I just got a 94 hatch cx model and planning to swap a d15b vtec, but somebody told me that you need a rpm window switcher or something like that, to run the vtec consitantly. is that true? or there another option on running the vtec.

 

d15b vtec? that's a new one on me. i run a d15b7, which is most deffinately not vtec...

 

You haven't been around long, have you?

D15B is basically the JDM equivelant to the D16Z6 with .1L less and a higher comression. It is an SOHC VTEC engine.

First off, why would you want to run VTEC constantly? Bad idea...

Get an SOHC VTEC engine wiring harness to make it easier on you and then run the VTEC wires to the ECU. Simply run a P28 ECU and you're good to go. It's a simple swap. There is a sensor that is not on the intake maifold of your CX that isn't on the D15B. You might need to make provisions for that so you don't throw a code, but that's the only hickup about the swap. hih

 

you know i haven't been on long... you've helped me a number of times. all i was saying was that i wasn't aware there was a vtec version of my engine.

 

okay^^ the problem is that I don't have sohc vtec harness. I just have the plain obd1 harness that came with the non vtec engine. I mean it should work right, but I probably have to do some wiring?

 

ya, that should work. You will need to run VTEC and VTEC oil pressure wires for sure.

 

BTW, what are the HP differences between d15b & d15b7?

 

Does your new motor come with its harness? I just cut the vtec plug off the JDM harness and soldered some wire long enough to go through the fire wall and into the ecu. All you would need is a ground, vtec purge selenoid wire and oil pressure switch wired in. It sounds complicated. I even hesitated to do it for like a week. But when I did it, it took about 15 minutes tops. That includes smashing some spare sensors to get the little wire clips out.

 

Oh, you will have to use a newer O2 sensor as well because the D15B uses a single wire O2, while your harness will have a four wire O2. FYI.

D15B is 125 chp: http://www.usedjapaneseengines.com/e...erformance.htm

 

what about the rpm switcher thingy, I don't know what they called but it's supposed to activate the vtec or else i'm just running on a plan non-vtec motor. I think they called it like rpm window switcher ? I don't know.