Disable the VTEC Solenoid Valve

[Guest xracr]

Does anyone have any experience energizing the VTEC solenoid valve so that the engine is in full time 4 valve mode ?

[Guest]

So this question was asked last year, but no one answered. Seemed like a great question:

http://www.vfrdiscussion.com/forum/index.php/topic/57335-disable-the-vtec-solenoid-valve/page__p__678750__hl__%2Bdisable+%2Bvtec__fromsearch__1#entry678750

Looks like you can apply 12V to the solenoid, and it will enable 4 valves all the time.

1) Will this confuse the computer? I don't think so, it seems like its a one way street on this circuit.

2) Will it run like crap below 6800 RPM? No other 4 vavle bike seems to have an issue. Doesn't run that great anyway WITH the VTEC!

3) Will a PCIII or PC5 compensate for the extra valves? Does it need to?

4) AND... has anyone tried this???

Derek

[Rice]

There was a discussion (can't use search function myself, but you can google it).

The outcome was that the low speed responce will be crap - It is better with two valves.

And unlike other 4-valve bikes, this engine/intake/fueling, etc... has been designed for 2 valves low and 4 high.

Also, since you have an 06 (right?) your VTEC should not be an issue at all.

Why would you want to disable it?

[Guest]

There was a discussion (can't use search function myself, but you can google it).

The outcome was that the low speed responce will be crap - It is better with two valves.

And unlike other 4-valve bikes, this engine/intake/fueling, etc... has been designed for 2 valves low and 4 high.

Also, since you have an 06 (right?) your VTEC should not be an issue at all.

Why would you want to disable it?

Well, the bike is stock. And I can feel a pronounced jerk when it kicks in, usually in a turn. I decided to enter turns over 7000 RPM at the moment to avoid it. Why do you say that 06+ is not an issue?

Thanks!

Derek

[Polarbear]

Would be easier to buy a Gen 5 ... Just saying. But from a more theoretical point of view, interesting question.

C

[Rice]

02 through 05 the VTEC engagement was at about 6800 RPM and it was quite pronounced on some bikes (not on all).

Beginning in 06, Honda lowered the engagement point to around 6200 (IIRC) and smoothed out the engagement through fueling changes.

I've owned (still do actually) an 02 and an 06.

On 02 the VTEC was a biatch (for me sometimes). Why sometimes? Well, b/c sometimes it'd be perfectly smooth and sometimes it would chirp the rear wheel.

After several years of trying to find the cause of the difference, my non-scientific method has lead me to humidity. As soon as humidity raises, the VTEC starts kicking like a donkey. Don't ask me why - This is just a personal observation.

My 06, while MUCH smoother than 02, still lets VTEC come through a bit more in high humidity. None of it bothers me, because I have something to compare to. It is nowhere near as pronounced as it was on 02.

You've just started to ride this bike yesterday, I presume. It is the humidest (if there is such a word) time of the year. Wait until the humidity goes down and you'll be surprised at how smooth it becomes.

If you start disabling stuff, you will create more problems than you were trying to solve IMHO.

My advise is to save time and money and give the new bike some time to grow on you.

[johnmark101]

With a Power Commander you can adjust the fueling to smooth out the engagement point. I have an 03 and am using a map downloaded from this website. Works very well.

[Guest]

02 through 05 the VTEC engagement was at about 6800 RPM and it was quite pronounced on some bikes (not on all).

Beginning in 06, Honda lowered the engagement point to around 6200 (IIRC) and smoothed out the engagement through fueling changes.

I've owned (still do actually) an 02 and an 06.

On 02 the VTEC was a biatch (for me sometimes). Why sometimes? Well, b/c sometimes it'd be perfectly smooth and sometimes it would chirp the rear wheel.

After several years of trying to find the cause of the difference, my non-scientific method has lead me to humidity. As soon as humidity raises, the VTEC starts kicking like a donkey. Don't ask me why - This is just a personal observation.

My 06, while MUCH smoother than 02, still lets VTEC come through a bit more in high humidity. None of it bothers me, because I have something to compare to. It is nowhere near as pronounced as it was on 02.

You've just started to ride this bike yesterday, I presume. It is the humidest (if there is such a word) time of the year. Wait until the humidity goes down and you'll be surprised at how smooth it becomes.

If you start disabling stuff, you will create more problems than you were trying to solve IMHO.

My advise is to save time and money and give the new bike some time to grow on you.

Ah, you mentioned chirping, and that is exactly what happened. I was in a turn and the rear wheel chirped when VTEC kicked in. I wondered how can this be good? And yes, it is about 2345% humidiity right now. I didn't even want to ride it, but I figured I should since I just bought it!

So maybe the fueling could be toned down a bit at that engagement point. I was thinking about getting rid of VTEC to see how it rode. Seems simple enough, but I am sure someone must have tried this already, and I'd hate to find out after the fact that doing this mode destroys something, after its too late...

Agreed - I've had it a few hours and may be pulling triggers too early, but its in my blood... can't help it!

Derek

[Guest]

With a Power Commander you can adjust the fueling to smooth out the engagement point. I have an 03 and am using a map downloaded from this website. Works very well.

Yes, I figured this might be the case. But I haven't read this to be a 'magic bullet'.

What I don't understand is, there are countless bikes out there using 4 valves all the time and run fine. I agree that the extra swirl produced by only two valves probably helps a little bit in the low end, but the trade off is not worth it. That is - assuming disabling VTEC doesn't make the bike somehow run horribly due to the ECU.

Derek

[Veefer800Canuck]

Get some jumper wires, do it and report back.

[Infidel]

Its a Love Hate thing really. Some like it some don't. I love my VTEC transition personally... but like the guy said above. You'd probably come out better to sell your 6th and get a 5th. Might even make a buck or two depending on the deal. Less headache also.

[Guest]

Its a Love Hate thing really. Some like it some don't. I love my VTEC transition personally... but like the guy said above. You'd probably come out better to sell your 6th and get a 5th. Might even make a buck or two depending on the deal. Less headache also.

First of all - 5th gen is better in what way in regards to VTEC? I guess it doesn't have VTEC? Second, no way! I love my RWB 07!

I could deal with weaker low end, assuming it is decent. I don't think it has any low end the way it is now anyway. Feels like a 600 without the top end.

[Guest]

Get some jumper wires, do it and report back.

Thinking about it. Hoping someone did this already... but I may try it. Looking at wiring diagram for best switched 12V power.

Maybe I can put on a toggle switch, one setting for normal operation, and one for 4-valve all the time.

[Infidel]

Its a Love Hate thing really. Some like it some don't. I love my VTEC transition personally... but like the guy said above. You'd probably come out better to sell your 6th and get a 5th. Might even make a buck or two depending on the deal. Less headache also.

First of all - 5th gen is better in what way in regards to VTEC? I guess it doesn't have VTEC? Second, no way! I love my RWB 07!

I could deal with weaker low end, assuming it is decent. I don't think it has any low end the way it is now anyway. Feels like a 600 without the top end.

You will find a variety of opinions on why the 5th Gen is either better or worse than a 6th gen. I don't know enough about the 5th Gen to make a comparison personally. I do know that the 5th Gen does not have a VTEC Transition and that was the reference to the comment. I guess it just all depends on you. Do you really disllike the transition? If you do, you might not ever like it and grow annoyed with the bike. I am in no way to make that judgment for you. Only you can do that. If it isn't that bad then I'd leave it alone and try a PCIII or PCV with a new MAP for the transition. My 07 RWB is smooth as silk. But, I have the Turbo City FPR with a PCIII and using Cozys MAP from the File Section. Plus some other doodads here and there. My VTEC is smooooooooth.

[hondalover]

Depending on the miles your bike has on it might be a factor as well. I bought my '05 with around 2,200 on the clock and it now has nearly 40K. At around the 10k mile mark the transition got much smoother. Your bike being an '07 should transition from normal operation to VTEC at 6,400 rpm, where is the '02-05 bikes make the move at 6,800. IIRC you are coming off a sportbike, and the VFR is NOT a sportbike, especially when it comes to power-to-weight ratios. So my suggestions are: get used to it and enjoy it for the bike it is, buy a PC and do your own R&D, or sell the bike and buy something that is perfect straight out of the box (good luck with that one).

[dpcincy]

Wasn't there a post about this not too long ago that included a dyno run with the change in place or am I losing my mind?

[ggathagan]

It's not a matter of whether or not your engine could run great with all 4 valves engaged at all times; it could.

However, everything in the engine's design revolves around VTEC.

The FI mapping, the valve sizes, the head port design, the airbox design and all of the sensors used gauge what's happening in the engine would be designed around running on two valves at lower RPM's.

I don't know all the details of the 6th gen engine, but it wouldn't surprise me, for instance, if the two valves that are engaged at lower RPM's are a different size the the other two.

Point being that getting the most out of full-time 4 valve engagement could be quite a bit more involved than fooling the engine to engage all 4 valves and using a different map on a Power Commander.

I'm definitely not trying to discourage you; just pointing out some possible issues.

[Veefer800Canuck]

Wasn't there a post about this not too long ago that included a dyno run with the change in place or am I losing my mind?

I have not seen one, would someone please hurry up and do this? It's been 9 years already........

[vfr_steve]

Some great points and advice here and I too loved my VTEC bike, in fact, I liked all 3 of 'em and I still think it's one of the best looking bikes out there BUT... I hated the VTEC transition, as others have said, sometimes it worked flawless, smooth and seamless - but more often than not, particularly when the weather was cold and rainy, she would jerk and hit like a b**** and it annoyed the crap out of me - Since getting my 5th gen I can honestly say hand on heart I have never enjoyed motorcycling so much. There is no doubt the pre-vtec has a wonderful, BETTER engine, many pro's say, the best engine ever made... plus I haven't even got to the gear driven cams bit yet

It’s true the VTEC is the better handler – and although I do RIDE my bike, I never push too hard on the street and the 5th gen is lighter, has better electrics (2000/2001) blh blah…. Anyway sorry for the rambling. But that's my experience of VTEC vs the 5th gen. I did try to disable the VTEC system but it’s just not worth the hassle, do yourself a favour and buy yourself a 5th gen

Disclaimer – ALL VFR’s are the best sports-touring, all weather bikes on the planet, I should know I use mine like a car and I live in the UK

[spud786]

The only vtech hit i ever get at all, is in first gear , Everything else is jet smooth transition when it goes into vtech. Back in the first few thousand mile when the bike was new, the hit was alittle harsh at times, in first gear. It actually hurt my hands a few times and one time I was in 29 degree weather and had been riding an hour, and stopp to turn onto magor freeway, and gunned it in first gear and it hit so hard I thought the motor fell out That all faded after 3 ,000 mile or so, but over time it should smooth. But only in first gear I get a weird hit at times , not always, but somtimes.

I cant go along with the Humidity, riding year round in all type of conditions, I just dont see any difference. The key thing , the bike needs to be 170 degree and above or your fueling may not work right and cause weird hits. I know in sub freesing weather its possible to see the 160 range. But if you in the 140 or low 150's your lobale to get real crazy fueling issues.

Also IMO the reason the vtech smooths over time is because the vtchs valves tighten, reducing lag time , id be hesitant to adjust them Unless they were really bad and about to no longer close. Im pushing 90,000 mile with no valve check, course I run a Race leaded diet.

But no , it would be foolish , and expensive disaster imo to try and disable or lock vtech into constant mode.

02 through 05 model go in and drop out of vetch at 6800rpm 06+ go in at 6400 rpm, but do not drop out till 6100 rpm. this aides with not going in and out and gets you into vtech ealier. But riding around at 7,000 rpm to avoid vtech is mostly nuts. sell the bike if its that kind of issue.

How many miles is on your bike?

[kaldek]

I wonder, why don't people with VTEC issues start by trying different oil? I mean, it's an oil-activated system so why not try a different brand and weight of oil? If running full synthetic, try some semi-syn. If using 10w30, maybe try some 10w40 (or vice versa).

And always test your results when the engine is fully up to temperature.

[vtecal]

I love my VTEC.

[dogman]

I dont think its a good idea to engage the vtec spooling valve at lower rpms for all the reasons stated above, and also it is an oil pressure driven system, and it could be possible that the oil pump may not deliver enough flow or pressure at lower RPMs to hold the vtec actuating pins in reliably.

I would think a better option would be to replace the vtec lifters with standard buckets and shims,( if this is possible), or maybe just trade it for a fireblade or similar if it really bugs you.

[NorthernVFRDave]

I wonder, why don't people with VTEC issues start by trying different oil? I mean, it's an oil-activated system so why not try a different brand and weight of oil? If running full synthetic, try some semi-syn. If using 10w30, maybe try some 10w40 (or vice versa).

And always test your results when the engine is fully up to temperature.

You know thats a suggestion I haven't heard before. But sounds like a good thing to try.

I love my V-Tec too, and sound it makes

[Guest]

I love my V-Tec too, and sound it makes

You mean you love the sound of the V-Four! Unless you like the sound of the VTEC making your rear tire chirp...

The V4 sounds awesome, reminds me of the V4 Honda RC212V MotoGP bike.

Derek

[Guest]

I dont think its a good idea to engage the vtec spooling valve at lower rpms for all the reasons stated above, and also it is an oil pressure driven system, and it could be possible that the oil pump may not deliver enough flow or pressure at lower RPMs to hold the vtec actuating pins in reliably.

I would think a better option would be to replace the vtec lifters with standard buckets and shims,( if this is possible), or maybe just trade it for a fireblade or similar if it really bugs you.

Yeah, as I was driving home today, I also thought about the oil pressure not being enough to fully engage those pins at low RPM. I am not quite sure what would happen mechanically. There is no way to tell till someone (not me...) tries it. The other issue is that there will be MORE air flowing into the cylinders, but not more fuel. The fuel map would need to be changed significantly or else you may run too hot and burn up the valves. All the stuff 'ggathagan' said are also true, although most of the cylinder design would just make it run poorly. The low oil pressure and lean condition may damage something.

So in hind site... I think someone who has a vested interest in doing this and has a sacrificial bike would be needed. All in the name of science! But I am now too afraid to try it due to improper fueling.

Derek