insulted that Honda would sacrifice an effective system to keep a few squid's leg's cool because they weren't wearing decent leg protection that would insulate their knee/upper leg from the isolated blast from the left radiator. The only way I can feel it is if I pull off my glove and feel the outside of my 'stich at my knee. Yeah, it's warm (not melting hot -but quite warm). But I can't feel it through the fabric inside.

Thick abrasion-resistant and insulating clothing works both ways.

DUDE, if you think that the VFR can warm your one bare leg, you should try my RC51 with it's reversed fans. It will toast both your legs when the fans are running, but that is still better than just hearing the fans kick on and then just watching the temps still rise to 245.
Oh, yeah one other thing. And I discovered this with my one piece Infinity suit. The suit will insulate you up to a point and then it will match ambient temperatures, so you still need to have a layer on that can insulate you from the outside temp enough. So if its hot better plan on something that will just keep the suit off your bare skin or you will swear it burning you.

I don't know what Auspa�ol is saying about it his VTR fan is not cooling enough, In fact he's the only one that I know of that has tried the fan swap and says that it doesn't work well enough.

Auspa�ol, What did your VFR do before you swapped the fan blade? I mean if you are still having issues with the VTR fan, then I hate to think what heat issues you were having with the stock fan. And just to clarify, you did just install a new VTR fan blade on the VFR honda's fan motor correct?
I'm asking this because the VFR/VTR fan swap was like nothing compared to changing the direction of airflow on the rc51.

Hey Mello Dude, any chance of getting you to make those switches after all?
How many interested parties or wanted switches would you need to make it worth the effort?

[image: View Post]Serenity_VFR, on 04 May 2010 - 01:29 PM, said:

As someone who has swapped out to the VTR fan all I can say is that it was a simple swap and it just WORKS.

No messing around with a manual switch, no messing around re-wiring anything. It just WORKS.

The only downside is that the bike throws out some serious HEAT onto your left leg and if you are wearing something other than real moto pants or a 1-piece moto suit it becomes uncomfortable. I did some test riding around the block with my new fan and OMG HOT AIR ON MY LEG! But when I put my 'stich suit on it's not even noticed.

So, if you want to wear shorts or a light pair of cotton pants you might not like the bike actually COOLING ITSELF by throwing heat OUT of the engine compartment rather than right back inside it. I guess Honda made a decision that having a bike that ran way too hot in Stop & Go traffic and sometimes overheated was better than having the squids who rode without proper gear bitching and complaining about hot air hitting their leg when they rode in shorts and flip-flops.

That's just how I see it.

I'd rather have a radiator and cooling system that WORKED. The VTR fan swap works. I'm a bit insulted that Honda would sacrifice an effective system to keep a few squid's leg's cool because they weren't wearing decent leg protection that would insulate their knee/upper leg from the isolated blast from the left radiator. The only way I can feel it is if I pull off my glove and feel the outside of my 'stich at my knee. Yeah, it's warm (not melting hot -but quite warm). But I can't feel it through the fabric inside.

Thick abrasion-resistant and insulating clothing works both ways.

DUDE, if you think that the VFR can warm your one bare leg, you should try my RC51 with it's reversed fans. It will toast both your legs when the fans are running, but that is still better than just hearing the fans kick on and then just watching the temps still rise to 245.
Oh, yeah one other thing. And I discovered this with my one piece Infinity suit. The suit will insulate you up to a point and then it will match ambient temperatures, so you still need to have a layer on that can insulate you from the outside temp enough. So if its hot better plan on something that will just keep the suit off your bare skin or you will swear it burning you.

I don't know what Auspa�ol is saying about it his VTR fan is not cooling enough, In fact he's the only one that I know of that has tried the fan swap and says that it doesn't work well enough.

Auspa�ol, What did your VFR do before you swapped the fan blade? I mean if you are still having issues with the VTR fan, then I hate to think what heat issues you were having with the stock fan. And just to clarify, you did just install a new VTR fan blade on the VFR honda's fan motor correct?
I'm asking this because the VFR/VTR fan swap was like nothing compared to changing the direction of airflow on the rc51.

Hey Mello Dude, any chance of getting you to make those switches after all?
How many interested parties or wanted switches would you need to make it worth the effort?

[image: View Post]TripleH, on 04 May 2010 - 01:45 PM, said:

I'm glad I found this thread, I'll have to keep an eye on it
As I have only 203 VFR miles under my belt and it is clearly anything but hot here yet, I'm not sure what to expect
One thing though, I will not give up the way I ride, I will not lumber through a 30-mph zone shifted way up into a higher gear to keep the rpms/temps down
If I can't rumble my Staintune through town at 30-mph at 5,000 rpm's without overheating, I will indeed have to make some kind of change

The rpm's are not the big deal, and if you are moving at 30mph, then you should be just fine.
at that speed you should have enough air flow even with the fan trying to run to keep the cooling system working and the bike running right.

This fan issue is really more something that rears it's ugly head when you hit stop and go traffic.
The the OEM fan just doesn't move the heat away from the bike, so it quickly hits the point where the fan is running 100% of the time and the coolant temp keeps on rising.

[image: View Post]Auspañol, on 04 May 2010 - 05:42 PM, said:

Based on my experiments with the VTR fan I can safely say the following:

It rocks when the bike is in motion. Very effective.
It sucks when the bike is stationary. So much so that if you enter into a slow speed zone, like going through a small city/large town on your way somewhere, travelling on say, secondary highwyas (don't know the US term)... and the bike is already close to climax (hehehe)... you stop at a red light (one that lasts a while cause it's like a 6 way intersection or something, or for whatever reason)...maybe you've had to stop at several intersections, but the frame and all the other bits and air immediately surrounding the motor and bike are hotter... and the ambient temp is high... the VTR fan will not get the coolant temp down to the lower cut-off point... it will just keep coming on until it stays on unless you get to run the bike at about 70 km/h for a good run...
Again, this makes me wonder what you VFR's were like with the oem fans. I have had my VTR fan kick on in stop and go traffic on an UBER-Hot day, cycle on and off couple of times and then not shut off again until the I cleared the traffic. If the heat index is high enough that is normal. But I've never had it kick in at 223-224, cycle a couple of times then run continuously and still have the temperature keep rising until its 240+ (which the VFR did all the time with the oem fan blade) The most I've ever seen was 234 after a twenty minute delay on a day that I later learned the ambient heat index as 158. The asphalt was so hot you could see the oils and tars rising through the aggregate.
That oem fan never cycled in traffic, it would come on and just stay running 100%, with the temps just rising.

[image: View Post]Auspañol, on 04 May 2010 - 05:42 PM, said:

Where I would differ is in the fact that, I have experienced umpteen times just how the inflowing air makes the fan rendered useless when it's on to the point where (at lower than 70 km/h) the bike does not cool down... I'm talking really hot summers and half an hour in stop&go traffic for example... & thus the fan would labour on continuously until, A: you get on a freeway/highway & at speed +80 km/h & the force of the oncoming air overcomes the fan, or B: you go so slow (or stop) that the fan can do its job.
Its more like a).you speed up to a speed where the air flow through the right radiator does enough of the job that the bike cools down and shuts off the fan or b). You pull over and stop and wait for the bike to cool down on it's own.

[image: View Post]Auspañol, on 04 May 2010 - 05:42 PM, said:

The VTR fan worked (for me) when I didn't spend too much time stopping and going... on my 5th gen I've had to pull over and turn it off cause it just wasn't capable of cooling the thing down enough... I often found myself longing for a stretch of freeway to get up to speed.
Well, hang on a second, are you saying that the VTR fan did could not hold temperature or that it could not necessarily bring it back down below the fan cut off temperature.
If the fan ran and held the temp at 223, then it was working just fine. Just like the ac compressor in a car, conditions are often such that it cannot cycle on and off. As long as its running and the temperature does not just keep climbing then the fan is working.

With the OEM fan, I figured out how to wire up a switch to turn the fan off for when I'm moving forward and the fan is on... so the air can do it's job...

[image: View Post]Auspañol, on 04 May 2010 - 05:42 PM, said:

Having the fan running continuously is putting the VFR's fairly dodgy charging system under extra load for longer... same would happen if you drop in a thermoswitch with lower activation values... it'll come on more often... it is a fairly hot running bike by design as far as I can figure...
If the fan is running and the bike is not moving then its true its a load on the charging system. However it is a necessary evil as the alternate is the bike overheats.
But with the VTR fan once the bike is moving the electrical load from the fan drops to almost nothing as the natural air flow through the radiator wants to spin that fan like pinwheel. In fact the fan motor almost generates power at that point. So it's sort of a win/win.
Now while the fan would run more often if its switch's temperature thresholds were changed, I don't think that it would be bad. I think it would cycle more and run continuously less.
The whole bike would be cooler and that is a pretty serious mass of metal we are trying to cool. It is a hot running bike by design, but that doesn't mean that keeping it in its sweet spot is a bad idea.

[image: View Post]Auspañol, on 04 May 2010 - 05:42 PM, said:

But hey... every VFR is a little different... some fry stators some don't... some run that bit hotter than others... and the weather here is extremely hot over summer... +40ºC is extreme... and the asphalt and surrounding buildings are radiating even more heat.. like at MotoGP... the track temp is always way higher than ambient...

I'm glad the VTR fan works so well for others...
Experiment I say, and find out what works for you....

That is why I keep thinking about building a fan controller to make the fan more effective. Sort of a cross over from an automotive electrical cooling fan adventure.

[image: View Post]coderighter, on 27 August 2009 - 11:30 PM, said:

The reverse fan works for you, OK. When I had the 157 degree reading, the ambient was 90 (inside / outside thermo). The difference of 67 is pretty big. The stock fan actually does a pretty good job under 15-20 mph and I don't ride between 20-30 mph. By 30 mph the fan will be off, so I should do pretty well from then on.

I checked and by the time I pay for the reverse fan with tax and/or shipping, I'm looking at close to $40. I had most of the parts on hand to build the module. I think I got about $5 into it, maybe $10 if you count the stuff I had on hand.

The reverse fan worked for you, I think stopping the fan will work just fine for me.



CR,

I came to the same conclusion several years back, but lack the wherewithall to pull off what you're doing. I don't know if you're interested in putting another module together, but I'd be interested if you are.

thanks,

Jim

[quote name='JES_VFR' date='28 May 2010 - 03:16 PM' timestamp='1275074171' post='710279']
[quote name='Serenity_VFR' date='04 May 2010 - 02:29 PM' timestamp='1272997769' post='704309']

Hey Mello Dude, any chance of getting you to make those switches after all?
How many interested parties or wanted switches would you need to make it worth the effort?
[/quote]

- I do have a vendor in mind to give it a shot, they make automotive fan switches for a living. I still like this heat discussion and kinda wonder if we go too low on the temp on/off, would we get to a point where the fan wont shut off? Then what happens with the system electrics? Something to think about.

- Another curve ball in this thing is there seems to be a wide variance of vfr heat issues. Some seem to be totally fine stock, and others are a problem child. Theres something going on there and I dont know what it is.

- If I had enuff interest, I suppose I would ask the vendor to quote me a batch of 50 and 100 to see where the price tag would go. For the moment I couldnt guess what they would charge. I'm willing to work with you guys if I get some interest.

[quote name='mello dude' date='28 May 2010 - 06:04 PM' timestamp='1275084269' post='710312']
[quote name='JES_VFR' date='28 May 2010 - 03:16 PM' timestamp='1275074171' post='710279']
[quote name='Serenity_VFR' date='04 May 2010 - 02:29 PM' timestamp='1272997769' post='704309']

Hey Mello Dude, any chance of getting you to make those switches after all?
How many interested parties or wanted switches would you need to make it worth the effort?
[/quote]

- I do have a vendor in mind to give it a shot, they make automotive fan switches for a living. I still like this heat discussion and kinda wonder if we go too low on the temp on/off, would we get to a point where the fan wont shut off? Then what happens with the system electrics? Something to think about.
You make a valid point that If we go to low the fan won't ever stop running, but I do think that it stand to be triggered a few degrees (say 15-25) earlier than the stock one.

- Another curve ball in this thing is there seems to be a wide variance of vfr heat issues. Some seem to be totally fine stock, and others are a problem child. Theres something going on there and I dont know what it is.
I think this is two things, one some of us ride everywhere and must deal with traffic issues frequently and often. Where as others don't. That along with lots of variations in temp and humidity, not mention conditions and concentration of coolant have to effect, results. If we took 15 vfr's from three generations and rode them all in the same conditions for a week in hot conditions (say 95F and over 85% humidity, at rush hour in the city traffic), I bet that we would see some heating issues in several of the bikes. Not all, but quite a few.

Also there are several different expectations when it comes to the performance of the fan. Some think that its only working if it can drop the coolant temp back down to the cutoff point no matter what the ambient conditions are. Some think that if the fan comes on that the temp should at least freeze exactly where the fan kicks on and if it doesn't then it isn't working either (again the conditions don't matter. The last group recognizes that the fan is working if it stabilizes the engine temp in a range that is less than boiling the coolant, but that the ambient conditions may push the temp higher than they normally expect (like on a day when the heat index hits 165 at rush hour)

- If I had enuff interest, I suppose I would ask the vendor to quote me a batch of 50 and 100 to see where the price tag would go. For the moment I couldnt guess what they would charge. I'm willing to work with you guys if I get some interest.
[/quote]

Well I would take several, to install on my current bikes and to have on hand for replacement and other projects.
So you can count in for 5 or 6

My experience is that when I'm riding in traffic, the temperature will gradually creep up, because the column of traffic entrains the air, so instead of there being a positive pressure in front of the engine and low pressure either side of the bike, there's little air movement. Once the traffic's doing more than say 40mph, that changes. This is worse in summer than winter. On the open road, I've never had problems with the bike getting hot.
I fitted a manual switch that I trigger whenever I'm stationary and the temperature gets above about 90C. Originally I was going to fit another thermoswitch that I found that was set to go on at 95 and off at 85C (IIRC). I decided against this, as there would be too many times when it would be on and I'd be moving. So far, apart from forgetting to turn it off, the manual switch has worked out well. I may add a red light on the dash to remind me to turn it off.

I'd be interested in a lower temp fan switch as well MD. I had a nice 1.5hr commute at walking pace Thurs due to some massive accident. Stop & go traffic on the highway, bailed off onto secondary roads, which were also all creeping stop & go. Fan was running constantly, to the point where the battery drained & it died on me on the highway. Fortunately I unplugged the headlights and a guy stopped to help me bump start it (uphill, of course).
The fan was running the entire miserable ride, and never cooled below about 210, even on a few stretches where I got up to 55-60 for a mile or so.

Interesting discussion.
I have fitted the VTR fan and it works for me. I also have fitted a manual override switch so I can turn it on when ever I want, say when I know that I will be in slow moving traffic.

Its also interesting that Honda should bring out 2 bikes (VFR800 and VTR1000) with almost identical radiator setups and choose to have one fan sucking and the other blowing.

I have owned several of both bikes and the VTR1000 setup makes more sense to me.

If I could change the on / off temp of the thermoswitch, it would be to 95deg C ON and 90 deg C off

[image: View Post]dogman, on 29 May 2010 - 11:22 PM, said:

I have owned several of both bikes and the VTR1000 setup makes more sense to me.

I owned a VTR1000 before my current bike, a '90 VFR750 before that, and a '85 VF500 before that. All of them got hot in traffic, but the VFR800 is the least uncomfortable. The VTR tended to blow more eat out onto my leg, and all the bikes were somewhat uncomfortable on hot days due to heat from the rear headers. I think however that the current bike is the least worst.

[image: View Post]AndyJ, on 29 May 2010 - 06:28 AM, said:

I'd be interested in a lower temp fan switch as well MD. I had a nice 1.5hr commute at walking pace Thurs due to some massive accident. Stop & go traffic on the highway, bailed off onto secondary roads, which were also all creeping stop & go. Fan was running constantly, to the point where the battery drained & it died on me on the highway. Fortunately I unplugged the headlights and a guy stopped to help me bump start it (uphill, of course).
The fan was running the entire miserable ride, and never cooled below about 210, even on a few stretches where I got up to 55-60 for a mile or so.


I think this clearly illustrates a couple of points.
#1, Honda did not build an excess of cooling potential into the fan, In fact this case is argument that the factory suck fan is a epic sucking failure.
#2, It also proves that there us much more to the cooling issues that just atmospheric temperatures, there is "local" ambient temps, humidity and even other local conditions.

Now would the swapped fan blade and/or a lower temp switch have saved him? I don't know, I do think that those two items would have reduced the possible overheating, and perhaps reduced the electrical load a bit. Perhaps that would have been enough for him to keep bike charging and get to his destination without the joy of it quitting on the road.

[image: View Post]dogman, on 29 May 2010 - 11:22 PM, said:

Interesting discussion.
I have fitted the VTR fan and it works for me. I also have fitted a manual override switch so I can turn it on when ever I want, say when I know that I will be in slow moving traffic.

Its also interesting that Honda should bring out 2 bikes (VFR800 and VTR1000) with almost identical radiator setups and choose to have one fan sucking and the other blowing.

I have owned several of both bikes and the VTR1000 setup makes more sense to me.

If I could change the on / off temp of the thermoswitch, it would be to 95deg C ON and 90 deg C off


Don't forget the RC51, it as twin fans in suck mode where the VTR doesn't
Makes you wonder if Honda designers ever look at which past designs were successes.

[image: View Post]JES_VFR, on 30 May 2010 - 07:06 PM, said:

[image: View Post]dogman, on 29 May 2010 - 11:22 PM, said:

Interesting discussion.
I have fitted the VTR fan and it works for me. I also have fitted a manual override switch so I can turn it on when ever I want, say when I know that I will be in slow moving traffic.

Its also interesting that Honda should bring out 2 bikes (VFR800 and VTR1000) with almost identical radiator setups and choose to have one fan sucking and the other blowing.

I have owned several of both bikes and the VTR1000 setup makes more sense to me.

If I could change the on / off temp of the thermoswitch, it would be to 95deg C ON and 90 deg C off


Don't forget the RC51, it as twin fans in suck mode where the VTR doesn't
Makes you wonder if Honda designers ever look at which past designs were successes.


The RC has twin fans? Thats a new one on me. --Another goofy data point is that Gold Wings have the same issue with the radiators on the sides, and do the overheat thing on occasion too. Sometimes I wonder about Honda. On the one hand they are brilliant and on the other hand - idiots.

Wish numbers - I'm thinking 207deg F on, 194deg F off. -Better add a backup off switch on the fan just n case.

btw - I know the stocker on is 219, but what is stock off?

[image: View Post]mello dude, on 30 May 2010 - 07:28 PM, said:

[image: View Post]JES_VFR, on 30 May 2010 - 07:06 PM, said:

Don't forget the RC51, it as twin fans in suck mode where the VTR doesn't
Makes you wonder if Honda designers ever look at which past designs were successes.


The RC has twin fans? Thats a new one on me. --Another goofy data point is that Gold Wings have the same issue with the radiators on the sides, and do the overheat thing on occasion too. Sometimes I wonder about Honda. On the one hand they are brilliant and on the other hand - idiots.

Wish numbers - I'm thinking 207deg F on, 194deg F off. -Better add a backup off switch on the fan just n case.

btw - I know the stocker on is 219, but what is stock off?


Yup my RC51-SP2 had twin fans, one on each rad sucking in. To call it a hot bitch was an understatement when I got it.
So I did the usual things,
changed the coolant,
checked the thermostat,
confirmed that the fans were kicking in at the right temperatures and together.
I replaced a mis-sized and dying battery, and it solved a problem I had initially with bike dying at lights as soon as the fans switched on, but the bike would still roast at a traffic light.
I cut the coolant down to less than 5% of the mix and added lots of water wetter and still it would just get hotter when the fans were running.
finally I did some work on the fans (flipping the blades and reversing the fan motor rotation) and now it cools down. I can sit at a traffic light or in traffic and the hottest I have ever seen was 229 (and I was just about melting behind a NJT bus).
Sure I feel the heat on my lower legs for few minutes when the fans kick on, but that better than everything that touches the bike roasting for as long as you have it running and the bike overheating to boot.

Hey did you know that Honda had a recall on the early gl1800's to replace the tractor fan blade (the suck in fan) with a pusher fan blade to cure overheating issues.

[image: View Post]Serenity_VFR, on 04 May 2010 - 01:29 PM, said:

As someone who has swapped out to the VTR fan all I can say is that it was a simple swap and it just WORKS.

No messing around with a manual switch, no messing around re-wiring anything. It just WORKS.

The only downside is that the bike throws out some serious HEAT onto your left leg and if you are wearing something other than real moto pants or a 1-piece moto suit it becomes uncomfortable. I did some test riding around the block with my new fan and OMG HOT AIR ON MY LEG! But when I put my 'stich suit on it's not even noticed.

So, if you want to wear shorts or a light pair of cotton pants you might not like the bike actually COOLING ITSELF by throwing heat OUT of the engine compartment rather than right back inside it. I guess Honda made a decision that having a bike that ran way too hot in Stop & Go traffic and sometimes overheated was better than having the squids who rode without proper gear bitching and complaining about hot air hitting their leg when they rode in shorts and flip-flops.

That's just how I see it.

I'd rather have a radiator and cooling system that WORKED. The VTR fan swap works. I'm a bit insulted that Honda would sacrifice an effective system to keep a few squid's leg's cool because they weren't wearing decent leg protection that would insulate their knee/upper leg from the isolated blast from the left radiator. The only way I can feel it is if I pull off my glove and feel the outside of my 'stich at my knee. Yeah, it's warm (not melting hot -but quite warm). But I can't feel it through the fabric inside.

Thick abrasion-resistant and insulating clothing works both ways.


Yeh , whats the problem, The bike is designed to keep the heat off the rider and the cooling system does that very well .

The bike works as its supposed too, keeps the heat off the rider , Id rather have a warmer running engine than hot legs. I also ride in high heat post 100, the bike holds up great in stopped trafic the fan is extremely effective. I dont understand all the heat issue complaints at all.

so now your bike is cooler but you have to wear fire proof clothes, thats Funny!

[image: View Post]vfrjim2002, on 28 May 2010 - 04:05 PM, said:

[image: View Post]coderighter, on 27 August 2009 - 11:30 PM, said:

The reverse fan works for you, OK. When I had the 157 degree reading, the ambient was 90 (inside / outside thermo). The difference of 67 is pretty big. The stock fan actually does a pretty good job under 15-20 mph and I don't ride between 20-30 mph. By 30 mph the fan will be off, so I should do pretty well from then on.

I checked and by the time I pay for the reverse fan with tax and/or shipping, I'm looking at close to $40. I had most of the parts on hand to build the module. I think I got about $5 into it, maybe $10 if you count the stuff I had on hand.

The reverse fan worked for you, I think stopping the fan will work just fine for me.



CR,

I came to the same conclusion several years back, but lack the wherewithall to pull off what you're doing. I don't know if you're interested in putting another module together, but I'd be interested if you are.

thanks,

Jim



If I could get 5-10 people, I just might. If I do, I'll let you know.

[image: View Post]spud786, on 30 May 2010 - 11:59 PM, said:

Yeh , whats the problem, The bike is designed to keep the heat off the rider and the cooling system does that very well .

The bike works as its supposed too, keeps the heat off the rider , Id rather have a warmer running engine than hot legs. I also ride in high heat post 100, the bike holds up great in stopped trafic the fan is extremely effective. I dont understand all the heat issue complaints at all.

so now your bike is cooler but you have to wear fire proof clothes, thats Funny!


Yeah, when the bike belches out all the coolant and you are stuck at the side of the road waiting for it to cool down and either have to find some coolant and refill it (after pulling off the bodywork) -or call a truck to come tow you.

But at least you can wear your shorts and flip-flops instead of proper ATGATT...

Works like it is supposed to! :cheerleader:

[image: View Post]Serenity_VFR, on 31 May 2010 - 06:21 AM, said:

[image: View Post]spud786, on 30 May 2010 - 11:59 PM, said:

Yeh , whats the problem, The bike is designed to keep the heat off the rider and the cooling system does that very well .

The bike works as its supposed too, keeps the heat off the rider , Id rather have a warmer running engine than hot legs. I also ride in high heat post 100, the bike holds up great in stopped trafic the fan is extremely effective. I dont understand all the heat issue complaints at all.

so now your bike is cooler but you have to wear fire proof clothes, thats Funny!


Yeah, when the bike belches out all the coolant and you are stuck at the side of the road waiting for it to cool down and either have to find some coolant and refill it (after pulling off the bodywork) -or call a truck to come tow you.

But at least you can wear your shorts and flip-flops instead of proper ATGATT...

Works like it is supposed to! :cheerleader:


My Y2K with 30K miles had no problems with cooling. Fan would come on around 218-220 and drop temps back to the low 200's. Never saw temps over 230. Once up to speed, temp dropped dramatically to running around 185. So...I had a tip over on the clutch side in the garage, nothing broke but it was on its side for several minutes while I collected myself and got it back on the side-stand. Now I heat up much faster and run hotter 210-225 (about 20 degrees) than before. I'm thinking air in the lines/system so I will change coolant this week and bleed the system as per manual and will go from there. Just an interesting side bar since I had no cooling issues before the tip-over.

[image: View Post]Serenity_VFR, on 31 May 2010 - 06:21 AM, said:

[image: View Post]spud786, on 30 May 2010 - 11:59 PM, said:

Yeh , whats the problem, The bike is designed to keep the heat off the rider and the cooling system does that very well .

The bike works as its supposed too, keeps the heat off the rider , Id rather have a warmer running engine than hot legs. I also ride in high heat post 100, the bike holds up great in stopped trafic the fan is extremely effective. I dont understand all the heat issue complaints at all.

so now your bike is cooler but you have to wear fire proof clothes, thats Funny!


Yeah, when the bike belches out all the coolant and you are stuck at the side of the road waiting for it to cool down and either have to find some coolant and refill it (after pulling off the bodywork) -or call a truck to come tow you.

But at least you can wear your shorts and flip-flops instead of proper ATGATT...

Works like it is supposed to! Posted Image



I never seen that happen on my 06 at all, I still say Honda's coolant is causing issues with metals in the VFR system, like the thermo. and then there are the water wetter guys, which it cant handle over 200 degree temps.

I can just tell you I have no cooling issue at all, never have on the vfr

I dumped that stuff when new to prestone mixes with anything 60 to 70 mix, I am in south texas, so it sees alot of heat

FYI.. my 2000 RC51/ SP1 had a single fan on the left side.. I think the twin fans were 02 and newer RC's only but I'm not 100% sure. I am 100% sure my 2000 RC had only 1 fan and it was stock. It ran just as hot as my VFR.. I personally haven't seen the temp on my VFR get higher than 232 deg but that's dangerously close to overheating IMO. I leave my gauges set to show my temp at all times becuase it at least gives me a chance to save the motor if it does get too hot. I plan to shut my bike down if I ever see the temp hit 236. I've been thinking about doing the VTR fan swap but I'm not totally convinced it will work. It makes sense to me but I do find myself sitting at long red lights around here. If the hawk fan doesn't work well when stopped, it may not help.

[image: View Post]spud786, on 30 May 2010 - 11:59 PM, said:

Yeh , whats the problem, The bike is designed to keep the heat off the rider and the cooling system does that very well .

The bike works as its supposed too, keeps the heat off the rider , Id rather have a warmer running engine than hot legs. I also ride in high heat post 100, the bike holds up great in stopped trafic the fan is extremely effective. I dont understand all the heat issue complaints at all.

so now your bike is cooler but you have to wear fire proof clothes, thats Funny!

Okay you live in texas so I get that you see hot days,
But how long are you in stopped traffic, and what is the heat index behind that city bus at rush hour.
As for heat on my leg, heat on the outside of one leg beats feeling the heat off the frame/tank/bars/seat roast most of the tender parts while in stopped or creeping traffic.
Then, if you really are luck and the traffic breaks up before the bike boils but doesn't get back to full speed, you get to roll along with the 240+ temps not changing because the fan is bucking the normal and natural airflow pattern. Even if some miracle happens and the traffic suddenly disappears in front of you, its miles before the bike cools down enough to shut down the fan and really cool off.
I meant think about this if while you are moving with the fan off the bike consistently cools to say 190, but in a traffic jam the fan starts running and the temperature after 15 minutes is 240 and climbing, plus when the jam ends and your riding at 40 mph with the fan running it doesn't cool back down for miles. It cools painfully slow until you get down to 210 where the fan kicks off and in less than a minute your back at 190..
What more proof do you need that the fan design is flawed.
I mean Codewriter agrees that the fan design is flawed, he just thinks that there is a different solution to the problem (he wants to switch it off as soon as there is some natural airflow through the bike from the front). I think that having the fan supplement the natural airflow when stopped and at low speeds better than having it fight nature.

Thanks but no thanks, I'd rather have one slightly warm leg versus baked thighs, groin, abdomen, chest and one boiled VFR motor. I know that my own core temp stays lower when the sh fan blade is running even though I can feel the heat on left calf. So the bike and rider are cooler in the end as the VTR fan pushed the heat out of the bike, instead of trying to hold it in.

[image: View Post]Smokey74, on 31 May 2010 - 07:36 PM, said:

FYI.. my 2000 RC51/ SP1 had a single fan on the left side.. I think the twin fans were 02 and newer RC's only but I'm not 100% sure. I am 100% sure my 2000 RC had only 1 fan and it was stock. It ran just as hot as my VFR.. I personally haven't seen the temp on my VFR get higher than 232 deg but that's dangerously close to overheating IMO. I leave my gauges set to show my temp at all times becuase it at least gives me a chance to save the motor if it does get too hot. I plan to shut my bike down if I ever see the temp hit 236. I've been thinking about doing the VTR fan swap but I'm not totally convinced it will work. It makes sense to me but I do find myself sitting at long red lights around here. If the hawk fan doesn't work well when stopped, it may not help.

I think that the sp1's did only have a single fan, and the sp2's got two. It doesn't matter two fans trying to blow air the wrong way doesn't work any better than one fan blowing it in instead of out.
As for the super hawk fan working or not, I can only tell you this.
For me it works and I did have issues from the day I bought the VFR until the day I yanked out that VFR fan blade, Now I have none.
To me that tells me that it did not matter what condition my coolant was in or what type I was using. It did not matter what the local conditions were particularly.
The heating issue was there until I swapped out the fan.

Also after I figured out how to reverse the airflow on the RC51, It also cools just fine moving or standing still now

What I would love is to have two bikes brought together, checked on a reasonably cool day for temperatures after idling and while waiting in traffic.
then swap out the fan blade on the hotter running of the two bikes and repeat the test on a nice 95+ degree day at rush hour.
I'd bet that the unchanged bike has cooling issues, both while stopped and while slowly moving. I'll even bet that when they both get an opportunity to run faster, the unchanged bike can't cool down as quickly as the Hawk fanned bike.

In fact it's like this, your not that far away.
Order the fan. If you want I'll ride out and help you install it. If Your not happy, after trying out, I'll buy the superhawk fan from you.
That is how much I'm convinced that it works.

[image: View Post]JES_VFR, on 01 June 2010 - 01:37 AM, said:

[image: View Post]spud786, on 30 May 2010 - 11:59 PM, said:

Yeh , whats the problem, The bike is designed to keep the heat off the rider and the cooling system does that very well .

The bike works as its supposed too, keeps the heat off the rider , Id rather have a warmer running engine than hot legs. I also ride in high heat post 100, the bike holds up great in stopped trafic the fan is extremely effective. I dont understand all the heat issue complaints at all.

so now your bike is cooler but you have to wear fire proof clothes, thats Funny!

Okay you live in texas so I get that you see hot days,
But how long are you in stopped traffic, and what is the heat index behind that city bus at rush hour.
As for heat on my leg, heat on the outside of one leg beats feeling the heat off the frame/tank/bars/seat roast most of the tender parts while in stopped or creeping traffic.
Then, if you really are luck and the traffic breaks up before the bike boils but doesn't get back to full speed, you get to roll along with the 240+ temps not changing because the fan is bucking the normal and natural airflow pattern. Even if some miracle happens and the traffic suddenly disappears in front of you, its miles before the bike cools down enough to shut down the fan and really cool off.
I meant think about this if while you are moving with the fan off the bike consistently cools to say 190, but in a traffic jam the fan starts running and the temperature after 15 minutes is 240 and climbing, plus when the jam ends and your riding at 40 mph with the fan running it doesn't cool back down for miles. It cools painfully slow until you get down to 210 where the fan kicks off and in less than a minute your back at 190..
What more proof do you need that the fan design is flawed.
I mean Codewriter agrees that the fan design is flawed, he just thinks that there is a different solution to the problem (he wants to switch it off as soon as there is some natural airflow through the bike from the front). I think that having the fan supplement the natural airflow when stopped and at low speeds better than having it fight nature.

Thanks but no thanks, I'd rather have one slightly warm leg versus baked thighs, groin, abdomen, chest and one boiled VFR motor. I know that my own core temp stays lower when the sh fan blade is running even though I can feel the heat on left calf. So the bike and rider are cooler in the end as the VTR fan pushed the heat out of the bike, instead of trying to hold it in.

[image: View Post]Smokey74, on 31 May 2010 - 07:36 PM, said:

FYI.. my 2000 RC51/ SP1 had a single fan on the left side.. I think the twin fans were 02 and newer RC's only but I'm not 100% sure. I am 100% sure my 2000 RC had only 1 fan and it was stock. It ran just as hot as my VFR.. I personally haven't seen the temp on my VFR get higher than 232 deg but that's dangerously close to overheating IMO. I leave my gauges set to show my temp at all times becuase it at least gives me a chance to save the motor if it does get too hot. I plan to shut my bike down if I ever see the temp hit 236. I've been thinking about doing the VTR fan swap but I'm not totally convinced it will work. It makes sense to me but I do find myself sitting at long red lights around here. If the hawk fan doesn't work well when stopped, it may not help.

I think that the sp1's did only have a single fan, and the sp2's got two. It doesn't matter two fans trying to blow air the wrong way doesn't work any better than one fan blowing it in instead of out.
As for the super hawk fan working or not, I can only tell you this.
For me it works and I did have issues from the day I bought the VFR until the day I yanked out that VFR fan blade, Now I have none.
To me that tells me that it did not matter what condition my coolant was in or what type I was using. It did not matter what the local conditions were particularly.
The heating issue was there until I swapped out the fan.

Also after I figured out how to reverse the airflow on the RC51, It also cools just fine moving or standing still now

What I would love is to have two bikes brought together, checked on a reasonably cool day for temperatures after idling and while waiting in traffic.
then swap out the fan blade on the hotter running of the two bikes and repeat the test on a nice 95+ degree day at rush hour.
I'd bet that the unchanged bike has cooling issues, both while stopped and while slowly moving. I'll even bet that when they both get an opportunity to run faster, the unchanged bike can't cool down as quickly as the Hawk fanned bike.

In fact it's like this, your not that far away.
Order the fan. If you want I'll ride out and help you install it. If Your not happy, after trying out, I'll buy the superhawk fan from you.
That is how much I'm convinced that it works.




If your that confident, I'll give it a try. Thanks for your help. I'm sure I can handle the swap myself but your welcome to come out and check my results first hand. I've got some great mountian twisties we can hit afterwards.

[image: View Post]Smokey74, on 01 June 2010 - 12:47 PM, said:

If your that confident, I'll give it a try. Thanks for your help. I'm sure I can handle the swap myself but your welcome to come out and check my results first hand. I've got some great mountian twisties we can hit afterwards.


that sounds pretty good, You are getting it the mountains up there.
I'm getting pretty stir crazy right now with the hurry up, so you can wait, routine right now.
It was old at least three weeks ago and now it's disgusting.

[image: View Post]mello dude, on 26 August 2009 - 08:15 PM, said:

[image: View Post]coderighter, on Aug 26 2009, 09:00 PM, said:

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.

Why not just stick in the VTR Fan?
http://www.vfrdiscussion.com/forum/index.p...mp;#entry640043

MD



Because at a stop light, the VTR fan pulls preheated air from the 'engine compartment' and pushes it through the radiator. You get a much better cooling effect when you take air that's 60-80 degrees cooler from 'outside' the bike and push it through the radiator. The stock fan will cool better at a stop light than a VTR fan. Even people that have done the swap will tell you that the VTR fan doesn't cool as well as the stock fan when the bike is stopped. A VTR fan will cool better when moving for 1 reason, it's pushing air in the same direction as the air flow caused by the bike's forward progress. It's not really that it's adding any air flow, but more important, it's not blocking it by trying to push air the wrong way.

In theroy, if the bike never stopped, the fan would never be needed.

If you're in Texas on the highway, with the temp greater than fan trip speed, than it's stuck there because the stock fan is 'blocking' the air to the left radiator. If you could turn that fan off, you would again have use of both radiators and the temp would go down.

The stock fan works better at a stand still. VTR fan works better moving. No fan, no matter the direction of rotation, is going to help above 30 mph as the air flow caused by the bikes forward progress should, at that point, be greater than that of even the great VTR fan. A fan pushing air against air flow (caused by speeds above 30 mph) will hurt cooling. How much time do you spend between 1-30 mph? If you just stopped the fan, and stopped trying to block air flow above 30 mph, wouldn't you have the best of both worlds?

[image: View Post]JES_VFR, on 01 June 2010 - 08:07 PM, said:

[image: View Post]Smokey74, on 01 June 2010 - 12:47 PM, said:

If your that confident, I'll give it a try. Thanks for your help. I'm sure I can handle the swap myself but your welcome to come out and check my results first hand. I've got some great mountian twisties we can hit afterwards.


that sounds pretty good, You are getting it the mountains up there.
I'm getting pretty stir crazy right now with the hurry up, so you can wait, routine right now.
It was old at least three weeks ago and now it's disgusting.




Shoot me a PM if you wana come out my way and ride this Saturday. There's another member on here from NJ (Trav72) that might be comming out as well.

[image: View Post]coderighter, on 01 June 2010 - 11:08 PM, said:

[image: View Post]mello dude, on 26 August 2009 - 08:15 PM, said:

[image: View Post]coderighter, on Aug 26 2009, 09:00 PM, said:

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.

Why not just stick in the VTR Fan?
http://www.vfrdiscussion.com/forum/index.p...mp;#entry640043

MD



Because at a stop light, the VTR fan pulls preheated air from the 'engine compartment' and pushes it through the radiator. You get a much better cooling effect when you take air that's 60-80 degrees cooler from 'outside' the bike and push it through the radiator. The stock fan will cool better at a stop light than a VTR fan. Even people that have done the swap will tell you that the VTR fan doesn't cool as well as the stock fan when the bike is stopped. A VTR fan will cool better when moving for 1 reason, it's pushing air in the same direction as the air flow caused by the bike's forward progress. It's not really that it's adding any air flow, but more important, it's not blocking it by trying to push air the wrong way.

In theroy, if the bike never stopped, the fan would never be needed.

If you're in Texas on the highway, with the temp greater than fan trip speed, than it's stuck there because the stock fan is 'blocking' the air to the left radiator. If you could turn that fan off, you would again have use of both radiators and the temp would go down.

The stock fan works better at a stand still. VTR fan works better moving. No fan, no matter the direction of rotation, is going to help above 30 mph as the air flow caused by the bikes forward progress should, at that point, be greater than that of even the great VTR fan. A fan pushing air against air flow (caused by speeds above 30 mph) will hurt cooling. How much time do you spend between 1-30 mph? If you just stopped the fan, and stopped trying to block air flow above 30 mph, wouldn't you have the best of both worlds?


For the sake of splitting hairs and discussion, I agree that the stocker fan would cool better at a total stop. I'm not sure I agree about your 30mph number when the fan is becoming ineffective against the incoming air from the front. I think its more in the 10 -15 mph range and why I did the VTR switch. Admittedly, for either one of us it's conjecture what the true number is unless we stick the bike in a wind tunnel of sorts and generate data. Which then comes to another goofy point is Honda has the puller and pusher fans in several bikes, maybe they dont understand it either.

-This will be my first full summer with the VTR, so we'll see how it goes for a data point. (I still have the stocker hanging on the wall.) Cheers :beer:

[image: View Post]coderighter, on 01 June 2010 - 11:08 PM, said:

Because at a stop light, the VTR fan pulls preheated air from the 'engine compartment' and pushes it through the radiator. You get a much better cooling effect when you take air that's 60-80 degrees cooler from 'outside' the bike and push it through the radiator. The stock fan will cool better at a stop light than a VTR fan. Even people that have done the swap will tell you that the VTR fan doesn't cool as well as the stock fan when the bike is stopped. A VTR fan will cool better when moving for 1 reason, it's pushing air in the same direction as the air flow caused by the bike's forward progress. It's not really that it's adding any air flow, but more important, it's not blocking it by trying to push air the wrong way.

In theroy, if the bike never stopped, the fan would never be needed.

If you're in Texas on the highway, with the temp greater than fan trip speed, than it's stuck there because the stock fan is 'blocking' the air to the left radiator. If you could turn that fan off, you would again have use of both radiators and the temp would go down.

The stock fan works better at a stand still. VTR fan works better moving. No fan, no matter the direction of rotation, is going to help above 30 mph as the air flow caused by the bikes forward progress should, at that point, be greater than that of even the great VTR fan. A fan pushing air against air flow (caused by speeds above 30 mph) will hurt cooling. How much time do you spend between 1-30 mph? If you just stopped the fan, and stopped trying to block air flow above 30 mph, wouldn't you have the best of both worlds?


I disagree with your saying that the Stock fan works better than the VTR fan when the bike is standing still. Its does not. My fifth gen would just get warmer and warmer if it was sitting idling in the driveway too long with the stock fan. The fan might actually move enough heat around once or twice to cool the bike enough to cycle off, but it would only do it once or twice, then the fan would run continuously and the bike would just keep heating up.
Now the VTR fan kicks in and cycles maybe 17-18 times in a half an hour, but the temp is never above the 223-224 that the fan kicks on at.

Yes the fan pulls from in front of the bike and that means that it gets heat off the exhaust and engine before it gets to the rads, but with VTR fan the heat gets pushed out of the bike. A few seconds after the fan has kicked on the temp is coming down and the momentary blast of heat from the left side vent has lessened.

The stock fan sucks cool air in through the rad and then dump this heated air the engine bay, the heat doesn't travel anywhere really and just warms the entire bike, in an escalating cycle until the display is flashing to get you attention of the impending overheating. To me that just proves that the Stock fan is a turd.

Any you are right no fan that size is going to make a significant contribution to cooling if the bike is traveling faster than 30 mph.
But the point is that the stock fan is a poor design even when the bike is stopped. Keeping heat in the bike is not effective cooling.

I'd rather spend an extra 15-20 seconds moving preheated air out of the bike, than just continuing to pump the heat around the bike.

The absolute best of both worlds would be the pusher vtr fan and ducting that keeps the header and block heated air entirely away from the radiators.
But those ducts are a project full of time and money that I don't have right now, maybe someday when I find someone that will, like there are people that will make those ducts for the rc51's.

[image: View Post]enzed_viffer, on 29 May 2010 - 12:31 AM, said:

My experience is that when I'm riding in traffic, the temperature will gradually creep up, because the column of traffic entrains the air, so instead of there being a positive pressure in front of the engine and low pressure either side of the bike, there's little air movement. Once the traffic's doing more than say 40mph, that changes. This is worse in summer than winter. On the open road, I've never had problems with the bike getting hot.
I fitted a manual switch that I trigger whenever I'm stationary and the temperature gets above about 90C. Originally I was going to fit another thermoswitch that I found that was set to go on at 95 and off at 85C (IIRC). I decided against this, as there would be too many times when it would be on and I'd be moving. So far, apart from forgetting to turn it off, the manual switch has worked out well. I may add a red light on the dash to remind me to turn it off.



To me this sounds like the most simple and effective way to handle the heat issue.. :fing02: One question though.. are you running the stock fan or the superhawk fan?? I've even thought about just leaving the stock fan alone and adding a Superhawk fan to the right side hooked to a switch so I can cool it as needed. If there's no space for the fan on the inside, I wouldn't mind trimming the fairing and mounting it on the outside if it works. I'm more concerned about function over form with this bike.

[image: View Post]Smokey74, on 04 June 2010 - 09:02 PM, said:

[image: View Post]enzed_viffer, on 29 May 2010 - 12:31 AM, said:

My experience is that when I'm riding in traffic, the temperature will gradually creep up, because the column of traffic entrains the air, so instead of there being a positive pressure in front of the engine and low pressure either side of the bike, there's little air movement. Once the traffic's doing more than say 40mph, that changes. This is worse in summer than winter. On the open road, I've never had problems with the bike getting hot.
I fitted a manual switch that I trigger whenever I'm stationary and the temperature gets above about 90C. Originally I was going to fit another thermoswitch that I found that was set to go on at 95 and off at 85C (IIRC). I decided against this, as there would be too many times when it would be on and I'd be moving. So far, apart from forgetting to turn it off, the manual switch has worked out well. I may add a red light on the dash to remind me to turn it off.


To me this sounds like the most simple and effective way to handle the heat issue.. :fing02: One question though.. are you running the stock fan or the superhawk fan?? I've even thought about just leaving the stock fan alone and adding a Superhawk fan to the right side hooked to a switch so I can cool it as needed. If there's no space for the fan on the inside, I wouldn't mind trimming the fairing and mounting it on the outside if it works. I'm more concerned about function over form with this bike.


IIRC Ian is running the stock fan.
And his argument holds water. You don't want you fan to try to work against the natural flow, You want it to be there to substitute for the natural flow then the vehicle is stopped or not really moving.

You'd have to hack that fairing up pretty bad to get enough room for a fan in there. Even if you hung the radiator out on spacers, there isn't going to be a lot room to fit any fan on either side.
I keep thinking about adding some heat baffles to both sides. Just a piece of aluminum sheet with ceramic barrier paint on both sides installed between the block headers and the radiators, That would further cut down on the heating of the air going to the rads from inside the bike, but it would only work for someone using the pusher fan (superhawk fan blade).
It also would probably mean a custom V fairing piece with quite a few more vents, out rear the lowers to get cool air away from the headers in the first place,

Sort of poorman's rad ducting.

[image: View Post]JES_VFR, on 04 June 2010 - 08:36 PM, said:

[image: View Post]coderighter, on 01 June 2010 - 11:08 PM, said:

Because at a stop light, the VTR fan pulls preheated air from the 'engine compartment' and pushes it through the radiator. You get a much better cooling effect when you take air that's 60-80 degrees cooler from 'outside' the bike and push it through the radiator. The stock fan will cool better at a stop light than a VTR fan. Even people that have done the swap will tell you that the VTR fan doesn't cool as well as the stock fan when the bike is stopped. A VTR fan will cool better when moving for 1 reason, it's pushing air in the same direction as the air flow caused by the bike's forward progress. It's not really that it's adding any air flow, but more important, it's not blocking it by trying to push air the wrong way.

In theroy, if the bike never stopped, the fan would never be needed.

If you're in Texas on the highway, with the temp greater than fan trip speed, than it's stuck there because the stock fan is 'blocking' the air to the left radiator. If you could turn that fan off, you would again have use of both radiators and the temp would go down.

The stock fan works better at a stand still. VTR fan works better moving. No fan, no matter the direction of rotation, is going to help above 30 mph as the air flow caused by the bikes forward progress should, at that point, be greater than that of even the great VTR fan. A fan pushing air against air flow (caused by speeds above 30 mph) will hurt cooling. How much time do you spend between 1-30 mph? If you just stopped the fan, and stopped trying to block air flow above 30 mph, wouldn't you have the best of both worlds?


I disagree with your saying that the Stock fan works better than the VTR fan when the bike is standing still. Its does not. My fifth gen would just get warmer and warmer if it was sitting idling in the driveway too long with the stock fan. The fan might actually move enough heat around once or twice to cool the bike enough to cycle off, but it would only do it once or twice, then the fan would run continuously and the bike would just keep heating up.
Now the VTR fan kicks in and cycles maybe 17-18 times in a half an hour, but the temp is never above the 223-224 that the fan kicks on at.

Yes the fan pulls from in front of the bike and that means that it gets heat off the exhaust and engine before it gets to the rads, but with VTR fan the heat gets pushed out of the bike. A few seconds after the fan has kicked on the temp is coming down and the momentary blast of heat from the left side vent has lessened.

The stock fan sucks cool air in through the rad and then dump this heated air the engine bay, the heat doesn't travel anywhere really and just warms the entire bike, in an escalating cycle until the display is flashing to get you attention of the impending overheating. To me that just proves that the Stock fan is a turd.

Any you are right no fan that size is going to make a significant contribution to cooling if the bike is traveling faster than 30 mph.
But the point is that the stock fan is a poor design even when the bike is stopped. Keeping heat in the bike is not effective cooling.

I'd rather spend an extra 15-20 seconds moving preheated air out of the bike, than just continuing to pump the heat around the bike.

The absolute best of both worlds would be the pusher vtr fan and ducting that keeps the header and block heated air entirely away from the radiators.
But those ducts are a project full of time and money that I don't have right now, maybe someday when I find someone that will, like there are people that will make those ducts for the rc51's.


Strange, sitting at a long light, if the bike gets to 220, the fan kicks on. The temps immediately start to drop. With in a minute or two the temp hits 210 the fan turns off. I never have a problem stopped. The highest temp I've ever seen stopped is 221 and that was a 100+ degree day in eastern Washington. I'm not sure why you had such a issue with yours. The only time I have problem is if the light turn green while the fan is still running.

I've never experienced the hideous heat vortex of which you speak. However bear in mind if the fan not running, the R/R could be dumping more current, making the frame hotter. It sounds like your fan runs alot more than mine.

By turning fan into a pusher, you lower the efficiency of the fan by 20%, even with the correct fan blades.

http://www.perma-coo...Cat_page16.html

Not only are you pushing hot air across the radiator, you're also pushing about 20% less CFM.

[image: View Post]coderighter, on 05 June 2010 - 02:36 AM, said:

[image: View Post]JES_VFR, on 04 June 2010 - 08:36 PM, said:

I disagree with your saying that the Stock fan works better than the VTR fan when the bike is standing still. Its does not. My fifth gen would just get warmer and warmer if it was sitting idling in the driveway too long with the stock fan. The fan might actually move enough heat around once or twice to cool the bike enough to cycle off, but it would only do it once or twice, then the fan would run continuously and the bike would just keep heating up.
Now the VTR fan kicks in and cycles maybe 17-18 times in a half an hour, but the temp is never above the 223-224 that the fan kicks on at.

Yes the fan pulls from in front of the bike and that means that it gets heat off the exhaust and engine before it gets to the rads, but with VTR fan the heat gets pushed out of the bike. A few seconds after the fan has kicked on the temp is coming down and the momentary blast of heat from the left side vent has lessened.

The stock fan sucks cool air in through the rad and then dump this heated air the engine bay, the heat doesn't travel anywhere really and just warms the entire bike, in an escalating cycle until the display is flashing to get you attention of the impending overheating. To me that just proves that the Stock fan is a turd.

Any you are right no fan that size is going to make a significant contribution to cooling if the bike is traveling faster than 30 mph.
But the point is that the stock fan is a poor design even when the bike is stopped. Keeping heat in the bike is not effective cooling.

I'd rather spend an extra 15-20 seconds moving preheated air out of the bike, than just continuing to pump the heat around the bike.

The absolute best of both worlds would be the pusher vtr fan and ducting that keeps the header and block heated air entirely away from the radiators.
But those ducts are a project full of time and money that I don't have right now, maybe someday when I find someone that will, like there are people that will make those ducts for the rc51's.


Strange, sitting at a long light, if the bike gets to 220, the fan kicks on. The temps immediately start to drop. With in a minute or two the temp hits 210 the fan turns off. I never have a problem stopped. The highest temp I've ever seen stopped is 221 and that was a 100+ degree day in eastern Washington. I'm not sure why you had such a issue with yours. The only time I have problem is if the light turn green while the fan is still running.

I've never experienced the hideous heat vortex of which you speak. However bear in mind if the fan not running, the R/R could be dumping more current, making the frame hotter. It sounds like your fan runs alot more than mine.

By turning fan into a pusher, you lower the efficiency of the fan by 20%, even with the correct fan blades.

http://www.perma-coo...Cat_page16.html

Not only are you pushing hot air across the radiator, you're also pushing about 20% less CFM.


I know that a pusher fan is less efficient than a tractor fan, unless is it's total surface is larger than the total surface of the radiator its has a complete shrouding duct.
But the simple facts are these.
when I had the stock fan blade and I came to a stop on a day like today (the high at 12:45 was 90f out in the open, the heat in traffic was 96f on the cars outside thermometer, and with 55% humidity the heat index was 112.).
Temp would rise to 224 and the fan would kick on, and in 2 or 3 minutes it would have cooled down to 213-214 and the fan would shut off. As soon as the temperature would shut off the temp would start climbing again and in two minutes or so would be right back to 224. The fan would kick on for 5 or 6 minutes this time before it could get the temp down to 213-214 and cycle off. In about a minute (maybe minute and half) the temp would be back to 223 and fan would again come on. From here on the fan would run continuously (with the temp never really coming down), until either I got the bike moving at 30+ mph and clear of the traffic -or- it when past 238, at which point I'd shut off the damn thing, paddle foot it to the side of the road and wait for it to cool off (usually just in time to see the traffic jam start to move).

But since I put the VTR fan on the bike, I never have this problem.
Coolant temp gets to 223, fan kicks on. temp starts to drop. A couple of minutes go by temp drips to 213, fan kicks off. Minutes go by and temp creeps back up to 223, fan kicks on again, temp drops to 213 in a few minutes and fan cycles off.
This cycle will repeat for at least half an hour without the temp climbing above 223 or the fan reaching a state where it can't cool enough to cycle on/off. The on cycles don't appreciatively longer unless the ambient temp also rising (like when you are sitting in that concrete canyon called Vine st in Philly in the noon day sun, where the outside temperature climbs as you watch!) so I'd say that in practice the superhawk fan is much more effective than the stock fan ever was. Tractor vs pusher fan, drawing air through the bike or not, It just plain works a world better in that concrete oven than the oem fan ever did.

I've seen lots of post describing the same behavior from lots of people on the other VFR Lists so I know it is not just me and my VFR. In fact one of the big disappointments was that Honda supposedly fixed the heating issues with the Vtec editions, yet all through the summer's of 2002 and 2003 there were people complaining about their near meltdowns in high heat and traffic.
I'm sorry Jon, but to me these people that have had issues and those that are just concerned with it now can't all be sniffing vapors, there is a problem with the fan when the bike is standing still.
I don't care if you fill your system with "Pink" or 'limeade", that oem fan is not going to keep the bike down to reasonable temperatures for long when you meet the right conditions.

Now I'm not saying that the superhawk fan blade is the ultimate solution to having the VFR keep it's cool.
I'm just saying that it does a damn sight better than the crap design from Honda. That it is Honda part (so its not some unobtainium part from some rocket manufacturer). Its simple to try and in the end very cost effective.
I haven't heard of anyone saying that it did not work better than the stock fan.

I had the same problem with my RC51, cooking off in the heat from the day I got it. God I wish the solution had been as easy as just swapping a couple of VTR fan blades. In the end, I flipped the stock fan blades over with a little work and reversed the motors, all to try and get close to an efficient pusher fan operation. Even with all the flaws (not a pusher fan blade design, not ducted, drawing air from around the motor and header, less efficient as a pusher over a tractor fan, etc..), again the fans work, the bike doesn't overheat anymore and flatten the battery. I know that when time and funds allow I'll be back to this with carbon fiber ducts, spal fans and some sort of variable fan control system. Come to think of it I'll probably be at the VFR first with these things or at least some other heat management measures.

Honda did us a major dis-service with both these bikes as neither one has an excess of cooling "power" built into it.
Both want to run hot as per external laws, but they certainly need some system improvements.




Jon, I'd bet you that if you tried the superhawk fan, you would suddenly realize that you don't need the control module to switch off the fan when you get moving.

[image: View Post]JES_VFR, on 05 June 2010 - 04:08 PM, said:

[image: View Post]coderighter, on 05 June 2010 - 02:36 AM, said:

[image: View Post]JES_VFR, on 04 June 2010 - 08:36 PM, said:

I disagree with your saying that the Stock fan works better than the VTR fan when the bike is standing still. Its does not. My fifth gen would just get warmer and warmer if it was sitting idling in the driveway too long with the stock fan. The fan might actually move enough heat around once or twice to cool the bike enough to cycle off, but it would only do it once or twice, then the fan would run continuously and the bike would just keep heating up.
Now the VTR fan kicks in and cycles maybe 17-18 times in a half an hour, but the temp is never above the 223-224 that the fan kicks on at.

Yes the fan pulls from in front of the bike and that means that it gets heat off the exhaust and engine before it gets to the rads, but with VTR fan the heat gets pushed out of the bike. A few seconds after the fan has kicked on the temp is coming down and the momentary blast of heat from the left side vent has lessened.

The stock fan sucks cool air in through the rad and then dump this heated air the engine bay, the heat doesn't travel anywhere really and just warms the entire bike, in an escalating cycle until the display is flashing to get you attention of the impending overheating. To me that just proves that the Stock fan is a turd.

Any you are right no fan that size is going to make a significant contribution to cooling if the bike is traveling faster than 30 mph.
But the point is that the stock fan is a poor design even when the bike is stopped. Keeping heat in the bike is not effective cooling.

I'd rather spend an extra 15-20 seconds moving preheated air out of the bike, than just continuing to pump the heat around the bike.

The absolute best of both worlds would be the pusher vtr fan and ducting that keeps the header and block heated air entirely away from the radiators.
But those ducts are a project full of time and money that I don't have right now, maybe someday when I find someone that will, like there are people that will make those ducts for the rc51's.


Strange, sitting at a long light, if the bike gets to 220, the fan kicks on. The temps immediately start to drop. With in a minute or two the temp hits 210 the fan turns off. I never have a problem stopped. The highest temp I've ever seen stopped is 221 and that was a 100+ degree day in eastern Washington. I'm not sure why you had such a issue with yours. The only time I have problem is if the light turn green while the fan is still running.

I've never experienced the hideous heat vortex of which you speak. However bear in mind if the fan not running, the R/R could be dumping more current, making the frame hotter. It sounds like your fan runs alot more than mine.

By turning fan into a pusher, you lower the efficiency of the fan by 20%, even with the correct fan blades.

http://www.perma-coo...Cat_page16.html

Not only are you pushing hot air across the radiator, you're also pushing about 20% less CFM.


I know that a pusher fan is less efficient than a tractor fan, unless is it's total surface is larger than the total surface of the radiator its has a complete shrouding duct.
But the simple facts are these.
when I had the stock fan blade and I came to a stop on a day like today (the high at 12:45 was 90f out in the open, the heat in traffic was 96f on the cars outside thermometer, and with 55% humidity the heat index was 112.).
Temp would rise to 224 and the fan would kick on, and in 2 or 3 minutes it would have cooled down to 213-214 and the fan would shut off. As soon as the temperature would shut off the temp would start climbing again and in two minutes or so would be right back to 224. The fan would kick on for 5 or 6 minutes this time before it could get the temp down to 213-214 and cycle off. In about a minute (maybe minute and half) the temp would be back to 223 and fan would again come on. From here on the fan would run continuously (with the temp never really coming down), until either I got the bike moving at 30+ mph and clear of the traffic -or- it when past 238, at which point I'd shut off the damn thing, paddle foot it to the side of the road and wait for it to cool off (usually just in time to see the traffic jam start to move).

But since I put the VTR fan on the bike, I never have this problem.
Coolant temp gets to 223, fan kicks on. temp starts to drop. A couple of minutes go by temp drips to 213, fan kicks off. Minutes go by and temp creeps back up to 223, fan kicks on again, temp drops to 213 in a few minutes and fan cycles off.
This cycle will repeat for at least half an hour without the temp climbing above 223 or the fan reaching a state where it can't cool enough to cycle on/off. The on cycles don't appreciatively longer unless the ambient temp also rising (like when you are sitting in that concrete canyon called Vine st in Philly in the noon day sun, where the outside temperature climbs as you watch!) so I'd say that in practice the superhawk fan is much more effective than the stock fan ever was. Tractor vs pusher fan, drawing air through the bike or not, It just plain works a world better in that concrete oven than the oem fan ever did.

I've seen lots of post describing the same behavior from lots of people on the other VFR Lists so I know it is not just me and my VFR. In fact one of the big disappointments was that Honda supposedly fixed the heating issues with the Vtec editions, yet all through the summer's of 2002 and 2003 there were people complaining about their near meltdowns in high heat and traffic.
I'm sorry Jon, but to me these people that have had issues and those that are just concerned with it now can't all be sniffing vapors, there is a problem with the fan when the bike is standing still.
I don't care if you fill your system with "Pink" or 'limeade", that oem fan is not going to keep the bike down to reasonable temperatures for long when you meet the right conditions.

Now I'm not saying that the superhawk fan blade is the ultimate solution to having the VFR keep it's cool.
I'm just saying that it does a damn sight better than the crap design from Honda. That it is Honda part (so its not some unobtainium part from some rocket manufacturer). Its simple to try and in the end very cost effective.
I haven't heard of anyone saying that it did not work better than the stock fan.

I had the same problem with my RC51, cooking off in the heat from the day I got it. God I wish the solution had been as easy as just swapping a couple of VTR fan blades. In the end, I flipped the stock fan blades over with a little work and reversed the motors, all to try and get close to an efficient pusher fan operation. Even with all the flaws (not a pusher fan blade design, not ducted, drawing air from around the motor and header, less efficient as a pusher over a tractor fan, etc..), again the fans work, the bike doesn't overheat anymore and flatten the battery. I know that when time and funds allow I'll be back to this with carbon fiber ducts, spal fans and some sort of variable fan control system. Come to think of it I'll probably be at the VFR first with these things or at least some other heat management measures.

Honda did us a major dis-service with both these bikes as neither one has an excess of cooling "power" built into it.
Both want to run hot as per external laws, but they certainly need some system improvements.




Jon, I'd bet you that if you tried the superhawk fan, you would suddenly realize that you don't need the control module to switch off the fan when you get moving.


I do believe that with the VTR fan, you've seen improvement in your case. I believe the improvement is slow moving stop and go traffic, not stoplight to stoplight. As far as the VTR fan cooling better when stopped, I'm not buying it. There have been members who have made the switch and posted that while their stop and go traffic temps went down, their stop light temps increased.

We all agree, a pusher fan is only 80% efficient when compared to a puller fan. We also agree that the air in the tunnel is hotter than the air on the side of the bike, I measured a 67 degree difference earlier in this thread. Granted, once the fan starts the temp will come down, but it will never be as cold as the 'fresh' air on the side of the bike. When the bike is stopped, we can safely say the stock fan is the better choice.

We all agree that no fan helps above 30 mph(ish). We all agree that running a fan against the flow of air across a radiator is a bad thing.

I do see a big benefit to the VTR fan swap in the 10-30mph window. I believe, however, a large portion of the benefit is not so much that the VTR fan itself is aiding in cooling, but that you've removed the stock fan. Once the bike is in motion, the stock fan is fighting air flow caused by bike movement. Replacing the stock fan with the VTR fan just stops that fight.

The biggest reason for these bikes running hot, in most cases, is not the fan, but the A/F mixture. From the factory, they are so lean that they just make a ton of heat. Currently, I'm not running a fan control of any kind or a VTR fan, and my bike has no heat problems. Ever since I installed my PCV w/autotune, I've gotten rid of those lean spots and along with those went the high temps. I've found during the last couple rides, that I actually need to change my mapping a little because I'm having a problem with not enough heat. I couldn't get it over 172 on the freeway last Saturday.

All this fan talk is really just a band aid for a lean mixture (and too much/wrong antifreeze). If you really want to fix the problem, fix the mixture. Once you fix the mixture, you should be able to run which ever fan makes you feel better.

[image: View Post]coderighter, on 07 June 2010 - 12:56 PM, said:

I do believe that with the VTR fan, you've seen improvement in your case. I believe the improvement is slow moving stop and go traffic, not stoplight to stoplight. As far as the VTR fan cooling better when stopped, I'm not buying it. There have been members who have made the switch and posted that while their stop and go traffic temps went down, their stop light temps increased.

We all agree, a pusher fan is only 80% efficient when compared to a puller fan. We also agree that the air in the tunnel is hotter than the air on the side of the bike, I measured a 67 degree difference earlier in this thread. Granted, once the fan starts the temp will come down, but it will never be as cold as the 'fresh' air on the side of the bike. When the bike is stopped, we can safely say the stock fan is the better choice.

We all agree that no fan helps above 30 mph(ish). We all agree that running a fan against the flow of air across a radiator is a bad thing.

I do see a big benefit to the VTR fan swap in the 10-30mph window. I believe, however, a large portion of the benefit is not so much that the VTR fan itself is aiding in cooling, but that you've removed the stock fan. Once the bike is in motion, the stock fan is fighting air flow caused by bike movement. Replacing the stock fan with the VTR fan just stops that fight.

The biggest reason for these bikes running hot, in most cases, is not the fan, but the A/F mixture. From the factory, they are so lean that they just make a ton of heat. Currently, I'm not running a fan control of any kind or a VTR fan, and my bike has no heat problems. Ever since I installed my PCV w/autotune, I've gotten rid of those lean spots and along with those went the high temps. I've found during the last couple rides, that I actually need to change my mapping a little because I'm having a problem with not enough heat. I couldn't get it over 172 on the freeway last Saturday.

All this fan talk is really just a band aid for a lean mixture (and too much/wrong antifreeze). If you really want to fix the problem, fix the mixture. Once you fix the mixture, you should be able to run which ever fan makes you feel better.

Well, I think your right about the lean points and what it takes to really fix the tune.
I've still got to install autotune on my bike.

[image: View Post]JES_VFR, on 07 June 2010 - 05:46 PM, said:

[image: View Post]coderighter, on 07 June 2010 - 12:56 PM, said:

I do believe that with the VTR fan, you've seen improvement in your case. I believe the improvement is slow moving stop and go traffic, not stoplight to stoplight. As far as the VTR fan cooling better when stopped, I'm not buying it. There have been members who have made the switch and posted that while their stop and go traffic temps went down, their stop light temps increased.

We all agree, a pusher fan is only 80% efficient when compared to a puller fan. We also agree that the air in the tunnel is hotter than the air on the side of the bike, I measured a 67 degree difference earlier in this thread. Granted, once the fan starts the temp will come down, but it will never be as cold as the 'fresh' air on the side of the bike. When the bike is stopped, we can safely say the stock fan is the better choice.

We all agree that no fan helps above 30 mph(ish). We all agree that running a fan against the flow of air across a radiator is a bad thing.

I do see a big benefit to the VTR fan swap in the 10-30mph window. I believe, however, a large portion of the benefit is not so much that the VTR fan itself is aiding in cooling, but that you've removed the stock fan. Once the bike is in motion, the stock fan is fighting air flow caused by bike movement. Replacing the stock fan with the VTR fan just stops that fight.

The biggest reason for these bikes running hot, in most cases, is not the fan, but the A/F mixture. From the factory, they are so lean that they just make a ton of heat. Currently, I'm not running a fan control of any kind or a VTR fan, and my bike has no heat problems. Ever since I installed my PCV w/autotune, I've gotten rid of those lean spots and along with those went the high temps. I've found during the last couple rides, that I actually need to change my mapping a little because I'm having a problem with not enough heat. I couldn't get it over 172 on the freeway last Saturday.

All this fan talk is really just a band aid for a lean mixture (and too much/wrong antifreeze). If you really want to fix the problem, fix the mixture. Once you fix the mixture, you should be able to run which ever fan makes you feel better.

Well, I think your right about the lean points and what it takes to really fix the tune.
I've still got to install autotune on my bike.


Look forward to hearing the results.

:lurk:

I agree that fixing the lean running is a major part in keeping the motor cooler.
The motor in stock tune is particularly lean at low throttle/low RPMs such as encountered in slow moving traffic, where the overheating potential is greatest.
Another big source of heat is the catalytic converter.

A powercommander, good map and catless headers go a long way towards solving the problem.

O. T. slightly, I wonder also if fixing the lean running would help reduce valve seat recession resulting in less chance of valve clearances reducing? I guess only time will tell.

[image: View Post]JES_VFR, on 05 June 2010 - 04:08 PM, said:

I know that a pusher fan is less efficient than a tractor fan, unless is it's total surface is larger than the total surface of the radiator its has a complete shrouding duct.



Also, don't forget that this 80% figure quoted at this website is using their own fan spinning BACKWARDS to convert from a tractor to a pusher by reversing flow without changing the blade pitch.

Switching to the VTR fan changes the blade pitch to one that was designed to be a pusher.

Does the VTR suffer from a heat issue?

Perhaps there is something to the lean-running effecting the hot-running issue. But since I've personally had no more overheating issues with the fan swap I'm going to consider the problem fixed on my bike, and after a full season of it being fixed I'll just forget about the fan, the worry about overheating in traffic, and just get on with my life.

If people want to put in a bunch of cobbled-up switches and mess around trying to think FOR the cooling system rather than just fixing it once and for all and then being able to ignore it like any properly-designed vehicle where it just WORKS, then more power to them.

Me, I've found my solution. I thank you for showing it to me and convincing me to try it. It was one of the easiest mods I've ever done to the bike as well as one of the cheapest. So far it's just fixed the problem. I'm sick of fighting the nay-sayers who say it's not going to work.

It does.

[image: View Post]Serenity_VFR, on 08 June 2010 - 06:34 AM, said:

[image: View Post]JES_VFR, on 05 June 2010 - 04:08 PM, said:

I know that a pusher fan is less efficient than a tractor fan, unless is it's total surface is larger than the total surface of the radiator its has a complete shrouding duct.



Also, don't forget that this 80% figure quoted at this website is using their own fan spinning BACKWARDS to convert from a tractor to a pusher by reversing flow without changing the blade pitch.

Switching to the VTR fan changes the blade pitch to one that was designed to be a pusher.

Does the VTR suffer from a heat issue?

Perhaps there is something to the lean-running effecting the hot-running issue. But since I've personally had no more overheating issues with the fan swap I'm going to consider the problem fixed on my bike, and after a full season of it being fixed I'll just forget about the fan, the worry about overheating in traffic, and just get on with my life.

If people want to put in a bunch of cobbled-up switches and mess around trying to think FOR the cooling system rather than just fixing it once and for all and then being able to ignore it like any properly-designed vehicle where it just WORKS, then more power to them.

Me, I've found my solution. I thank you for showing it to me and convincing me to try it. It was one of the easiest mods I've ever done to the bike as well as one of the cheapest. So far it's just fixed the problem. I'm sick of fighting the nay-sayers who say it's not going to work.

It does.


That's incorrect, Perma-Cool has both push and pull fan designs, as do most manufactures.

The reason a puller is more efficient than a pusher is physics, not lack of ability to design a proper fan blade.

'Pullers' are always better at air (flow) management than a 'Pusher' would be. Creating a low pressure cell behind the fan will make any air out front want to rush into the radiator and fill in the low pressure area.
A 'pusher' creates a high pressure cell in front of the radiator and that high pressure will leak out everywhere it gets a chance to. Much of the air will leak out the sides and not go through the radiator. Pushing air tends to disburse it (everywhere). Pulling air tends to gather and focus the air flow. Proper ducting on a pushing fan will help force more of the 'disbursed' air through the radiator, as JES_VFR mentioned. The stock fan frame on the VFR doesn't have the ducting to improve the efficiency of a pusher fan. By installing a pusher fan on the VFR, you will decrease airflow through the radiator, at least while the bike is standing still.

The VTR fan works for you because your cooling problem is slow moving stop and go traffic, not long multiple stop lights. At low speed traffic, your improvement is as much to do with not having the stock fan working against airflow, as it is have the VTR fan working for you.

In the end, if it works for your situation, great, more power to you.

[image: View Post]coderighter, on 26 August 2009 - 08:00 PM, said:

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.


I was working on a high amp leaf switch setup that would break the fan circuit at a certain speed. The switch would be mounted in a small pod that would be attached onto that black plastic cover under the headlight. The trick is the paddle that is attached to the pod/mounting bracket. As the speed increases. the air push the switch into an open position, thereby cutting the power to the switch. Until the speed is reduced does the paddle return to a more vertical position, once again switching to a closed setting, allowing the fan to turn on. I am replacing a mill and should be able to make one soon.