i just bought a crx hf with a d15b in it so the motor runs fine on the crx si ecu but my question is how do i wire up vtec? i would like to use a rpm switch but i dont even know how to or what to look for
MSD makes a RPM activated switch and has all the instructions to wire it up, but I would suggest converting to OBD 1 and getting the P08 ECU instead. VTEC works off oil pressure. A RPM switch will not read that, so if for some reason you run low on oil or pressure, you have the chance of seizing your engine, where as, the ecu will not let you go into VTEC if it detects low oil/pressure.
If you want a great upgarde for the IM, go find a used Y8 (96-00) ex civic manifold and swap over the sensors and use that. Its the type r manifold of the d series. the only sensor that might not work is the IACV on the back, due to the casting differences, but shouldn't be hard to find. also a bseries throttle body to boot, like a LS or GSR!
i think i over revved the car and did some damage cuz it over heats at high rpms now and it feels like it doesnt make as much power and i have to basically floor it to keep it from stumbling at low rpms HELPPPPPPPPPP