SETTING VAFC

[red3]

hey guyz..i have a 93 JDM vtir lude with a VAFC..i just wanted to know at which rpm should i set my vtec engagment point for max power?..thanks guyz...=]

[ECU-MAN]

5500rpm no point doing it anywhere else as your high speed fuel and timming maps cut in @5500

[azjs]

Most tuned vafcs on preludes I've seen have had it set -slightly- lower - obviously accompanied with some a/f tuning too.

No point moving vtec and nothing else.

-az

[WPN.22R]

well mine cuts in at about 4600 (with boost). it was the best point found while on the dyno. but (no offence) i dont think having vtec cut in any earlier or later would really benefit. its set to come in at 5000 right. thats tops for everyday driving.........

then again unless you want to do a bit of hammering? up to you

[McChook]

Stick it on the dyno, and make the change over point 7000rpm. Run it up on the dyno and stop at 6500rpm. Then, set the change over at 4000 rpm, run it up on the dyno all the way to the rev limiter. Then, get you tuner to stick both graphs on one sheet of paper - simply match the graphs together, and one single best point will be found - Standard, you can smooth it out a little, and gain a few midrange hp, but not a lot - you will need the AFC tuned as well, the midrange is very rich, and leaning it out a little will find a bundle of power everywhere in the range. A few modifications can see the change over point ont he prelude very very flat, where almost no jerk will be found - unlike standard, where you really feel the change over.

[WPN.22R]

right on mcchook! thats how mine was done.

[edw-R]

Go to dyno. The tuner would adjust which point the V-tec on. Good luck!!

[DaViSoN]

i'm not fond of changing the vtec engagement form 5000... but i find the kick into vtec is too strong and sudden at 5000... so i tend to sometimes set it at 4600.. feels alot smoother for me. But thats only IMO