IDB

car is a 97 prelude... right before vtec hits.... it bogs for a second... and the vtec comes in hard.... just wondering what it could be...

j4k3

It's VTEC lag.

Enigma

boots

what do you have it set it? meaning when does vtec engage?

IDB

its my friends car... its set at 5000

Enigma

Did you tune with a wideband? Or at least at the dyno?

boots

yea when you do a mod like that, that ties into the computer, you need to get it retuned because you're basically changing the ecu parameters

IDB

im just gonna initialize it so it runs on stock settings and he can pay to have it tuned....

SlowLS

Vtec engagement might also be set a little too low. Just set all the fuel settings back to 0 and turn the vtec engagement up some and see if it corrects the problem.

Enigma

No.


VTEC computers have two fuel maps, one for low cam profile and one for high cam profile. Messing with those VAFC's is a waste of time and money IMHO, because they can't control those fuel maps, they just "tweak" them.

SO, setting your VTEC to engage higher or lower in your RPM band WITHOUT tuning it WILL cause problems.

The reason: Engage VTEC sooner, you are still running on low cam profile fuel maps with VTEC engaged; engage later, you will be running on high cam profile fuel maps without VTEC.


Does that sound like fun to you?