V-Tec Advantage - Or Not

Can anyone point me to a comparison of V-Tec and pre V-Tec power/torque curves? To be a worthwhile comparison they would have to be from the same dyno on the same day with both bikes. I'm interested in quantifying the exact advantage V-tec provides.

Hey Ken,

All the vtec did was add a glitch in the smoothness of the normally seamless power of a 5th gen, still a blast to ride though.

If you are refering to the 8th gen 800, I here there are much smoother then the 6th gen version.

You are correct Bailey....from my test ride of the new 800 when it first came out, the engine felt as close to a 5th Gen as I think it could ever get. 5th Gen is still the best engine of the 2 from a riding perspective imo. But I've never seen want the OP wants.

Et voila!

[image: IM000015.jpg]

If I'm reading the chart correctly (please correct me if I'm wrong), the VTEC motor produces less, (or at best matches) the HP and torque of the 5th gen motor all the way to about 9,000 rpm. I spend the vast majority of my riding below that. IMO disappointing given the extra complexity and cost of incorporating the technology.

Dutchy

Et voila!

Nice pull, Dutchy! I am sure this has been hammered to death in older threads, but I always assumed the VTEC was a regulatory gambit -- a way for Honda to meet emissions requirements at the certification engine speed (3K-5K?), and yet still hit their desired peak HP goals. If that's the case, then we're never going to see the rationale for VTEC in an HP/torque chart because one of the chief parameters against which Honda optimized (emissions) isn't on that chart. As riders, we attempt to fix the issue with Power Commanders and wonder why Honda can't figure this out. As a practical matter, a Power Commander functions as an end-run around emissions regulations that Honda simply can't duck as a large manufacturer (cf the massive VW brouhaha last year), but that we (and Dynojet) can as a smallish number of enthusiasts that legislators and regulators choose (for the time being) to ignore.

that's what it looks like to me, simple solution though, shift down twist wrist. problem solved.

I agree though you would think that since 86 they could have got this to put out a little more power. in 20+ years they could not up the horse power by more than 7

The chart is from the respected german mag Das Motorrad.

The explanation is the more relaxed legislation on noise and polution in the olden days....

When I eventually returned to the Netherlands after 7 years abroad and went to get my LeMans a set of Dutch plates, it failed the regulations. If not for the tester being a mc nut himself, I would have been forced to fit more restrictive mufflers.....

RobF

Dutchy

Et voila!

Nice pull, Dutchy! I am sure this has been hammered to death in older threads, but I always assumed the VTEC was a regulatory gambit -- a way for Honda to meet emissions requirements at the certification engine speed (3K-5K?), and yet still hit their desired peak HP goals. If that's the case, then we're never going to see the rationale for VTEC in an HP/torque chart because one of the chief parameters against which Honda optimized (emissions) isn't on that chart. As riders, we attempt to fix the issue with Power Commanders and wonder why Honda can't figure this out. As a practical matter, a Power Commander functions as an end-run around emissions regulations that Honda simply can't duck as a large manufacturer (cf the massive VW brouhaha last year), but that we (and Dynojet) can as a smallish number of enthusiasts that legislators and regulators choose (for the time being) to ignore.

Nail/head! :beer:

Nice find Dutchy.

I scanned that yeeaaaaaaars ago from the actual mag :-)

Those of you who are ducking under the radar with PC's and the like on street bikes might want to get caught up with recent developments. EPA is about to double down on this.

Not surprising I suppose. All they have to do is read bike forums to know that it's quite common for owners to disable, remove or alter emissions related components. Where I live, bikes are not inspected nor emissions tested, so just about anything goes. That will probably catch up with us some day.

"The purpose of the VTEC system on the Interceptor, of course, is a broadening of the power curve. Operation on two valves per cylinder at lower rpm levels increases power and torque, while operation on four valves per cylinder at higher rpm levels increases horsepower and torque. Most engines must be tuned to compromise power at one (or both) extremes of the rpm range. With VTEC, the Interceptor does not have to accept this compromise. "

[image: 01-02vfrdyno.jpg]

Thanks for the chart Dutchy, just what I wanted.

My reason for asking is because I have always believed that the V-Tec addition was a complete waste of time and although that chart confirms this to me, it's not a total slam dunk. The V-Tec engine certainly lags behind in the mid range torque, but that catches up and carries on making more power at the top end of the rev range, that area we never normally make use of.

So one could say then the V-Tec system does marginally broaden the spread of power, although with that mid range loss I'd say it is of very questionable merit, especially as I have no doubt, they could have achieved that higher top end without resorting to the unnecessary complexity of V-Tec.

So why do they do it? Because they can. Historically, V-tec was developed for cars and used oil pressure to push a pin into a rocker arm that then provided higher lift. A simplistic form of variable valve timing and it worked quite well on the larger engines of cars, although there are now far, far better systems in use that can provide finer control over the timing. Even on bikes this has been achieved to great effect with Ducati's new DVT system. But that has a slightly different purpose. Rather than needing to make more power and/or torque, they need to calm down the valve overlap at low speed or a big high power twin shakes itself to pieces at low revs. By softening the valve timing, the engine runs MUCH better at low rpm. Try a Multistrada with and without DVT if you want to feel the effect yourself.

But Honda developed V-Tec many years ago and to be honest they've fallen into a rut with it and don't want to give it up. Even worse, the translation to smaller bike engines was never very successful, as evidenced by the chart Dutchy kindly provided. There's a lot of additional mechanical complexity which adds the potential for failures and significantly increases servicing costs. And all for what? Well, not a lot really and nothing that couldn't be obtained by other simpler and cheaper means. Let's face it, if it really was any good, they would use it on other machines.

It's hard to escape the fact that V-Tec on the VFR is a albatross that should be eliminated from the engine. In truth there was nothing wrong with the Gen 5 engine. It can make all the power they would want it to, around about 100hp is the design goal. Could that be increased, sure, but it's not really needed. Having said that, why not make it full RC45 spec as that pulls like a train AND has a better top end. No doubt they'd need a cat now, but I don't believe there's anything fundamentally wrong with that engine that some updated electronics wouldn't sort (for emissions etc, not adding stupid and unnecessary power modes).

The trouble is, motorcycle manufacturers have fallen into the same trap as so many manufacturers of other types of product. They have to keep updating and changing and fail to see that in so many cases they're making it worse. But it's the general buying public who force them into this position by continually demanding change, even when something is basically already perfect at what it does. I have even read on this forum critical comments about the 8th gen, saying it's a rehashed old engine and frame design. Well both may have been designed some years ago, but what precisely would a more 'modern' version do? The engine does everything that is required of it. It is a paragon of smooth usable power (ignoring V-tec), better than many other more modern designs with a similar aim. Handling? What more do you want, let alone need. The very first VFR750 was able to achieve a third place in an international race, ridden by Ron Haslam at Donnington against the very best riders in the world on their world championship machines - I watched him do it. And the handling has certainly not got worse over the years. Change just for the sake of change is not to be desired. As the old saying goes, if it ain't broke, don't try and fix it. As far as I'm concerned, Honda tried to fix the unbroken VFR800, and broke it.

I don't mean to annoy those of you with a V-tec, but you have to ask yourselves the question, wouldn't it actually be a better bike without V-Tec. You know it would. Sadly, if you want a new bike, Honda have given you no other option.

It's like my wife is fat and she never stops Bitching ! Why don't I leave her ? Because I Love her and I'm so stupid I don't know anything else ?

PairOfAces

It's like my wife is fat and she never stops Bitching ! Why don't I leave her ? Because I Love her and I'm so stupid I don't know anything else ?

+1 This topic has been covered a dozen times and the out come is always the same, if do not like the concept of VTEC don't buy it .

Fwiw, I love mine. :-) Vtec that is. For such a maligned model of VFR they seem to be extremely reliable. Mine is great, and this is from a prior 5th gen owner. :-)

Vtec is annoying, but nowhere bad enough for me to choose another bike. I love the VFR.

I couldn't decide if I liked it or not so I bought one of each! :goofy:

For me maybe its miles on the engine or familiarity with the bike but the vtec transition is not a problem for me. The low end snatchiness is problematic but not enough for me to make any changes in nearly 7 years ownership. Instead I enjoy the overall competence of the machine. I did try a vtec with a PC installed but really didn't feel a huge improvement. Made me realize riding the thing is more fun than picking nits and piling on with the negative non vtec owners. Way too many bikes on the market to fixate on the perceived shortcomings of one model.

BiKenG

Thanks for the chart Dutchy, just what I wanted.

My reason for asking is because I have always believed that the V-Tec addition was a complete waste of time and although that chart confirms this to me, it's not a total slam dunk. The V-Tec engine certainly lags behind in the mid range torque, but that catches up and carries on making more power at the top end of the rev range, that area we never normally make use of.

So one could say then the V-Tec system does marginally broaden the spread of power, although with that mid range loss I'd say it is of very questionable merit, especially as I have no doubt, they could have achieved that higher top end without resorting to the unnecessary complexity of V-Tec.

So why do they do it? Because they can. Historically, V-tec was developed for cars and used oil pressure to push a pin into a rocker arm that then provided higher lift. A simplistic form of variable valve timing and it worked quite well on the larger engines of cars, although there are now far, far better systems in use that can provide finer control over the timing. Even on bikes this has been achieved to great effect with Ducati's new DVT system. But that has a slightly different purpose. Rather than needing to make more power and/or torque, they need to calm down the valve overlap at low speed or a big high power twin shakes itself to pieces at low revs. By softening the valve timing, the engine runs MUCH better at low rpm. Try a Multistrada with and without DVT if you want to feel the effect yourself.

But Honda developed V-Tec many years ago and to be honest they've fallen into a rut with it and don't want to give it up. Even worse, the translation to smaller bike engines was never very successful, as evidenced by the chart Dutchy kindly provided. There's a lot of additional mechanical complexity which adds the potential for failures and significantly increases servicing costs. And all for what? Well, not a lot really and nothing that couldn't be obtained by other simpler and cheaper means. Let's face it, if it really was any good, they would use it on other machines.

It's hard to escape the fact that V-Tec on the VFR is a albatross that should be eliminated from the engine. In truth there was nothing wrong with the Gen 5 engine. It can make all the power they would want it to, around about 100hp is the design goal. Could that be increased, sure, but it's not really needed. Having said that, why not make it full RC45 spec as that pulls like a train AND has a better top end. No doubt they'd need a cat now, but I don't believe there's anything fundamentally wrong with that engine that some updated electronics wouldn't sort (for emissions etc, not adding stupid and unnecessary power modes).

The trouble is, motorcycle manufacturers have fallen into the same trap as so many manufacturers of other types of product. They have to keep updating and changing and fail to see that in so many cases they're making it worse. But it's the general buying public who force them into this position by continually demanding change, even when something is basically already perfect at what it does. I have even read on this forum critical comments about the 8th gen, saying it's a rehashed old engine and frame design. Well both may have been designed some years ago, but what precisely would a more 'modern' version do? The engine does everything that is required of it. It is a paragon of smooth usable power (ignoring V-tec), better than many other more modern designs with a similar aim. Handling? What more do you want, let alone need. The very first VFR750 was able to achieve a third place in an international race, ridden by Ron Haslam at Donnington against the very best riders in the world on their world championship machines - I watched him do it. And the handling has certainly not got worse over the years. Change just for the sake of change is not to be desired. As the old saying goes, if it ain't broke, don't try and fix it. As far as I'm concerned, Honda tried to fix the unbroken VFR800, and broke it.

I don't mean to annoy those of you with a V-tec, but you have to ask yourselves the question, wouldn't it actually be a better bike without V-Tec. You know it would. Sadly, if you want a new bike, Honda have given you no other option.

Ken yr wrong. Rob got it right in post #6. Honda introduced the VTEC to enable the VFR to pass international emissions legislation. Simple as that. The Gen 5 would have failed and the costs to get it through would have been astronomical when they had VTEC sat on the shelf as a technology waiting to go.

I do agree though that there should be other ways around it by now; it adds weight & complication which is not needed nor does it do much if anything for the rider.

Not to mention the pain in the ass job of checking the vtec clearances.

Skids

Ken yr wrong. Rob got it right in post #6. Honda introduced the VTEC to enable the VFR to pass international emissions legislation. Simple as that. The Gen 5 would have failed and the costs to get it through would have been astronomical when they had VTEC sat on the shelf as a technology waiting to go.

Nope. I am 99% sure that is not correct. I may not actually have any inside information on this, but having worked for Honda I have a pretty good idea how they think and they do love to hang on to any special technology they have developed. As for needing it to pass emissions. Nah, I don't believe that. There's nothing wrong with the pre V-tec engine that requires this additional technology to comply and that couldn't be done with electronics. It is a very well designed engine after all. When introduced on the VFR, all the hype was about spread of power, no mention of emissions which I believe have nothing to do with it.

V-tec is a worthless technology. As I said, if it's so good, they'd use it on other bikes. They don't because it provides nothing that cannot be obtained by other better means. But Honda see it as their unique technology and don't want to be seen to give up on it.

As for the 6th Gen VFR, I am not knocking the bike, nor those that choose to buy and ride one. I'm not saying it's a bad choice. My complaint is levelled solely at Honda for forcing customers down this route, unnecessarily and just for their own reasons that have nothing to do with good bike design. This is not a rant, just an interesting technical discussion. I don't care whether Honda continue with V-Tec or not, even if I disagree with their choice. I'm not interested in any VFR as standard. I like my 1200 eVo4 conversion and my 800 will similarly fit my requirements. I don't need Honda to produce any new V4 just to suit me, that's not what I'm saying. In fact, I didn't even start this topic to argue against V-tec. All I actually wanted was some power comparison data for my own interest and I had no intention to ruffle anyone's feathers. My apologies if I have.

I can't remember the source, but I was under the impression that the main reason was noise levels, not emissions; that the whine from the gear drive would fail pending changes in EPA noise standards.

Again. no inside knowledge here, but I doubt that's the case. The noise isn't that pronounced and in any case, changing to chain doesn't mean they had to include V-tec.

Optimizing engine breathing: how VTEC works

[image: 3_a1.gif]

An elegant, simple mechanism

Switching between high and low valve lift using two cam profiles and two rocker arms per cylinder.

[image: 3_a2.jpg]

The switch is made using hydraulic pressure to push/release the sliding pin, locking/unlocking the middle rocker arm and the other rocker arm.

At low engine speeds, the pin is retracted, disengaging the middle rocker arm. The valves are operated by the two outside, low-profile cams for a low valve lift.

At higher engine speeds, increased hydraulic pressure pushes the pin, engaging the middle rocker arm. The valves are operated by the middle, high profile cam for high valve lift.

VTEC: a deceptively simple mechanism that uses hydraulic pressure to switch

VTEC was around BEFORE increased emissions restriction .

Well I guess that depends on your understanding of the concept "deceptively simple". I never liked the way the hydraulic pressure just smashes the locking pin against the rocker and hopes to locate into the hole as it moves past. A horrible idea that makes me think of terribly mashed up pins ends and rocker holes. But it doesn't appear to actually happen and it's all as reliable as anything Honda. Doesn't mean I have to like it though.

I wouldn't object to such complexity if there was any actual value to it, but that's my point really, there is no value. They just use it because they can and they thought it up a long time ago when it had more relevance, which it doesn't any more in today's age of electronic control. I don't lie awake at night worrying about it, but I do believe the VFR800 would be a better bike if they dropped V-tec.

If you want simple variable valve control, look at Suzuki's new GSXR1000 due for release soon. Instead of Ducati's hydraulic control, on the Suzuki the cam wheel uses a simple ball and ramp mechanism to move the relative position of the cam as the speed increases, which is essentially all you need. Soft timing at low rpm and moving SMOOTHLY to greater overlap with increasing engine speed. Doesn't even need any fancy electronic control as far as I can tell.

Now that's what I call "deceptively simple" :biggrin:

BiKenG

Skids

Ken yr wrong. Rob got it right in post #6. Honda introduced the VTEC to enable the VFR to pass international emissions legislation. Simple as that. The Gen 5 would have failed and the costs to get it through would have been astronomical when they had VTEC sat on the shelf as a technology waiting to go.

Nope. I am 99% sure that is not correct. I may not actually have any inside information on this, but having worked for Honda I have a pretty good idea how they think and they do love to hang on to any special technology they have developed. As for needing it to pass emissions. Nah, I don't believe that. There's nothing wrong with the pre V-tec engine that requires this additional technology to comply and that couldn't be done with electronics. It is a very well designed engine after all. When introduced on the VFR, all the hype was about spread of power, no mention of emissions which I believe have nothing to do with it.

V-tec is a worthless technology. As I said, if it's so good, they'd use it on other bikes. They don't because it provides nothing that cannot be obtained by other better means. But Honda see it as their unique technology and don't want to be seen to give up on it.

As for the 6th Gen VFR, I am not knocking the bike, nor those that choose to buy and ride one. I'm not saying it's a bad choice. My complaint is levelled solely at Honda for forcing customers down this route, unnecessarily and just for their own reasons that have nothing to do with good bike design. This is not a rant, just an interesting technical discussion. I don't care whether Honda continue with V-Tec or not, even if I disagree with their choice. I'm not interested in any VFR as standard. I like my 1200 eVo4 conversion and my 800 will similarly fit my requirements. I don't need Honda to produce any new V4 just to suit me, that's not what I'm saying. In fact, I didn't even start this topic to argue against V-tec. All I actually wanted was some power comparison data for my own interest and I had no intention to ruffle anyone's feathers. My apologies if I have.

Let's agree to disagree then. :beer:

If Ken will forgive a bit more friendly argument about the rationale for VTEC...

We have two alternative theories in play here:

#1) VTEC was introduced as a performance enhancement

#2) VTEC was introduced as a flawed(?) response to stricter regulation

Now I don't have any real evidence and I've read hardly any industry press over the past twenty years, so I am a poor historian. Still, I can't quite bite on theory #1. To my mind, the decisive evidence against theory #1 is the almost total lack of actual performance improvement. Other than some small gains at the very top of the HP curve, the VTEC mill fails to improve upon the 5th Gen and, worse, it pays for this lack of improvement with an unsettling notch in the middle of the power curve and troublesome valve maintenance.

I'm prepared to lay any of the usual corporate sins at Honda's feet: misreading the market, being short-sighted, etc. But I can't bring myself to believe they don't understand motorcycles or aren't competent engineers. They saw then the same power curve comparisons we see now.

I have seen the marketing blurbs Switchblade posted. I see the way that bolsters theory #1. In my mind, I file that under "the marketing department being the marketing department". They will always put the best possible spin on a development regardless of whether or not that spin reflects the actual history of that development.

I guess if I really wanted to move this beyond coffee house speculation, I would have to research whether or not any significant new regulations were actually introduced around 2002. It could have been later than that, as Honda would need to anticipate the full life of the 6h Gen.

RobF

If Ken will forgive a bit more friendly argument about the rationale for VTEC...

We have two alternative theories in play here:

#1) VTEC was introduced as a performance enhancement

#2) VTEC was introduced as a flawed(?) response to stricter regulation

Now I don't have any real evidence and I've read hardly any industry press over the past twenty years, so I am a poor historian. Still, I can't quite bite on theory #1. To my mind, the decisive evidence against theory #1 is the almost total lack of actual performance improvement. Other than some small gains at the very top of the HP curve, the VTEC mill fails to improve upon the 5th Gen and, worse, it pays for this lack of improvement with an unsettling notch in the middle of the power curve and troublesome valve maintenance.

I'm prepared to lay any of the usual corporate sins at Honda's feet: misreading the market, being short-sighted, etc. But I can't bring myself to believe they don't understand motorcycles or aren't competent engineers. They saw then the same power curve comparisons we see now.

I have seen the marketing blurbs Switchblade posted. I see the way that bolsters theory #1. In my mind, I file that under "the marketing department being the marketing department". They will always put the best possible spin on a development regardless of whether or not that spin reflects the actual history of that development.

I guess if I really wanted to move this beyond coffee house speculation, I would have to research whether or not any significant new regulations were actually introduced around 2002. It could have been later than that, as Honda would need to anticipate the full life of the 6h Gen.

I never quote anything from "Honda" .

Just to be clear .

V-tec is bolox, end off. :goofy:

And VTEC was introduce in 1989 for Honda on the 1989 Integra for driveability it not mistaken

Switchblade

I never quote anything from "Honda" .

Just to be clear .

Switchblade

"The purpose of the VTEC system on the Interceptor, of course, is a broadening of the power curve. Operation on two valves per cylinder at lower rpm levels increases power and torque, while operation on four valves per cylinder at higher rpm levels increases horsepower and torque. Most engines must be tuned to compromise power at one (or both) extremes of the rpm range. With VTEC, the Interceptor does not have to accept this compromise. "

...in quotation marks earlier in the thread and assumed it was some bit of marketing-ese from Honda (maybe a second-hand quotation passed along via industry journalists) back when the VTEC VFR was being rolled out.

RobF

Switchblade

I never quote anything from "Honda" .

Just to be clear .

Fair enough. I saw this:

Switchblade

"The purpose of the VTEC system on the Interceptor, of course, is a broadening of the power curve. Operation on two valves per cylinder at lower rpm levels increases power and torque, while operation on four valves per cylinder at higher rpm levels increases horsepower and torque. Most engines must be tuned to compromise power at one (or both) extremes of the rpm range. With VTEC, the Interceptor does not have to accept this compromise. "

...in quotation marks earlier in the thread and assumed it was some bit of marketing-ese from Honda (maybe a second-hand quotation passed along via industry journalists) back when the VTEC VFR was being rolled out.

No it was in a magazine.

My friend Makota San was a previous Chief Engineer Honda R&D who
invented Honda's VTEC... he calls VTEC "his baby" and recalls his boss
being super skeptical of the idea working at all...

I kid that VTEC means... Vacillating Torque Engine Compartment... seriously it worked on heavy cars
but it's proved to be too radical on a lighter bike... radical for Honda is that 50% love it but 50% hate it...




[image: 2013MakotoSanMrRC45_zps119ae64b.jpg]

Makota San also worked on the NR500 oval piston racer and he plans to
visit the Busy Little Shop some day because I have 2 cylinder blocks
off the NR500 that I packed out of Japan in 1981...
[image: gallery_3131_5511_17541.jpg]

Makota San down on cannery row...
[image: gallery_3131_5511_48694.jpg]

Often is the case that design engineers get a bee in their bonnet about some engineering concept that they see as "their baby" whether it is a good idea or not.

Having owned 4th gen 5th gen, 2x 6th gens, and now an 8th gen, in my opinion both the 6th and 8th gen bikes would be better bikes and more popular without the unnecessary complication of vtec

Honda tried to spin it otherwise, but by introducing the Vtec on the 6th gen VFR, the 2002 VFR already meet the tighter emission standards coming in 2006.

To the OP I don't see the point of this conversation unless your just asking about the 8th gen VFR. The Pro/Con of Vtec has been beaten to death here for the last 14 years so unless your just Trolling I don't see the point??? :unsure:

Spend a few weeks reading the dozens of threads on the subject from 2002 on and come back when your done. :491:

BR

It's the downward spike at 6500 that ruined the VFR. Honda.....end the V-Tec. It may work in Civics but it singlehandedly killed the legendary VFR. That's why I ride an RC36.

If it were in fact for emissions, wouldn't more bikes have/need it? The Civic and Integra fans went crazy for the V-tec...........It seems like Honda wanted another feather in their cap........

Baileyrock

Spend a few weeks reading the dozens of threads on the subject from 2002 on and come back when your done. :491:

BR

If I read this post correctly, content in generations was just purged to no more than 600 days.

http://www.vfrdiscussion.com/forum/index.php/topic/82906-i-did-a-bunch-of-server-maintenance-this-morning/

If the 6th gen bike was built with all the same modifications ( styling, suspension, exhaust, engine upgrades, ect.) but instead of VTEC still had the gear driven cams would it be a better bike? In my book, yes. No 6000 rpm dip, a flatter curve and easier to service and more reliable valve train I believe would have made the 6th gen a true upgrade from the 5th. The gear driven cams were Honda's response to major cam wear issues. They sought to restore public confidence with a high end solution that made their V4 rise to the echelons of motorbike engineering. I have a 6th gen and am fine with it's performance but for me keeping the gear driven cams would have been a win win.

Baileyrock

To the OP I don't see the point of this conversation unless your just asking about the 8th gen VFR. The Pro/Con of Vtec has been beaten to death here for the last 14 years so unless your just Trolling I don't see the point??? :unsure:

Spend a few weeks reading the dozens of threads on the subject from 2002 on and come back when your done. :491:

There's always one isn't there. Sigh. Why do you feel the need to be so disrespectful of others.

I've already been quite clear about the reasons behind my original request for data (to which Dutchy kindly responded with the information I sought). I see no reason to have to repeat them for your benefit.

Scan from the same mag

"The boys are back in town"

[image: IM000018.jpg]

That's a good shot. Shame it's missing some members.

Wow for a bike that's been around for 14 years it is amazing the chatter that is still generated about the v-tec.

Dutchy

Scan from the same mag

"The boys are back in town"

[image: IM000018.jpg]

Clearly the VTEC is in front !!!

Thanks Dutchy ....

Baileyrock

Honda tried to spin it otherwise, but by introducing the Vtec on the 6th gen VFR, the 2002 VFR already meet the tighter emission standards coming in 2006.

To the OP I don't see the point of this conversation unless your just asking about the 8th gen VFR. The Pro/Con of Vtec has been beaten to death here for the last 14 years so unless your just Trolling I don't see the point??? :unsure:

Spend a few weeks reading the dozens of threads on the subject from 2002 on and come back when your done. :491:

BR

I agree and why post a topic like this, for what purpose Ken? Are you trying to persuade yourself into purchasing a 6th. I don't get it.

It's like the big let down when the 7th gen was released. You know I don't like the bike BUT I respect the members that purchased the 7th gen.

I already explained why I asked the question and already thanked Dutchy for his information which is all I wanted. Try reading instead of trying to start an argument.

BiKenG

I already explained why I asked the question and already thanked Dutchy for his information which is all I wanted. Try reading instead of trying to start an argument.

Take your own advise !

If you just want Dutchy advise just email him and spare us the rest of the BS.

Switchblade

PairOfAces

It's like my wife is fat and she never stops Bitching ! Why don't I leave her ? Because I Love her and I'm so stupid I don't know anything else ?

+1 This topic has been covered a dozen times and the out come is always the same, if do not like the concept of VTEC don't buy it .

Or if you don't like the huge torque hole from 5-9k RPM that is seen in the chart Dutchy posted then do what we did buy a better looking (arguably) 6G with better suspension (no doubt) and better LBS (again, doubtless) and put in a 5G engine.

Switchblade

Optimizing engine breathing: how VTEC works

[image: 3_a1.gif]

An elegant, simple mechanism

Switching between high and low valve lift using two cam profiles and two rocker arms per cylinder.

[image: 3_a2.jpg]

The switch is made using hydraulic pressure to push/release the sliding pin, locking/unlocking the middle rocker arm and the other rocker arm.

At low engine speeds, the pin is retracted, disengaging the middle rocker arm. The valves are operated by the two outside, low-profile cams for a low valve lift.

At higher engine speeds, increased hydraulic pressure pushes the pin, engaging the middle rocker arm. The valves are operated by the middle, high profile cam for high valve lift.

VTEC: a deceptively simple mechanism that uses hydraulic pressure to switch

VTEC was around BEFORE increased emissions restriction .

Dave I don't think that is the bike version as they do not have variable valve lift as the Honda (and other) car engines. They simply use the hydraulics to shut off one exhaust and one intake valve at lower rpms.

Think of more like a fat man trying to breath through a straw. The smaller the straw the faster the air has to move to get enough to fill the lungs (cylinders). A larger diameter straw (opening the other two valves per cylinder) allows the guy to pull a breathe at higher RPM if you will.

BiKenG asked for numbers between two bikes which is a perfectly valid and objective question. The bikes are both VFRs so one would think the question is acceptable for a...........VFR FORUM! By the way, I greatly appreciate the information provided.

As we see today, the admin purges all old archives, destroying all helpful historical information. This means that previously solved issues will keep cropping up in perpetuity. So "The Pro/Con of Vtec has been beaten to death here for the last 14 years " is irrelevant since people join this forum every single day and the 5th gen market is still very active. I've been here a very short while, and my first bike is a '99. Do you think that just maybe I come here for information about my bike?

I am astounded at the criticism of the poster. If one ignored his post and read only your responses you'd think that he insulted your mothers. Ironically given your responses, the first thing an objective observer would think is that that everyone who owns VTEC feels emotionally fragile due to their bike being a step in the wrong direction and has to personally defend it, where no defense is otherwise needed, as though someone questioned their manhood. On your own behalf, you critics would have been better off ignoring this thread than sharing those thoughts.

BiKenG

I already explained why I asked the question and already thanked Dutchy for his information which is all I wanted. Try reading instead of trying to start an argument.

Actually you didnt address Davids question as to the point of why you wanted the comparison, are you looking to buy either model? BP also makes a good point , why not rely on private correspondence? Really seems that you had another agenda here. Have you ridden a 6 th gen for any duration? Your comments went way beyond just a constructive criticism to the realm of disparaging remarks that publicly trashed the bike in front of a group of its faithful owners while showing absolutely no social sensitivity. Respectfully Ken , whatever the point you may feel about its faults - I personally do not think you are qualified to make it here.

The "private correspondence" that Swithcblade suggested cannot happen when the thread was started to ask if anyone had the data. Later, after Dutchy posted the graph that the OP was looking for, the thread was just like a good post ride discussion with the topic evolving a bit and everyone related their personal experience on the most recent comment.

I think most people know that the complexity, weight and onerous valve adjustments when compared to systems that do not have it make the Vtec the modern equivalent of the 16" front wheel size that Honda wanted to hang on to for too long just because it was their idea and in theory it is a positive.

I am not even going to discuss the loss of the ultra reliable gear driven cams vs cam chain tensioners as I don't want to cloud the point that Vtec, AS IMPLEMENTED ON THE VFR (not the same as their cars) is a net negative (or if you are an ardent supporter you would argue for net neutral) technology.

Many may reply that the Vtec transition is not an issue and that is the point. Dutchy's graph shows that by the time the other 2 valves per cylinder open the bike is struggling for air so much that the power has dropped and the opening is just a little more noise as the engine plays catch up from Vtec opening to 9k rpm or so. That is a big hole from 5-9k in the torque curve when compared to the previous power plant.

No intent to bash any other VFR owners just a question to Honda as to why they continue to push the bike version of Vtec...

I think it goes without question that the VTEC transition should occur earlier. Just the change in 06 improved the feel of the system on 6th gen bikes. I honestly think that the implementation of VTEC that they used in these bikes was a bit, meh. It's an efficiency oriented system, rather than performance oriented, and unfortunately that does show in the power curve. I know this isn't a CBR or anything like that, but it's still a sportbike. Why is Honda using a system that they developed for commuter cars on this?

That having been said, I love my 6th gen, and I'll continue to feel that way, and I wouldn't want another bike for daily use.

V-tec sounds impressive when you explain it to non-moto related people but I'm pretty sure it comes from emission related attempts at advancements and would prefer to have a more linear dyno result.

CornerCarver

The "private correspondence" that Swithcblade suggested cannot happen when the thread was started to ask if anyone had the data. Later, after Dutchy posted the graph that the OP was looking for, the thread was just like a good post ride discussion with the topic evolving a bit and everyone related their personal experience on the most recent comment.

I think most people know that the complexity, weight and onerous valve adjustments when compared to systems that do not have it make the Vtec the modern equivalent of the 16" front wheel size that Honda wanted to hang on to for too long just because it was their idea and in theory it is a positive.

I am not even going to discuss the loss of the ultra reliable gear driven cams vs cam chain tensioners as I don't want to cloud the point that Vtec, AS IMPLEMENTED ON THE VFR (not the same as their cars) is a net negative (or if you are an ardent supporter you would argue for net neutral) technology.

Many may reply that the Vtec transition is not an issue and that is the point. Dutchy's graph shows that by the time the other 2 valves per cylinder open the bike is struggling for air so much that the power has dropped and the opening is just a little more noise as the engine plays catch up from Vtec opening to 9k rpm or so. That is a big hole from 5-9k in the torque curve when compared to the previous power plant.

No intent to bash any other VFR owners just a question to Honda as to why they continue to push the bike version of Vtec...

Switchblade

[image: 01-02vfrdyno.jpg]

I believe the chart I posted is more representative of the two bikes VTEC I have riden.

I dont see any problems with the "VTEC TRANSITION" in my graph or the two VTEC's I have ridden.

[image: VTEC_Open.jpg]

As far as the pic it is of a 1989 Integra VTEC the adjusting back lash assembly is the dead give away.

Switchblade

[image: VTEC_Open.jpg]

As far as the pic it is of a 1989 Integra VTEC the adjusting back lash assembly is the dead give away.

And the Vtech for the cars is nothing like the Vtec for the bikes...completely different as there is no "variable" in the valve timing.

CornerCarver

as far as the pic it is of a 1989 Integra VTEC the adjusting back lash assembly is the dead give away.

A dead giveaway for anyone with an '89 Integra VTEC....

01-02vfrdyno.jpg

am I missing something the 01 is non vtec correct? how do you say the vtec causes a slump in power? they are so very close in power the entire rpm range. it looks like the 02 is down what 2HP at 6500rpm just before vtec. I know everyone is expert riders and everything and can feel the difference .1 HP makes but that little bit of HP difference does not make vtec a bad concept.

I have ridden 3rd gens 4th gens 5th gens and several 6 gens, the tuned 3rd and 4th gens are just bad ass and fun as hell. not to give 5th gen owners a hard time but they just felt meh to me. not a bad bike I mean hell its a vfr, just did not do it for me. the 6 gens though, they just fit me better and I LOVE the vtec, would not want it any other way.

just my 2 cents take it with a grain of salt

CornerCarver

I think most people know that the complexity, weight and onerous valve adjustments when compared to systems that do not have it make the Vtec the modern equivalent of the 16" front wheel size that Honda wanted to hang on to for too long just because it was their idea and in theory it is a positive.

I am not even going to discuss the loss of the ultra reliable gear driven cams vs cam chain tensioners as I don't want to cloud the point that Vtec, AS IMPLEMENTED ON THE VFR (not the same as their cars) is a net negative (or if you are an ardent supporter you would argue for net neutral) technology.

Many may reply that the Vtec transition is not an issue and that is the point. Dutchy's graph shows that by the time the other 2 valves per cylinder open the bike is struggling for air so much that the power has dropped and the opening is just a little more noise as the engine plays catch up from Vtec opening to 9k rpm or so. That is a big hole from 5-9k in the torque curve when compared to the previous power plant.

No intent to bash any other VFR owners just a question to Honda as to why they continue to push the bike version of Vtec...

Switchblade

[image: 01-02vfrdyno.jpg]

I believe the chart I posted is more representative of the two bikes VTEC I have riden.

I dont see any problems with the "VTEC TRANSITION" in my graph or the two VTEC's I have ridden.

After this we can talk about what oil is best!

Alaskan

After this we can talk about what oil is best!

Or maybe even tires........;)

Dutchy

Et voila!

[image: IM000015.jpg]

3dcycle

01-02vfrdyno.jpg

am I missing something the 01 is non vtec correct? how do you say the vtec causes a slump in power? they are so very close in power the entire rpm range. it looks like the 02 is down what 2HP at 6500rpm just before vtec. I know everyone is expert riders and everything and can feel the difference .1 HP makes but that little bit of HP difference does not make vtec a bad concept.

I have ridden 3rd gens 4th gens 5th gens and several 6 gens, the tuned 3rd and 4th gens are just bad ass and fun as hell. not to give 5th gen owners a hard time but they just felt meh to me. not a bad bike I mean hell its a vfr, just did not do it for me. the 6 gens though, they just fit me better and I LOVE the vtec, would not want it any other way.

just my 2 cents take it with a grain of salt

CornerCarver

I think most people know that the complexity, weight and onerous valve adjustments when compared to systems that do not have it make the Vtec the modern equivalent of the 16" front wheel size that Honda wanted to hang on to for too long just because it was their idea and in theory it is a positive.

I am not even going to discuss the loss of the ultra reliable gear driven cams vs cam chain tensioners as I don't want to cloud the point that Vtec, AS IMPLEMENTED ON THE VFR (not the same as their cars) is a net negative (or if you are an ardent supporter you would argue for net neutral) technology.

Many may reply that the Vtec transition is not an issue and that is the point. Dutchy's graph shows that by the time the other 2 valves per cylinder open the bike is struggling for air so much that the power has dropped and the opening is just a little more noise as the engine plays catch up from Vtec opening to 9k rpm or so. That is a big hole from 5-9k in the torque curve when compared to the previous power plant.

No intent to bash any other VFR owners just a question to Honda as to why they continue to push the bike version of Vtec...

Switchblade

[image: 01-02vfrdyno.jpg]

I believe the chart I posted is more representative of the two bikes VTEC I have riden.

I dont see any problems with the "VTEC TRANSITION" in my graph or the two VTEC's I have ridden.

There is some speculation regarding what you are getting from the 6G vs 5G engine outputs.

The chart that Dutchy posted from a noted magazine shows a marked difference in torque output from 5-9k rpm between not only the 5G and 6G but with the 3/4G also out-pacing it in torque.

I am not sure of the origin of the chart Switchblade posted but it is not uncommon for a "ringer" to be supplied for magazine testing or when a manufacturer knows their bike will be put on the dyno.

I have ridden only about 13-15 6G VFR's and the hole in the torque is less apparent on some individual bikes compared to others so it is possible that both charts are accurate.

The throttle snatchiness at low RPMs is not a characteristic of Vtec but of many fuel injected bikes. They behave this way when programmed to meet EPA emissions standards but it may be exacerbated by the fact that Honda have closed two valves per cylinder to increase the speed of the intake charge.

CornerCarver

CornerCarver

as far as the pic it is of a 1989 Integra VTEC the adjusting back lash assembly is the dead give away.

A dead giveaway for anyone with an '89 Integra VTEC....

Or anyone who has slimmed there VFR800 VTEC valves.

3dcycle

01-02vfrdyno.jpg

am I missing something the 01 is non vtec correct? how do you say the vtec causes a slump in power? they are so very close in power the entire rpm range. it looks like the 02 is down what 2HP at 6500rpm just before vtec. I know everyone is expert riders and everything and can feel the difference .1 HP makes but that little bit of HP difference does not make vtec a bad concept.

I have ridden 3rd gens 4th gens 5th gens and several 6 gens, the tuned 3rd and 4th gens are just bad ass and fun as hell. not to give 5th gen owners a hard time but they just felt meh to me. not a bad bike I mean hell its a vfr, just did not do it for me. the 6 gens though, they just fit me better and I LOVE the vtec, would not want it any other way.

just my 2 cents take it with a grain of salt

I think most people know that the complexity, weight and onerous valve adjustments when compared to systems that do not have it make the Vtec the modern equivalent of the 16" front wheel size that Honda wanted to hang on to for too long just because it was their idea and in theory it is a positive.

I am not even going to discuss the loss of the ultra reliable gear driven cams vs cam chain tensioners as I don't want to cloud the point that Vtec, AS IMPLEMENTED ON THE VFR (not the same as their cars) is a net negative (or if you are an ardent supporter you would argue for net neutral) technology.

Many may reply that the Vtec transition is not an issue and that is the point. Dutchy's graph shows that by the time the other 2 valves per cylinder open the bike is struggling for air so much that the power has dropped and the opening is just a little more noise as the engine plays catch up from Vtec opening to 9k rpm or so. That is a big hole from 5-9k in the torque curve when compared to the previous power plant.

No intent to bash any other VFR owners just a question to Honda as to why they continue to push the bike version of Vtec...

[image: 01-02vfrdyno.jpg]

I believe the chart I posted is more representative of the two bikes VTEC I have riden.

I dont see any problems with the "VTEC TRANSITION" in my graph or the two VTEC's I have ridden.

I agree and I will never believe Honda did it for emissions.

Chill pill time.

I've done nearly 130,000 miles on a 5th Gen and nearly 70,000 miles on a 6th Gen so I feel reasonably qualified here;

The 5th Gen has the best engine - for smooth, progressive torque, ease of servicing and a pretty unique noise.

The 6th Gen does everything else better BUT the engine. It simply isn't as nice...less torque which is where most of us ride anyway, though the aggressiveness in the 4-valve range is pleasing, it's more complex to service and probably (slightly) less reliable overall.

I've never ridden an earlier Gen.

The 8th Gen does a bloody good job of mixing the 5th & 6th Gens. It's as close to a 5th Gen engine yr likely to get whilst still having the Vtec system yet it has superior handling and more modern ergonomics than the 6th Gen. The best of both worlds? Not a classic (yet) like the 5th Gen, but a brilliant bike to ride nonetheless....admittedly only from a test ride.

The 7th Gen....well, where do I start? Sublimely powerful engine (even without a flashed ECU) and with some good money spent on suspension it handles as well as my 6th Gen with its fettled rear end.

I've had all 3 (5/6/7) in the garage at once and every time I walked in, I wanted to ride the 7th! A bit off topic at the end there, but at least it's all VFRs, every one of them loveable!

Of course this is just my opinion, and as it is an opinion, you cannot argue it, because it is my opinion.

Cheers all. :beer: :491:

It's amazing how both graphs show the 6th gen with more torque BUT when they hit asphalt the 6th gen loses the torque.

Switchblade

It's amazing how both graphs show the 6th gen with more torque BUT when they hit asphalt the 6th gen loses the torque.

Both charts show the 5G with more torque but the 6G with peak torque occurring higher in the rev range, thereby making more peak horsepower (at least on the magazine chart from Dutchy).

The peak HP differences on your chart are so negligible as to be statistically insignificant or can be due to the ambient temp changes in the same hour on the same dyno.

We are all very passionate about the VFR. And rightly so....it's legendary. However, there is no 2016 model in Honda's lineup and they are offering a $1,500 discount for the leftover 2014's. There are new 2014's on eBay for $7,999. The sales are no longer there. What will the future be for the VFR/Interceptor? IMO, a low-tech mass production RC-213V with VFR ergonomics and some retro styling touches would turn it around for Honda. There'd be a waiting list.

Alaskan

After this we can talk about what oil is best!

Oh yea baby... a good oil thread should challenge your beliefs...

no vfr this year is because we are all retarded, didn't you get the memo you should be buying a Africa twin... lol the least they could do is give us the vfr800x

BusyLittleShop

Alaskan

After this we can talk about what oil is best!

Oh yea baby... a good oil thread should challenge your beliefs...

Less friction on the VTEC valves right Larry .

I guess the 6th gen had 20,000 mile Quake State oil in it during the dyno test.

Switchblade

Less friction on the VTEC valves right Larry .

Right... picking an oil is like picking a girl friend... thin is in!!!

[image: 10702996-Illustration-of-pretty-girl-bef]

Honda UK 2002 Press Pack for the VFR, take from it what you will.

http://www.hoc.org.uk/gallery/press/2002/2002_VFR.pdf

I'd like to challenge the notion that the fifth gen is as quiet bike as the sixth gen. It is not even close. And the exhaust is not the biggest contributor. I would bet that if one were riding in a car with the window open next to a fifth at 6500+ rpm most people with good hearing would find it intolerable. Add in the phone users and radio listener it would be worse. The exhaust makes a good contribution also when under load at near-wide-open throttle.

I have a stock exhaust on a 2001. When I ride down the highway I observe the following nearly universally: (all RPMs measured in sixth gear)

4,000 rpm - following vehicles behave normal following distances;

5,000 rpm - they begin falling back or try to pass quickly

6,000 rpm - they are seldom within several hundred yards unless they are hell bent on getting in front of the noise and trying aggressively passing

7000 rpm and up - the following traffic tends to fall back to nearly out-of-sight

Now I suppose it is possible that, a couple hours after taking my shower and getting sweaty under my leathers, I smell bad, but I doubt that. :)

Does anyone else observe anything similar with their fifth?

MaxSwell

I'd like to challenge the notion that the fifth gen is as quiet bike as the sixth gen. It is not even close. And the exhaust is not the biggest contributor. I would bet that if one were riding in a car with the window open next to a fifth at 6500+ rpm most people with good hearing would find it intolerable. Add in the phone users and radio listener it would be worse. The exhaust makes a good contribution also when under load at near-wide-open throttle.

I have a stock exhaust on a 2001. When I ride down the highway I observe the following nearly universally: (all RPMs measured in sixth gear)

4,000 rpm - following vehicles behave normal following distances;

5,000 rpm - they begin falling back or try to pass quickly

6,000 rpm - they are seldom within several hundred yards unless they are hell bent on getting in front of the noise and trying aggressively passing

7000 rpm and up - the following traffic tends to fall back to nearly out-of-sight

Now I suppose it is possible that, a couple hours after taking my shower and getting sweaty under my leathers, I smell bad, but I doubt that. :)

Does anyone else observe anything similar with their fifth?

Terry, without a control group it could just as readily be assumed that the normal sort of drivers to be around you at 4,000 rpm in 6th gear on a 5G are slower more cautious drivers and when you are at 5k you begin to out pace those drivers.

By the time your speed equates to 6k you are "between groups" in driving classification and you are leaving others but the drivers who are hell bent on getting around you may just be drivers who normally travel at 20 over or are late for something.

By 7k you are throwing caution to the wind and everyone is using you as their "rabbit" to flush out the LEO's....My glass is always half full so grain of salt. :wink:

Given that it is not the most ideal measurement device, almost every smartphone on the market has a decibel meter application. This should be easy enough to solve in a nice empty parking lot IF we can find owners of a 5th and 6th gen with stock exhausts and the same smartphone (maybe impossible?). Place the phone in the same orientation at a set distance from the bike and take readings every 500 rpms. Any volunteers?

Mohawk

Honda UK 2002 Press Pack for the VFR, take from it what you will.

http://www.hoc.org.uk/gallery/press/2002/2002_VFR.pdf

CornerCarver

MaxSwell

Terry, without a control group it could just as readily be assumed that the normal sort of drivers to be around you at 4,000 rpm in 6th gear on a 5G are slower more cautious drivers and when you are at 5k you begin to out pace those drivers.

By the time your speed equates to 6k you are "between groups" in driving classification and you are leaving others but the drivers who are hell bent on getting around you may just be drivers who normally travel at 20 over or are late for something.

By 7k you are throwing caution to the wind and everyone is using you as their "rabbit" to flush out the LEO's....My glass is always half full so grain of salt. :wink:

CC,

On my machine, 4,000 rpm is ~ 60 mph (indicated) (I calculate indicated speeds are between 8% and 9% too high) ;

5,000 ~ 70 indicated (gps says 64mph);

6,000 ~ 80 indicated (on a 70 mph speed limit freeway, if I'm doing indicated 80 mph, I'm being passed by just about everyone; I'm just keeping up.)

So, while you may be partially correct CC, I doubt that eliminates the noise from the primary cause of the observed behavior.

I think Honda a excellent job !!!

And thanks Mohawk for the material >>> ....

Switchblade

Mohawk

Honda UK 2002 Press Pack for the VFR, take from it what you will.

http://www.hoc.org.uk/gallery/press/2002/2002_VFR.pdf

"Take its renowned, high-powered V4 engine for a start. No longer simply a high-revving powerhouse, it’s been lightened with a new chain-driven camtrain and recharged with a unique new 2-stage valve control system, called ‘V4 VTEC,’ that combines the most effective power characteristics of 2-valve and 4-valve engine design in one remarkable unit." Really !! "VFR reborn as a more dynamic and formidable sports tourer, this unique, high-performance V4 engine was completely revised to achieve a stronger surge of low-to-midrange power output coupled with the added benefits of lower noise and lower emissions, all while maintaining the VFR’s traditional Honda V4 power characteristics." This is a Honda press release. :"Until now, the VFR’s most impressive power output has been of the highrevving 4-valve variety. But with the introduction of its revolutionary new V4 VTEC system, the new VFR’s engine delivers stronger, more responsive torque and power output at low-to-midrange engine speeds, and then switches valve operation at higher engine speeds to deliver a breathtaking leap of Super Sport performance. Amazingly enough, this major boost in total performance was achieved without the slightest change to its bore, stroke, throttle bore, crankshaft or other internal engine specifications." Well Well !!!

Spoken like someone who knows what he's talking about. I agree completely.

BTW: I owned two Integra GSRs, the first generation (1994) and the last generation (2001) (stolen from my driveway in 2005 - Bastages!). Fabulous machines and best ones I've ever owned. Not the same VTEC as the motorcycles.

"80Nm/8,750min-1 (95/1/EC)"

Switchblade

"80Nm/8,750min-1 (95/1/EC)"

Switch, can you explain for us non-engineer types?

80 Nm (59 ft-lbs) @ 8750 RPM per Directive 95/1/EC of the European Parliament and of the Council of February 2, 1995 on the Maximum Design Speed, Maximum Net Engine Power of Two- or Three-wheel Motor Vehicles.

MadScientist

80 Nm (59 ft-lbs) @ 8750 RPM per Directive 95/1/EC of the European Parliament and of the Council of February 2, 1995 on the Maximum Design Speed, Maximum Net Engine Power of Two- or Three-wheel Motor Vehicles.

Yeh what he wrote ^^^ Now if he could convert that to SAE ..

Switchblade

"The purpose of the VTEC system on the Interceptor, of course, is a broadening of the power curve. Operation on two valves per cylinder at lower rpm levels increases power and torque, while operation on four valves per cylinder at higher rpm levels increases horsepower and torque. Most engines must be tuned to compromise power at one (or both) extremes of the rpm range. With VTEC, the Interceptor does not have to accept this compromise. "

Switchblade

RobF

If Ken will forgive a bit more friendly argument about the rationale for VTEC...

We have two alternative theories in play here:

#1) VTEC was introduced as a performance enhancement

#2) VTEC was introduced as a flawed(?) response to stricter regulation

Now I don't have any real evidence and I've read hardly any industry press over the past twenty years, so I am a poor historian. Still, I can't quite bite on theory #1. To my mind, the decisive evidence against theory #1 is the almost total lack of actual performance improvement. Other than some small gains at the very top of the HP curve, the VTEC mill fails to improve upon the 5th Gen and, worse, it pays for this lack of improvement with an unsettling notch in the middle of the power curve and troublesome valve maintenance.

I'm prepared to lay any of the usual corporate sins at Honda's feet: misreading the market, being short-sighted, etc. But I can't bring myself to believe they don't understand motorcycles or aren't competent engineers. They saw then the same power curve comparisons we see now.

I have seen the marketing blurbs Switchblade posted. I see the way that bolsters theory #1. In my mind, I file that under "the marketing department being the marketing department". They will always put the best possible spin on a development regardless of whether or not that spin reflects the actual history of that development.

I guess if I really wanted to move this beyond coffee house speculation, I would have to research whether or not any significant new regulations were actually introduced around 2002. It could have been later than that, as Honda would need to anticipate the full life of the 6h Gen.

I never quote anything from "Honda" .

Just to be clear .

RobF

Switchblade

I never quote anything from "Honda" .

Just to be clear .

Fair enough. I saw this:

Switchblade

"The purpose of the VTEC system on the Interceptor, of course, is a broadening of the power curve. Operation on two valves per cylinder at lower rpm levels increases power and torque, while operation on four valves per cylinder at higher rpm levels increases horsepower and torque. Most engines must be tuned to compromise power at one (or both) extremes of the rpm range. With VTEC, the Interceptor does not have to accept this compromise. "

...in quotation marks earlier in the thread and assumed it was some bit of marketing-ese from Honda (maybe a second-hand quotation passed along via industry journalists) back when the VTEC VFR was being rolled out.

Switchblade

Mohawk

Honda UK 2002 Press Pack for the VFR, take from it what you will.

http://www.hoc.org.uk/gallery/press/2002/2002_VFR.pdf

"Take its renowned, high-powered V4 engine for a start. No longer simply a high-revving powerhouse, it’s been lightened with a new chain-driven camtrain and recharged with a unique new 2-stage valve control system, called ‘V4 VTEC,’ that combines the most effective power characteristics of 2-valve and 4-valve engine design in one remarkable unit." Really !! "VFR reborn as a more dynamic and formidable sports tourer, this unique, high-performance V4 engine was completely revised to achieve a stronger surge of low-to-midrange power output coupled with the added benefits of lower noise and lower emissions, all while maintaining the VFR’s traditional Honda V4 power characteristics." This is a Honda press release. :"Until now, the VFR’s most impressive power output has been of the highrevving 4-valve variety. But with the introduction of its revolutionary new V4 VTEC system, the new VFR’s engine delivers stronger, more responsive torque and power output at low-to-midrange engine speeds, and then switches valve operation at higher engine speeds to deliver a breathtaking leap of Super Sport performance. Amazingly enough, this major boost in total performance was achieved without the slightest change to its bore, stroke, throttle bore, crankshaft or other internal engine specifications." Well Well !!!

Switchblade The most revolutionary development in the VFR’s new engine is the introduction of a revolutionary new two-stage ‘V4 VTEC’ valve control system which combines the best power characteristics of both 2-valve and 4-valve combustion chamber designs. Basically, this highly effective new system keeps the engine running on two valves per cylinder at low to midrange engine speeds in order to maximise the engine’s thrust of smooth, strong low-end torque, then switches to full 4-valve operation at higher engine speeds to take advantage of this configuration’s high-rev power characteristics, thus achieving the best of both worlds of engine design. The new VFR’s unique V4 VTEC system features a set of compact, hydraulically actuated lifter sleeves installed inside the inverted buckets of the valvetrain’s direct-actuation valve lifters, over one intake valve and one exhaust valve in each cylinder. During low-to-midrange operation, the lifter sleeves slide benignly up and down over the tops of the valve stems, allowing only two valves in each cylinder to open to maintain the enhanced torque and powerful thrust of responsive low-end power and acceleration associated with the best 2-valve engines. At around 7,000rpm the entire personality of the engine suddenly changes, as a burst of oil pressure to the lifter sleeves forces their spring-loaded engagement pins to slide across the centre hole and initiate actuation of the remaining two valves of each cylinder. The effect of this changeover is breathtaking, as the engine suddenly comes on cam, full 4-valve operation kicks in, and the tachometer needle takes a dramatic leap toward redline in the characteristic rush of high-rev power commonly associated with the most high-performance 4-valve 4-stroke engines. In achieving the best of both worlds of 4-stroke engine design, the V4 VTEC In achieving the best of both worlds of 4-stroke engine design, the V4 VTEC system also gives a further boost to the VFR’s midrange performance to provide a more linear surge of acceleration that seems to instantly jump in response to throttle input from virtually anywhere in the rev range, rather than building up slowly to a conventional 4-valve engine’s peak powerproducing revs. One unmistakable result of this new 2-stage power output is the exceptional roll-on performance the new VFR delivers at the twist of its throttle—even when fully loaded for touring with passenger and gear.

I think Honda a excellent job !!!

And thanks Mohawk for the material >>> ....

This is rich.

For the first part that I bolded, I bet a good marketing guy could make some people believe in the tooth fairy. I have never experienced a vtec transition that was breathtaking even with that large dip engineered into the torque curve.

And the second bolded section must be the reason so many 6G guys drop a tooth on the front sprocket even after Mother Honda already did this in addition to revising the gearing in 1-3 gears to make the "seem to instantly jump in response to throttle input"...

Switchblade

MadScientist

80 Nm (59 ft-lbs) @ 8750 RPM per Directive 95/1/EC of the European Parliament and of the Council of February 2, 1995 on the Maximum Design Speed, Maximum Net Engine Power of Two- or Three-wheel Motor Vehicles.

Yeh what he wrote ^^^ Now if he could convert that to SAE ..

That is converted to SAE 59 ft-lbs of torque at 8750 RPM is the agreed upon limit for that EC directive.

Knight

BiKenG asked for numbers between two bikes which is a perfectly valid and objective question. The bikes are both VFRs so one would think the question is acceptable for a...........VFR FORUM! By the way, I greatly appreciate the information provided.

As we see today, the admin purges all old archives, destroying all helpful historical information. This means that previously solved issues will keep cropping up in perpetuity. So "The Pro/Con of Vtec has been beaten to death here for the last 14 years " is irrelevant since people join this forum every single day and the 5th gen market is still very active. I've been here a very short while, and my first bike is a '99. Do you think that just maybe I come here for information about my bike?

I am astounded at the criticism of the poster. If one ignored his post and read only your responses you'd think that he insulted your mothers. Ironically given your responses, the first thing an objective observer would think is that that everyone who owns VTEC feels emotionally fragile due to their bike being a step in the wrong direction and has to personally defend it, where no defense is otherwise needed, as though someone questioned their manhood. On your own behalf, you critics would have been better off ignoring this thread than sharing those thoughts.

Your points are actually very valid. I guess as a mod here my thoughts are tainted from all the US/Them post about the subject over the last decade plus that got ugly and i had to moderate them.

I also forget that most all of those threads have been purged long ago, but I remember them like it was yesterday because it was Viffer brother against viffer brother. Oh the pain of it!

So I apologize to anyone I may have offended. :sleep:

It just has always bothered me when members say one VFR model sux compared to another. I would say just about 100% of the folks here ride a VFR of some form or model and we love each and every one of them and if you dog one model you dog a large number of members as well.

The worst one's were members who had never even ridden a vtec, but trashed them completely based on someone else's opinion. :wacko:

Flame On!

Just like almost every other thread about Pros & Cons of Vtec the posts are getting heated and people are taking offense.

BTW Vtec's are set-up extremely Lean(again for emissions) and have smaller tube headers that started on all Cat equipped VFR's(again emissions) from 00-on.

I think if you fed the same fuel levels and larger exhaust of the 98-99 VFR you would have a much cleaner comparo of power levels and delivery.

CornerCarver

Switchblade

"The purpose of the VTEC system on the Interceptor, of course, is a broadening of the power curve. Operation on two valves per cylinder at lower rpm levels increases power and torque, while operation on four valves per cylinder at higher rpm levels increases horsepower and torque. Most engines must be tuned to compromise power at one (or both) extremes of the rpm range. With VTEC, the Interceptor does not have to accept this compromise. "

Switchblade

RobF

If Ken will forgive a bit more friendly argument about the rationale for VTEC...

We have two alternative theories in play here:

#1) VTEC was introduced as a performance enhancement

#2) VTEC was introduced as a flawed(?) response to stricter regulation

Now I don't have any real evidence and I've read hardly any industry press over the past twenty years, so I am a poor historian. Still, I can't quite bite on theory #1. To my mind, the decisive evidence against theory #1 is the almost total lack of actual performance improvement. Other than some small gains at the very top of the HP curve, the VTEC mill fails to improve upon the 5th Gen and, worse, it pays for this lack of improvement with an unsettling notch in the middle of the power curve and troublesome valve maintenance.

I'm prepared to lay any of the usual corporate sins at Honda's feet: misreading the market, being short-sighted, etc. But I can't bring myself to believe they don't understand motorcycles or aren't competent engineers. They saw then the same power curve comparisons we see now.

I have seen the marketing blurbs Switchblade posted. I see the way that bolsters theory #1. In my mind, I file that under "the marketing department being the marketing department". They will always put the best possible spin on a development regardless of whether or not that spin reflects the actual history of that development.

I guess if I really wanted to move this beyond coffee house speculation, I would have to research whether or not any significant new regulations were actually introduced around 2002. It could have been later than that, as Honda would need to anticipate the full life of the 6h Gen.

I never quote anything from "Honda" .

Just to be clear .

RobF

Switchblade

I never quote anything from "Honda" .

Just to be clear .

Fair enough. I saw this:

Switchblade

"The purpose of the VTEC system on the Interceptor, of course, is a broadening of the power curve. Operation on two valves per cylinder at lower rpm levels increases power and torque, while operation on four valves per cylinder at higher rpm levels increases horsepower and torque. Most engines must be tuned to compromise power at one (or both) extremes of the rpm range. With VTEC, the Interceptor does not have to accept this compromise. "

...in quotation marks earlier in the thread and assumed it was some bit of marketing-ese from Honda (maybe a second-hand quotation passed along via industry journalists) back when the VTEC VFR was being rolled out.

Switchblade

Mohawk

Honda UK 2002 Press Pack for the VFR, take from it what you will.

http://www.hoc.org.uk/gallery/press/2002/2002_VFR.pdf

"Take its renowned, high-powered V4 engine for a start. No longer simply a high-revving powerhouse, it’s been lightened with a new chain-driven camtrain and recharged with a unique new 2-stage valve control system, called ‘V4 VTEC,’ that combines the most effective power characteristics of 2-valve and 4-valve engine design in one remarkable unit." Really !! "VFR reborn as a more dynamic and formidable sports tourer, this unique, high-performance V4 engine was completely revised to achieve a stronger surge of low-to-midrange power output coupled with the added benefits of lower noise and lower emissions, all while maintaining the VFR’s traditional Honda V4 power characteristics." This is a Honda press release. :"Until now, the VFR’s most impressive power output has been of the highrevving 4-valve variety. But with the introduction of its revolutionary new V4 VTEC system, the new VFR’s engine delivers stronger, more responsive torque and power output at low-to-midrange engine speeds, and then switches valve operation at higher engine speeds to deliver a breathtaking leap of Super Sport performance. Amazingly enough, this major boost in total performance was achieved without the slightest change to its bore, stroke, throttle bore, crankshaft or other internal engine specifications." Well Well !!!

Switchblade The most revolutionary development in the VFR’s new engine is the introduction of a revolutionary new two-stage ‘V4 VTEC’ valve control system which combines the best power characteristics of both 2-valve and 4-valve combustion chamber designs. Basically, this highly effective new system keeps the engine running on two valves per cylinder at low to midrange engine speeds in order to maximise the engine’s thrust of smooth, strong low-end torque, then switches to full 4-valve operation at higher engine speeds to take advantage of this configuration’s high-rev power characteristics, thus achieving the best of both worlds of engine design. The new VFR’s unique V4 VTEC system features a set of compact, hydraulically actuated lifter sleeves installed inside the inverted buckets of the valvetrain’s direct-actuation valve lifters, over one intake valve and one exhaust valve in each cylinder. During low-to-midrange operation, the lifter sleeves slide benignly up and down over the tops of the valve stems, allowing only two valves in each cylinder to open to maintain the enhanced torque and powerful thrust of responsive low-end power and acceleration associated with the best 2-valve engines. At around 7,000rpm the entire personality of the engine suddenly changes, as a burst of oil pressure to the lifter sleeves forces their spring-loaded engagement pins to slide across the centre hole and initiate actuation of the remaining two valves of each cylinder. The effect of this changeover is breathtaking, as the engine suddenly comes on cam, full 4-valve operation kicks in, and the tachometer needle takes a dramatic leap toward redline in the characteristic rush of high-rev power commonly associated with the most high-performance 4-valve 4-stroke engines. In achieving the best of both worlds of 4-stroke engine design, the V4 VTEC In achieving the best of both worlds of 4-stroke engine design, the V4 VTEC system also gives a further boost to the VFR’s midrange performance to provide a more linear surge of acceleration that seems to instantly jump in response to throttle input from virtually anywhere in the rev range, rather than building up slowly to a conventional 4-valve engine’s peak powerproducing revs. One unmistakable result of this new 2-stage power output is the exceptional roll-on performance the new VFR delivers at the twist of its throttle—even when fully loaded for touring with passenger and gear.

I think Honda a excellent job !!!

And thanks Mohawk for the material >>> ....

This is rich.

For the first part that I bolded, I bet a good marketing guy could make some people believe in the tooth fairy. I have never experienced a vtec transition that was breathtaking even with that large dip engineered into the torque curve.

And the second bolded section must be the reason so many 6G guys drop a tooth on the front sprocket even after Mother Honda already did this in addition to revising the gearing in 1-3 gears to make the "seem to instantly jump in response to throttle input"...

Switchblade

MadScientist

80 Nm (59 ft-lbs) @ 8750 RPM per Directive 95/1/EC of the European Parliament and of the Council of February 2, 1995 on the Maximum Design Speed, Maximum Net Engine Power of Two- or Three-wheel Motor Vehicles.

Yeh what he wrote ^^^ Now if he could convert that to SAE ..

That is converted to SAE 59 ft-lbs of torque at 8750 RPM is the agreed upon limit for that EC directive.

Sorry it does fit YOUR description.

I mite add I have ridden what i would call the best example of a modified 5th gen . Grif's 5th gen is truly a master piece. The performance parts make it a accelerate hard and now he has upgraded the suspension it is now a total package.

I love all Viffers. The biggest issue outside of which gen you bought is the fact you bought one. Spoils you entirely for anything else. :-)

Dave

dgordon

I love all Viffers. The biggest issue outside of which gen you bought is the fact you bought one. Spoils you entirely for anything else. :-)

Dave

Who are you writing to, if its me you need to read the post your posting in .

Dave too. :(

[image: post-301-0-70020600-1456197840.jpg]

[image: post-301-0-43012700-1456197913.jpg]

:beer:

I do feel bad for BiKenG. We chased him out of his own thread, unfairly I think. I own exactly one motorcycle, a VTEC VFR, and still I believe pretty much the entirety of the thesis he posted back in #15

http://www.vfrdiscussion.com/forum/index.php/topic/82900-v-tec-advantage-or-not/?p=1028168

I love my 6th Gen, but if I could have the same 2005 ABS bike without the VTEC, I would trade in a heartbeat.

Anyway, I certainly didn't feel like he was trolling me, or anyone else for that matter.

Come back, Ken. We're sorry. Plus also, your return will be the perfect opportunity to admit that I was right all along about the emissions rationale for VTEC.

Here, I'll start your triumphant return post for you to save you the typing:

Friends, Romans, countrymen, lend me your ears. I've had time to really contemplate the deep wisdom, no, that won't do... the penetrating genius of RobF and the cogent analysis he shared back in post #6 which you've no doubt already bookmarked...

Having both a 5 Gen and 6 Gen, which I bought first, I enjoy both and find that I really enjoy the 6 gen for its intended purpose I bought it for, commuting/touring. Ironic all this VTEC negativity, as it was the VTEC engagement that threw a smile on my face when I did my test ride. I hit the freeway on ramp, twisted the throttle and BAM! hit that VTEC engagement point and I said SOLD!

I actually had the 6 Gen for almost 2 years before I decided I wanted a VFR just for play and figured the 5 Gen was the ticket. My main reason was for the GDCs and I liked the style of it too but ultimately it was because I didn't think having two of the exact same model made sense to me. Although the 5 Gen is more of my "play bike" I do find myself taking the 6 Gen out just for fun but the wife would prefer that I don't use it for that purpose as it was really meant to be my commuter (I.e. Don't crash it as that's your transportation to work!).

Although I do ride both quite often I sometimes grab the 6 Gen to run errands and maybe do some "exploratory rides" as it just seems to be so well suited to these task. I'll say this, it's hard for me to pick a winner here but VTEC or no VTEC I wouldn't trade either of these bikes right now!

3dcycle

01-02vfrdyno.jpg

am I missing something the 01 is non vtec correct? how do you say the vtec causes a slump in power? they are so very close in power the entire rpm range. it looks like the 02 is down what 2HP at 6500rpm just before vtec. I know everyone is expert riders and everything and can feel the difference .1 HP makes but that little bit of HP difference does not make vtec a bad concept.

I have ridden 3rd gens 4th gens 5th gens and several 6 gens, the tuned 3rd and 4th gens are just bad ass and fun as hell. not to give 5th gen owners a hard time but they just felt meh to me. not a bad bike I mean hell its a vfr, just did not do it for me. the 6 gens though, they just fit me better and I LOVE the vtec, would not want it any other way.

just my 2 cents take it with a grain of salt

CornerCarver

I think most people know that the complexity, weight and onerous valve adjustments when compared to systems that do not have it make the Vtec the modern equivalent of the 16" front wheel size that Honda wanted to hang on to for too long just because it was their idea and in theory it is a positive.

I am not even going to discuss the loss of the ultra reliable gear driven cams vs cam chain tensioners as I don't want to cloud the point that Vtec, AS IMPLEMENTED ON THE VFR (not the same as their cars) is a net negative (or if you are an ardent supporter you would argue for net neutral) technology.

Many may reply that the Vtec transition is not an issue and that is the point. Dutchy's graph shows that by the time the other 2 valves per cylinder open the bike is struggling for air so much that the power has dropped and the opening is just a little more noise as the engine plays catch up from Vtec opening to 9k rpm or so. That is a big hole from 5-9k in the torque curve when compared to the previous power plant.

No intent to bash any other VFR owners just a question to Honda as to why they continue to push the bike version of Vtec...

Switchblade

[image: 01-02vfrdyno.jpg]

I believe the chart I posted is more representative of the two bikes VTEC I have riden.

I dont see any problems with the "VTEC TRANSITION" in my graph or the two VTEC's I have ridden.

Since your posting dyno charts, I have added the NON- V-tec 7th Gen curves to show how much power you can make without a complicated valve-train. In fact, it only has one cam per bank....I guess the extra 438cc doesn't hurt either......I do miss the exhaust note and gear drive noises of the 3rd gen though......

[image: gallery_33430_7623_48071.jpg]

Well I just have to say that as soon as they get this in to product ,I'm parking the VFR.

[image: post-28191-0-93118500-1456207659.jpeg]

My first VTEC experience was disbelief... I traded rides with my brother Rich Merrill and whoa, I thought I was bumped from behind but it

was only a bump in the powerband... technically speaking if VTEC were an performance advantage Honda would have raced it... if you

wish to understand what Honda really knows about a smooth V4 power delivery then its the RC45 or the new RC213V-S...

Performance Bikes
"The RC45 motor feels like a VFR except with more of everything-acres of torque
and smooth power delivery. Basically the RC45 gives you it all- bottom end plod,
midrange drive and top end rush. after all the RC45 was inspired by the RVF-a hand
built Formula One missle."

Vaya Con Dios Rich...
[image: post-3131-0-93992400-1456206094.jpg]

Duc2V4

Having both a 5 Gen and 6 Gen, which I bought first, I enjoy both and find that I really enjoy the 6 gen for its intended purpose I bought it for, commuting/touring. Ironic all this VTEC negativity, as it was the VTEC engagement that threw a smile on my face when I did my test ride. I hit the freeway on ramp, twisted the throttle and BAM! hit that VTEC engagement point and I said SOLD!

There's the key everyone is dancing around, they did it because it would be fun.

Baileyrock

[image: attachicon.gif]copied pics 071.jpg

[image: attachicon.gif]lback-linkback.jpg

:beer:

The one they made more of and still produce today. VTEC.

Although not the question asked by the OP (wherever he went), I was dissatisfied with the VTEC transition on my 2004. A trip to the dynotuner fixed that, but at some cost in fuel efficiency, See attached. I know many 6th Gen owners don't mind the stock fueling, but as you can see my VFR had a horrible curve before the tune.

By the way, I use AMSOIL . . .

[image: dyno chart.JPG]

Switch, I am aware of the thread I posted to. :-) Just seemed some commentary contrary to VTEC. I love all the VFR's. ALL of them. Had to state it. Love the cam gears but also love the VTEC too. Imho, no bad generation of VFR. If I had my choice, I would have kept with the cam gears, but bikes are already SO expensive. The fact the VTEC's run on regular is a bonus, and run well they do. :-)

Cheers

Dave.

I had a little giggle the other day when I saw this Cadillac's license plate frame...Do you think he owns a 5 Gen too?! :goofy:

[image: post-23057-0-92637600-1456355157.jpg]

Or is laughing at all VTECs. LOL @ your VTEC!

dgordon

Switch, I am aware of the thread I posted to. :-) Just seemed some commentary contrary to VTEC. I love all the VFR's. ALL of them. Had to state it. Love the cam gears but also love the VTEC too. Imho, no bad generation of VFR. If I had my choice, I would have kept with the cam gears, but bikes are already SO expensive. The fact the VTEC's run on regular is a bonus, and run well they do. :-)

Cheers

Dave.

Me too and I dont post topic's that attempt to cause grief to anyone generation of VFR's.

That Dino chart with the VFR1200 overlayed is revealing. The 1200 has some power. Seems like the modern VFR should have 1000cc so HP can be 150+/-. Honda could do that today.....and without VTEC.

Dyno. Hate predictive text!!

A lot of "frequent posters" here complain about the power. I suspect that the "silent majority" of VFR owners are fine with ~100 hp. I know that I'll never need more power. I'm already a danger to myself. But I'm old. :lobby:

How many average VFR riders exploit even 80% of the capability of these fine machines? That is The question. Would Honda sell enough 150 hp VFRs. I know I'd not trust myself with a liter bike. A wrong twitch could be my last twitch.

YMMV

I know. Honda's philosophy has always been about balance unlike Kawasaki for instance which has always been about motor.

MaxSwell

Or is laughing at all VTECs. LOL @ your VTEC!

Well considering I was in my car, I'd have to say ALL VTECs!

MaxSwell A lot of "frequent posters" here complain about the power. I suspect that the "silent majority" of VFR owners are fine with ~100 hp. I know that I'll never need more power. I'm already a danger to myself. But I'm old. :lobby:

How many average VFR riders exploit even 80% of the capability of these fine machines? That is The question. Would Honda sell enough 150 hp VFRs. I know I'd not trust myself with a liter bike. A wrong twitch could be my last twitch.

YMMV [/fon

Lol, probably more truth in that then most of us would care to admitt to. I feel like I have the best of both worlds, my ZX9R fills in the gaps very nicely(162hp / 382 pds) even for a 15 yo bike! But I love my Honda. :)

MaxSwell

A lot of "frequent posters" here complain about the power. I suspect that the "silent majority" of VFR owners are fine with ~100 hp. I know that I'll never need more power. I'm already a danger to myself. But I'm old. :lobby:

How many average VFR riders exploit even 80% of the capability of these fine machines? That is The question. Would Honda sell enough 150 hp VFRs. I know I'd not trust myself with a liter bike. A wrong twitch could be my last twitch.

YMMV

Honestly the only time I need more power is when two up and passing or moving away from a situation caused by an inattentive driver.

Now I want more power when hooning around lofting a wheel and trying to slide the rear on corner exits without the aid of a wet damp paint stripe on the road.

The throttle by wire characteristics of such an animal would allow 2-4 preprogrammed settings for 'taming" the beast depending on factors.

I would be curious to see what the actual cost of the 6th gen engine is next to the 5th gen engine. From an engineering standpoint, I love the gear driven cams. Remember when Aprilia offered this as a very expensive upgrade for the RSV4 so they could run in Biaggi's WSBK? For me the VTEC offered a ton of complexity for no benefit.

I think nearly everyone missed the point on this thread. The VFR800 VTEC does not implement the traditional Honda performance VTEC, it actually implements a form of VTEC-E. Where the E stands for economy.

This is totally different than your typical Integra GSR or Civic SI VTEC system where you have a 3 lobe per cylinder (DOHC) or 5 lobe per cylinder (SOHC) camshaft that has a separate high and low lobe to combine the power characteristics of a race cam with the idle quality/clean emissions/low end torque and drivability of a small economy camshaft.

In VTEC-E, the primary benefit is to introduce a swirl in the combustion chamber that allows for a fast burn or otherwise know as "Lean Burn" combustion event. This is done for fuel economy purposes as lean burn heads can safely run up to about 20:1 air to fuel ratios while under light load and low RPMs. This is why the VFR VTEC has implemented an open loop fuel injection system that will go into closed loop mode under light steady throttle and low rpms. This is also why everyone complains of a surging effect at light steady throttle on the VFR VTEC. What you are feeling when your VFR VTEC is surging, is your bike running in closed loop lean burn, referring to the signal from the o2 sensors and the ecu leaning the air fuel ratio to the absolute limit (well over 15:1 air:fuel).

This is why when people disable their o2 sensors and add a power commander on a VFR VTEC, the added smoothness and low end torque is usually accompanied by a loss in MPGs (depending on habits and riding style).

It is my feeling, based on my research on various variations of variable valve implementations, that Honda made the VFR800 "VTEC" primarily do to it lowering emissions, lowering sound output and raising MPGs, but the marketing team decided that they could spin this in another direction to aid in sales. I feel like the marketing team decided to cash in on the VTEC name and ride the coat tails of the Integra gsr/Type R/NSX/Type S/ etc and label the VFR800 as VTEC and not VTEC-E, even though it is clearly an implementation of economy VTEC.

Here is a quick description found on google of what VTEC-E really is:

"VTEC E was a special form of VTEC used in the VX, and HX civics from the early 90s to the early 2000s. Most VTEC systems engage a pin at higher RPMs that lock in a new set of lifters that follow a more aggressive cam lobe; the result is better efficiency at higher RPMs.

VTEC E works on a different principle, instead of engaging a more aggressive set of cams at a 5000+ RPM, the system engages around 3000 RPM, and instead of engaging different lifters, it engages the rest of its valve train. Did you miss that? I'll explain a little more in depth.

Before VTEC only 12 valves out of 16 work. 4 intake, and 8 exhaust valves (as you can see in the video). Why do this? One can argue that Honda has some slick engineers but I know that Toyota found something out in the early 80s by total mistake that likely lead to Honda improving on the method. By speeding up the intake charge at lower RPMs you get a different flow into the head, this is commonly referred to as a "swirl effect." Toyota, as the story goes, found this out by accident when experimenting with different intake methods. The system they designed in response, know as Throttle Varied Intake System or T-VIS, blocked off 4 of the 8 intake ports into the head of the 4AGE below 4200 RPM. the effect was similar to the VTEC E system in the civic HX and sped up the intake charge causing a "swirl effect" although it was not as effective as VTEC E.

The result of TVIS was improved mixture of the fuel which lead to more low end torque, and once the engine got up to speed the TVIS system would open up to allow all 8 ports to feed the head.
Improved mixture of fuel not only means in increase in torque, it also means that it is more stable when being combusted, which means that there is less of a chance of predetonation and damage to the engine.
VTEC E accomplishes the same thing, however its directly IN the head and causes a more dramatic increase response and torque. On top of that it has a set of fuel maps that take advantage of the heads ability to mix the fuel and can lean out as far as 25:1 AFR. On a warm sunny day with an unmodified engine a driver can get as high as 51 mpg going 65 on the highway.The engine can accomplish higher AFRs by use of a wideband O2 sensor, another interesting facet of the HX.

Once you get up to 3000 rpm the intake air is getting too resistant to allow proper fuel and air intake through one valve, there is also so much load and fuel being used that the risk of detonation is too great. so the VTEC system kicks in (yo) and engages the other 4 valves in the head and it drops into a stoich mixture of fuel.

The stock cam journals on the D16Y5 motors (the HX) is similar to the Y8's. However the Y8 reigns superior in performance, some old D15 blocks from the VX used a two stage VTEC system that engaged an even hotter cam at a very high RPM. The system was complicated and very fun to explore.

The question is, is it an eco car? or a hot rod waiting to happen (here me out on this)? and the answer is both. The HX truly is a car that depends on driver input. running in power above 3000 rpm is going to suck your gas away, but you'll have much more pulling power in 5th gear than an LX civic. driving as the ECU asks (via the shift light) will gain you some serious change in your pocket. The HX is designed to be a highway machine, in top gear it is able to overtake traffic starting from a matched velocity rather quickly and without down shifting, in no small part due to the cams being more aggressive.

To add to that, the Y5 head has roller rockers to free up the drive train. and with that, anyone who knows about tuning these little engines knows where im going with this.

To sign off on this, in no way shape or form am I talking about race performance. The HX will get whipped by almost any other civic besides an LX. It just happens to have some oomph on the highway, some good starting power, and hilariously good mileage while doing it."

To further elaborate on the differences of the fifth gen vs the sixth gen VFR800:

It makes total sense on why even though the Honda marketing team touted an increase in performance (a blatant lie) with the VTEC (actually VTEC-E) valvetrain, it actually reduced performance (running extremely lean AFR mixtures will improve economy, but reduce power). This also makes complete sense as to why the VFR VTEC responds so well to fuel enrichment and ignition timing advance, while in 8 valve mode, as the swirl being created in the combustion chamber greatly improves combustion stabilization and allows for the ignition timing to be advanced much further with out detonation occurring, than the fifth gen engines could ever dream of.

It is really funny that the sixth gen VFR800 VTEC, is actually the perfect platform for "Hyper Miling" or as it is often referred to as "Eco Modding", but no one seams to have connected the dots yet.

One could, in theory, run a catless header (air fuel ratios well over 15:1 will destroy a catalytic converter), a complex tuning system, pick the fuel and ignition cells that correspond with light throttle/steady state highway cruising (say 2-3% throttle and 4000-5000 RPMs) and lean just those 6 cells out to and AFR of around 20:1 and advance the ignition timing, then get an obscene amount of MPG. (Eco Modders are getting well over 60 MPG out of the 1992-1995 Civic VX with the lean burn d15z1 engine and tall gearing, out of a car that is much larger and heavier than a motorcycle, with twice the engine displacement and no where near the aerodynamics)

This is a good read for anyone wanting to learn about eco modding. It is a mind blowing read, as all the principles that you have learned for making maximum power (cold air, 13:1 AFR, conservative timing high compression etc), get blown out the water when you are talking about maximum efficiency. For maximum efficiency, you are talking about 21:1 AFR, a ridiculous amount of ignition advance (super lean air fuel ratios take much longer to burn, so they need to be lit much earlier), low compression ratio and extremely high intake temps (to vaporize the fuel for easier combustion).

http://www.d-series.org/forums/forced-induction/117099-i-did-some-fe-testing-64-8mpg.html

Baileyrock

Honda tried to spin it otherwise, but by introducing the Vtec on the 6th gen VFR, the 2002 VFR already meet the tighter emission standards coming in 2006.

This is a very interesting point and we're actually seeing this same thing happening in response to the new Euro 4 regulations. Quite a lot of time, money and energy is being put into engineering bikes to meet the stricter noise and emissions regulations. I remember reading an article about the extensive engine noise dampening required for the new Ducati Panigale. The engine itself was far too loud, much less the exhaust.

As you said, Euro 3 regulations came into effect in 2006 and came with tighter emissions and noise requirements. The 6th gen is whisper quiet in operation compared to the 5th. I'm sure it's also cleaner burning.