5th Gen Gutless midrange -- Back to Stock Pipe?

I have a 2001 VFR800i. I've had the bike now for 18 months and I really like it as a general purpose machine. But I still don't understand why people say this bike has good torque. Under 8K it feels like I am riding a 400cc bike.

I have a Two-brothers carbon slip-on installed by previous owner. This sounds pretty good, but decent power really doesn't hit until the tach is pointing straight up (8000 rpm). On the highway if I need to pass, I'll drop to 5th or even 4th, then grab a fistfull of throttle... and I get a whole bunch of nothing. :huh: The exhaust note sound/tone gets deeper, but its as though the bike doesn't know how to accelerate. It just gets noisier as it slowly picks up speed (at about the rate of a family sedan)

My first-ever bike, an old-school XS-750 triple Yamaha, had much less peak horsepower, but would embarrass my VFR 800i in roll-on (below 7000 rpm) in any gear. That XS was old technology and had a smaller motor. Why is the VFR so gutless?

SO... How do I get more torque from 5K to 8K on the clock.

1. Should I source a stock pipe and dump the two brothers?

2. Do I need to fiddle with the air box?

3. Should I have the engine remapped?

Keep in mind I am more than happy with peak power starting at about 7500 RPM. The Motor is strong above 8K and very responsive to the thottle. Below 6K, however, it as if my right wrist simply makes the exhaust note drop an octave or two without doing much about changing speed.

Is there any simple tuning process to give the VFR800i some mid-range guts?

[image: View Post]Yo800, on 06 March 2011 - 03:15 PM, said:

I have a 2001 VFR800i. I've had the bike now for 18 months and I really like it as a general purpose machine. But I still don't understand why people say this bike has good torque. Under 8K it feels like I am riding a 400cc bike.

I have a Two-brothers carbon slip-on installed by previous owner. This sounds pretty good, but decent power really doesn't hit until the tach is pointing straight up (8000 rpm). On the highway if I need to pass, I'll drop to 5th or even 4th, then grab a fistfull of throttle... and I get a whole bunch of nothing. :huh: The exhaust note sound/tone gets deeper, but its as though the bike doesn't know how to accelerate. It just gets noisier as it slowly picks up speed (at about the rate of a family sedan)

My first-ever bike, an old-school XS-750 triple Yamaha, had much less peak horsepower, but would embarrass my VFR 800i in roll-on (below 7000 rpm) in any gear. That XS was old technology and had a smaller motor. Why is the VFR so gutless?

SO... How do I get more torque from 5K to 8K on the clock.

1. Should I source a stock pipe and dump the two brothers?

2. Do I need to fiddle with the air box?

3. Should I have the engine remapped?

Keep in mind I am more than happy with peak power starting at about 7500 RPM. The Motor is strong above 8K and very responsive to the thottle. Below 6K, however, it as if my right wrist simply makes the exhaust note drop an octave or two without doing much about changing speed.

Is there any simple tuning process to give the VFR800i some mid-range guts?


You may need a different bike. The motor here is an 800cc short-stroker that makes around 100 hp and 55 ft pds torque that can push a 550 pound bike to an hones 150+ mph. The relatively small motor makes its power based on piston speed, not displacement so the power is designed to come in at higher rpm. Those little 200cc pistons will never make much torque (yes, you can supercharge . . . .). There is no replacement for displacement. When people talk about this bike having decent torque, they're comparing it to peaky 600 race replicas, GSXR 750s, etc. It's great compared to those at the rpm range you describe.

The aftermarket can that's fitted to your bike allows even more peak power, but at the expense of lower end torque because of reduced exhaust back pressure, so that doesn't help. Return to the stock can would probably restore some midrange torque.

I like midrange torque, too (I have a ZRX that can rip my arms from their sockets - 79 ft pods at around 7K), but I like the VFR package better. What I did was use the stock can in combination with a PCIII and a custom dyno map that filled in a lot of missing midrange from the stock map. I'm very pleased. Probably $600, all in. Alternatively, you could fit a PCIII and map while leaving the aftermarket can in place and get an overall power increase everywhere, including the midrange. The stock VFR map and lack of backpressure are what's killing your midrange torque, but know that it will never be a torque monster.

[image: View Post]Misspent Youth, on 06 March 2011 - 03:46 PM, said:

I like midrange torque, too (I have a ZRX that can rip my arms from their sockets - 79 ft pods at around 7K), but I like the VFR package better. What I did was use the stock can in combination with a PCIII and a custom dyno map that filled in a lot of missing midrange from the stock map. I'm very pleased. Probably $600, all in. Alternatively, you could fit a PCIII and map while leaving the aftermarket can in place and get an overall power increase everywhere, including the midrange. The stock VFR map and lack of backpressure are what's killing your midrange torque, but know that it will never be a torque monster.
Who do you recommend for a map? I'm in Southern California. Can anyone recommend a speed shop that might re-map my 2001 VFR to run better with the Carbon pipe. It is quite a bit lighter than stock.


FYI, I did talk to a Honda team mechanic from the MotoGP team at Laguna Seca last summer. We chatted a bit. He personally owned a VFR and he said "stock pipe much better for street".

Some dumb questions - what gear are you in when you say it doesnt move?

Have you done a De- cat and added a BMC or K&N? PC3 mapping?

There is a well documented flat spot on the (00 - 01) 5th gen models, cured mostly with a remap power commander modual, or using the stock can. Even with the stock can there is a flat spot there due to the fueling issues with the first iteration of the vfrs open loop fuel injection. My 98 had the closed loop injection and no o2 sensors so it never went flat at that range, also it does not have a cat converter and a slightly larger header pipe. I noticed this when I was working on a friends yellow Y2k vfr and took it out for a ride, twisted the throttle at 5000 rpm to go up the hill and no response just like I had left it steady, then a little more and it took off. I think a used PC with a map built for the 2brothers pipe would cure that, find one on ebay or buy a pc3 usb - should cure that for around what it would cost to procure a stock pipe. All that being said its no big bore v twin its built to knock pistons 7-10k rpm for the twisties all day long, kick it down a gear for spirited passing shes got the HP if you rev it! She likes to be reved up.


2brothers map - there are several maps already availible for that slip on on power commanders site, and some here in the downloads section, the erion is almost identical.

[image: View Post]Yo800, on 06 March 2011 - 11:12 PM, said:

[image: View Post]Misspent Youth, on 06 March 2011 - 03:46 PM, said:

I like midrange torque, too (I have a ZRX that can rip my arms from their sockets - 79 ft pods at around 7K), but I like the VFR package better. What I did was use the stock can in combination with a PCIII and a custom dyno map that filled in a lot of missing midrange from the stock map. I'm very pleased. Probably $600, all in. Alternatively, you could fit a PCIII and map while leaving the aftermarket can in place and get an overall power increase everywhere, including the midrange. The stock VFR map and lack of backpressure are what's killing your midrange torque, but know that it will never be a torque monster.
Who do you recommend for a map? I'm in Southern California. Can anyone recommend a speed shop that might re-map my 2001 VFR to run better with the Carbon pipe. It is quite a bit lighter than stock.


FYI, I did talk to a Honda team mechanic from the MotoGP team at Laguna Seca last summer. We chatted a bit. He personally owned a VFR and he said "stock pipe much better for street".



Mike Velasco, former tuner for Fred Merkel and others, did mine. He's at the Brothers in Bremerton, WA. http://www.brothersp....asp?pg=service

Did a good job, but probably any decent PCIII shop can do as well. They use a formula and the computer does a lot of it.

[image: View Post]HispanicSlammer, on 06 March 2011 - 11:52 PM, said:

There is a well documented flat spot on the (00 - 01) 5th gen models

Didnt know that - good info....

Drop a tooth on the countershaft sprocket?

Thanks for the help guys. I don't want to change the sprockets as I don't really want to spin more revs all the time.

The disappointing roll-on is in 6th, 5th, and to lesser extent 4th on freeway. Bike doesn't feel strong unless I go all the way down to third and really spin it up. I'm not expecting literbike performance, but when I grab full throttle in 5th, nothing much happens.

I'll look at the mapping options in the download section. FYI, the previous owner did an airbox mod and removed the Calif. 02 sensor. Could that be part of the issue. The bike does feel very strong and fast from 7500 rpm and up. At 8K she starts to sing. But I don't like to have to drop THREE gears to pass trucks. I didn't even have to do that on an XV550 I had years ago.

Which map should I look for?

Start with the basics... Make sure your air filter is clean, if it is a K&N or BMC filter it may be contributing to your midrange fueling being too lean with the slip-on.
Another thing that made a noticable improvement on my 5th gen was adding a half a can of seafoam to a fresh batch or regular gas since high octane causes
an even leaner condition due to its burn rate (other people on this site could explain it better). and also not required on the 5th gen as per Honda.
If an aftermarket air filter and slip-on are installed the pc3 usb or dobeck tfi module would help a lot and in some cases better milage was reported
due to having less throttle position to do the same amount of work... and imho if you have the desnorkel mod that too may change low rpm performance
(some feel no change at all) but its hard to get accurate dyno reports because dyno cooling fans cant produce the same amount of frontal air pressure
a bike has at speed. And since the airbox and its snorkel are designed to take advantage of that high pressure area and most of us lack a wind tunnel dyno
it might contribute to your problem as well. A crappy old set of spark plugs can also take a little midrange away. And as I said this is only my opinion.
My point is see what you have filter wise and if any mods were done by you or previous owner and pour seafoam in and run it right up to redline
getting on the freeway and vary your throttle position in all gears so the seafoam has the best chance at cleaning the injectors making sure they
deliver the amount of fuel the clean nozzles are supposed too. making them richer in the process, if its not enough follow the advise of others and try a fuel management
system. Sounds like you have the 02 bypass modules. check their values to make sure they are in range because if they arent it, it could tell the ecm its rich and shorten
Injector open time by several milliseconds and creating a lean condition and do it without triggering the MIL or FI light if you prefer.
As far as my bike goes.... Rev it to 5k, crank it wide open and by 5500 its lofting the wheel in first gear, no pc3, with a stock paper air filter, o2 sensors and snorkel in place
with a Dual tip Blue Flame slip on with lower spud out.
Good luck!! let us know what actually works for you. The more info you have... The more informed we will all be....

[image: View Post]Yo800, on 06 March 2011 - 03:15 PM, said:

SO... How do I get more torque from 5K to 8K on the clock.

1. Should I source a stock pipe and dump the two brothers?

2. Do I need to fiddle with the air box?

3. Should I have the engine remapped?


1) No, keep the pipe. Any aftermarket pipe will give you more power across the entire powerband; once the gases have joined in the collector, you want to get them out as quickly and efficiently as possible. Do not confuse backpressure with exhaust gas velocity -- backpressure = loss of energy, and the stock pipe will just add power robbing backpressure. When I added the Staintune on my bike back in the day, power did not drop at any point in the powerband.

2) You can try if you want, but the gains are very minimal. Remove the snorkel if you want a deeper intake roar, but altering the actual airbox itself too far from stock can be very detrimental to performance.

3) Yes. A good map will smooth out power delivery and allow you to richen up the lean spots in the powerband, which in turn frees up some ponies and makes the bike feel more responsive and powerful.



If you want more bottom end grunt, and you still have the stock gearing, swap the sprockets to a -1/+2 setup. -- it will really wake the bike up. There is only so much 781cc can do for a 500+lb bike, so unless you want to add forced induction or nitrous, you'll never get the feeling of big-bike torque. Your old 750 had different cams, gearing, and a much lower rpm limit, so comparing 5000rpm on both bikes is not apples to apples. The VFR likes to rev out to 12k, so use gearing to make better use of the power available.

[image: View Post]Yo800, on 07 March 2011 - 02:18 AM, said:

Thanks for the help guys. I don't want to change the sprockets as I don't really want to spin more revs all the time.

The disappointing roll-on is in 6th, 5th, and to lesser extent 4th on freeway. Bike doesn't feel strong unless I go all the way down to third and really spin it up. I'm not expecting literbike performance, but when I grab full throttle in 5th, nothing much happens.



Well - there you have it. At the lower revs under 5500, its unrealistic to expect torqky roll on ability like a liter bike in 5th and 6th gear. Its not a twin or a big bore. Maybe conbined with the '00-'01 5th flat spot going on, you have the wrong bike for what you want. VFRs like the right gear for the right situation. (I usually do a kick down to 4th on a freeway pass) -- Mbe go for the flat spot fix or bum a ride on a '98 or '99 and see if there's a difference for you

+ 1 to toro's comments

[image: View Post]mello dude, on 07 March 2011 - 05:11 PM, said:

[image: View Post]Yo800, on 07 March 2011 - 02:18 AM, said:

Thanks for the help guys. I don't want to change the sprockets as I don't really want to spin more revs all the time.

The disappointing roll-on is in 6th, 5th, and to lesser extent 4th on freeway. Bike doesn't feel strong unless I go all the way down to third and really spin it up. I'm not expecting literbike performance, but when I grab full throttle in 5th, nothing much happens.



Well - there you have it. At the lower revs under 5500, its unrealistic to expect torqky roll on ability like a liter bike in 5th and 6th gear. Its not a twin or a big bore. Maybe conbined with the '00-'01 5th flat spot going on, you have the wrong bike for what you want. VFRs like the right gear for the right situation. (I usually do a kick down to 4th on a freeway pass) -- Mbe go for the flat spot fix or bum a ride on a '98 or '99 and see if there's a difference for you

+ 1 to toro's comments





Before I purchased this 2001, I did test a '99 VFR 800, stock everything, no mods. It actually did feel much snappier from 4500-6500 rpm, but it's hard to conclude much from a 5 min 'round the block ride.


I will check air filter, plugs, some of the other little things mentioned above. I do get pretty good mileage on long trips (42-43), but that's driving very conservatively.

Actually sounds to me like there's been a problem with this bike from your purchase! :blink:

Really, maybe a bad injector or plug or something as no VFR runs as poorly as you described! Even poorly mapped or no map for mods pulls well from way lower than your having issues with IMO.

Once you fingue out what the real problem is, then toss on a 16t front sprocket and you'll be even happier! :beer:

BR

Before you change anything, put the damn thing on the dyno with a lambda probe up its ass and see how she's really running! Then you'll know if there is actually a problem, or if its just the nature of the beast.

[image: View Post]Yo800, on 07 March 2011 - 06:01 PM, said:

Before I purchased this 2001, I did test a '99 VFR 800, stock everything, no mods. It actually did feel much snappier from 4500-6500 rpm, but it's hard to conclude much from a 5 min 'round the block ride.

I will check air filter, plugs, some of the other little things mentioned above. I do get pretty good mileage on long trips (42-43), but that's driving very conservatively.


My stock '98 came with a free-flowing slip-on and felt weak on the roll-on (this is pre-PCIII). I definitely restored midrange snap when I installed a stock can. I liked the stealth approach and so left the stocker in place when I dialed in the PCIII.

[image: View Post]kostritzer, on 07 March 2011 - 06:30 PM, said:

Before you change anything, put the damn thing on the dyno with a lambda probe up its ass and see how she's really running! Then you'll know if there is actually a problem, or if its just the nature of the beast.




That makes sense. And I may try to "borrow" a stock pipe and do an immediate comparison. What suprised me is that, in researching the maps available online, it appears most of the mapping jobs added only 1.5-2lbs of torque from 4500-6500 rpm. I'm not sure that's worth the investment. But as Kostritzer notes, first thing is to get it on a dyno.


I live in Ventura county, CA -- anybody have suggestions for a good dyno shop within an hour's ride?