hi guys
i have civic 92 i swaped d15b vtec
the orignal solenoid open the vtec at 5000 rpm from a signal in the ecu.
the b30 ecu from the sir b16a open vtec at 4000 rpm.
my friend told me that he can do something in the ecu (instal software belongs to ecu b30 SIR in my ecu)
so if i made it open at 4000 rpm it'll be cool i think. so what do u think guys?

 

get a vafc and u can set the vtec at 2000 if u want

 

VTEC is not like a turbo where there is something to be gained from making it spool sooner. VTEC is a second set of cam lobes optimised for high RPM performance, engaging it at a lower RPM will only decrease performance.

Now, it is true that on DOHC VTEC engines there is a little power to be gained by engaging it a <U>little</U> sooner. Apparently Honda engineers wanted us to feel the VTEC "kick" so they programmed it a little late. Still, it's only by a couple hundred RPMs and you need a dyno to know exactly how much sooner to set it, you can't just take a guess.

And finally, the P30 ECU engages VTEC in the neighborhood of 5800rpm (don't know the exact spec, going by what my tach indicates).