DOHC ZC - Mystery ECU and TurboEdit

M Rossi

#1 ◈ 2021-01-20

Hello PGMFI.ORG,

New to the Honda scene here. I've become more enlightened and have increased my knowledge exponentially browsing various Honda forums, builds and information sites.

Recently picked up a 1990 EF Civic Si with a JDM DOHC ZC Trans and Engine swapped for $2000. The motor has some amazing pull. According to the previous owner, it has a PG7 ECU with a "chip tune"; is how unspecific he described it. It has a 7200 RPM redline.

Since the aftermarket lightened crank pulley flew off on the highway, combined with the oil consumption on the engine, I'm planning on doing a basic motor rebuild and I'm slowly assembling a 14B turbo kit for it.

So...,

- Is there any way to find out what kind of chip I have in my ECU, and if Turbo Edit would be best for OBD0 turbo set ups?

- What sensors do I need to change/upgrade for OBD0 Turbo set ups? Will stock injectors be too lean?

- Lastly, do turbo manifolds for DOHC ZC exist or is custom fab job required?

Let me know what you think :D

Fernpatch

#2 ◈ 2021-01-20

Re: DOHC ZC - Mystery ECU and TurboEdit

Welcome to the forum. I am new here myself. Nice find on your new EF. I cannot comment on tuning the ecu as I am still learning about that aspect. When I had a 90 crx dx I swapped a dohc zc into it and built my own conversion harness to go from dpfi to mpfi. The best way to run the motor in stock trim is the jdm pm7 ecu. What I did and worked just fine is take the guts from a pg7 ecu and put it in a pm6 case.

From experience I wouldn't rev that engine over 7k rpm in stock form.

If you want to run more than 10 psi of boost you will need a new map sensor.

Your stock injectors and fuel pump are not up to the task of feeding a turbo engine. I would go with a walbro 255 and 550-750 cc injectors depending on your power goals.

For a turbo manifold you can use one for a single can d series. It will bolt right on but the ports will be slightly off. That is a easy fix on a cast manifold with a dremel or a die grinder. Just work the ports until they match.

Let me know if you have other questions. I have built, modded, and flogged a great many 4th gens over the years.

Good luck with your new project and enjoy the intro to the world of modded Honda's. It's a fun addiction.

Doh, I just realized that my lack of coffee made me miss the post date on this thread. Oh well, chide me if you must ;)