i just bought a 94 civic with a 97 gsr swap. the motor is stock but header and exhaust. it comes with the obd1 p28 ecu. when vtec kicks in it doesnt make a difference or at least i cant feel the difference so i was wondering would the p72 make alot more of a difference because vtec is pretty weak rite now. i have the obd2 p72 ecu but the cars harness is obd1. king motorsports said i cant just get a conversion harness they said i have to do a bunch of other **** too so idk what to do. is it worth finding a 0bd1 p72 or what

 

get your p28 chipped for a gsr.

 

check if the p28 is chipped or virgin to begin with

 

its virgin

 

Think it's a gsr thing. I have a gsr swap with the p72, and vtec crossover is not as noticable as on a b16. It's more noticeable when the intake secondaries open up.

Which leads me to this - On a gsr, with a P72, vtec crossover is only at like 4600 rpm, which is much lower than a stock p28 crossover. Also, if you're using a P28 on a gsr head and intake manifold, your IABs are not working - they should open at like 5800 rpm. Which doesn't really matter because they default to open, but you'll get a little better low end with a p72 and IABs working.

Therefore, for best results, you should either get your p28 tuned for a gsr, or put the p72 in.

 

thanks for the help doods

 

A chip should solve your issue