Originally Posted by imnot4n
From my understanding, for the VTEC to kick in then you need to hook up a shiftlight (or tach) to the vtec cylunoid or something like that for it to work right. The shiflt light that I have has ajustable rpm to be set so that the shiftlight comes on and the vtec kicks in, so ive been told.
VTEC is controlled by the ECU unless you have some sort of piggyback (VAFC) in there to change where the VTEC would activate.
Some people hook up a LED or light to go on when the VTEC is activated...this is a VTEC light.
A shift light is part of some stock vehicles but it tells you when to shift for maximum fuel economy. In your case, and when you buy an aftermarket tach with shift light, you want it to tell you when to shift (so you dont have to look at the TACH, and can see the light out of the corner of your eye) for optimal performance (just before or at redline).
Again, two very different things...one has nothing to do with the other except they both light up to tell you something.