[peaRl]

alright this has probably been asked a million times but i have not been on superhonda for a long time. i have an R and dont know too much about the VAFC. i know that you can set when you want VTEC to kick in and i know that you can control how lean or rich your fuel is running. is it bad for your engine to engage VTEC earlier than it should be. also how do you know what to set your fuel at and is it bad for your engine to run it more lean or rich? just concerned about my baby. thanx a lot for the info.

 

[zexed-hx]

you never wanna be too leanor too rich. you wanna be rich when your racin' around shootin' some shit (N20). As for the VTEC adjustment I'm not too sure. I know it should be dyno tuned to get it just right...but I know most people don't even bother for some reason

 

[PB FOOT]

get someone that KNOWS their shit to install it and tune it... tuning is key. bye bye engine is you lean it out. had a friend just tear up his h22 when he played with the vtec point and fuel maps. dynos are the best way to do it. the vafc is a great tool when used correctly.

 

[ITR#231]

On a relatively stock (or just ordinary bolt-ons) ITR, changing the VTEC x-over point lower will usually hurt performance. You can go 300-500 RPMs lower, but much more than that and you won't be moving enough air through the cylinders when the fuel maps change. With much more aggressive cams, you will greatly benefit from increaseing the RPM at x-over, since they move much more air in the non-VTEC lobes.

As for fuel tuning, only a dyno with a wide-banc O2 sensor will let you tune it properly. Again, if your car is mostly stock, you will benefit from leaning out the mixure accross the whole band, but you must always run 91 fuel or better after that. Honda has detuned most street cars to run on 87 fuel, which is why the timing is retarded a little, and the fuel runs a little rich. Rich mixtures also burn cooler.

 

[PreludeSiZero]

you can tune it with an A/F guage as well. it just won't be as fine-tuned as if you tuned it on a dyno.

 

[ITR#231]

you can tune it with an A/F guage as well. it just won't be as fine-tuned as if you tuned it on a dyno.

Personally, I would NEVER do that. The question is not "is my car as finely tuned as can be?" The question is "how much damage am I willing to do?" Those of you who have run an Autometer gauge know that they're next to worthless. You might be able to get away with the Greddy meter which has it's own O2 sensor, but it would cost you much more than dyno time.

Keep this in mine... ALL you can do with a VAFC is fine tune your fuel. Only a FPR, larger injectors, etc. will allow you to make large, sweeping changes to fuel delivery. If you can't fine tune with your fine tuning device, all you have left is a pretty display.