Ok guys I just bought another h22 accord and It was running a p72 and I didnt think that the p72 was chipped because I couldnt feel the vtec kick in or hear it at all.. if it was on a scale of 1 to 10 of how much you can feel it kick in I would give it a 2 , but I want to keep the p72 because of the knock sensor and stuff.. .. So I put in my old p28 with a h22 basemap today and and I could feel and hear the vtec kick so much more.. So today I was bored and happend to open the p72 and noticed it had a chip but the ecu was diffrent from the p28 it had like a small circuit board on the top right with 4 screws in it and it has like a data cable in it.. Like the ecus in the hondata s300 picture.. So what I was wondering is if I can put my chip from john vega in there cuz I dont wanna end up messing up something.. And since the p72 is chipped why cant I feel or hear the vtec

 

my guess is either the VTEC timing on the P72 is way off, or its disabled.

if VTEC engages either really low or really high, it wont have as pronounced of an effect.

the P72 (B18C ECU) may also be a little lean for the 2.2 going into VTEC, so less gas = less power = less "hearing/feeling" VTEC...

just a guess tho, im no ECU genius

 

yea that Makes sense thanks..

 

On a properly tuned vehicle, vtec should be engaging at the best transition point between both cam profiles. (The smoothest point).

A p72 ecu is scaled for 240cc injectors from the factory.
Prelude injector sizes
92-'96 Prelude VTEC Peak and Hold 345cc
97-02 Prelude vtec Saturated 290cc

As you can see a prelude uses larger injectors then 240cc.
Using a stock p72 ecu on a h22 is never a good idea in my opinion. Using a p72 ecu to have your car tuned on is a great idea as it is the only ecu that officially is supported by most tuning systems using intake air butterfly support.