jyeung528

so whats the verdict?

yes to vafc,

no to lowering vtec?

hyperpm

up to you

Johnny Sack

i decided not to fool with. i looks like you open a whole new can of worms on this if you fiddle with the vtec point, and a/f ratio. like he said its up to you...

jyeung528

i thought a/f was a good thing, like adds 10 hp.

i thought vtec point changing was bad, but is a/f tuning bad? how can you open up a can of worms with a/f tuning?

Silver9k

Well...the reason lowering your VTEC engagement point can be bad with a VAFC is that when VTEC engages the engine makes a lot more noise and vibrations then it was before.

The knock sensor will notice this and think it is knock. Then it will pull timing, hence the running like crap part. To really take advantage of lowering VTEC you need an EMS or other standalone. This way you can change the knock sensors parameters and lower its sensitivity at the engagement point.

Personally I plan on lowering my point to around 4500...right around where the high cams start to make more power then the low cams, and where you don't even feel it kick in. But then, I have an EMS.

jyeung528

I understand that lowering VTEC will "open a can of worms" BUT...

what is the issue with using a VAFC for air-fuel tuning?

Silver9k

it works...as good as any other VAFC, and you'll get some gains with it of course.

twohoos

It all depends on the tuning. I've had a pretty good experience with the VAFC -- decent gains, and no impact at all to driveability:

https://www.s2ki.com/forums/index.php?showtopic=188492