Connect V2 ECU to V3 loom
 

I'm planning on buying a 1997 WRX rally car in the next week, the rally car has the stock ECU. However tuning options for this year of WRX involve buying a complete aftermarket ECU instead of mapping the stock unit. I have however been tuning my 1995 WRX for quite a while using the add-on chip socket (27C1028 chip) and I'm quite comfortable with it.

I'm therefore considering soldering the 3-plug ECU loom from the 1997 car onto the 4-plug V1/V2 plugs so that I can connect a V1/V2 ECU which I can then map by using the chip socket. I understand that I will have to change MAF and injector scaling at the minimum to get it working fine.

On the electrical side, the pinouts for the V2 and V3 ECUs are almost identical. The one thing I will have to change is connecting the ignitor outputs in pairs from the V2 ECU to the loom (#1#2 and #3#4 together).

Has anyone done something similar or can anyone point out anything I've missed in my estimate of what's required to get it working on the ELECTRICAL side?

Thanks.

No I think you have most of it covered.

You may want to consider getting a 4 plug ecu car loom and swapping it into the car and altering the bitd in that as required.

The coilpack wiring should just be a case of rewiring it.

Ignoring the cost for a moment you may consider though that if you got an after market ecu installed you should pick up mapping it for future changes quickly and have a far better end result.

Simon

Thanks JGM,

I will consider swapping the entire ECU loom as well, I think it will mean less tinkering around with wires.

Only other thing different is throttle position sensor, it works in reverse so you would need to swap + and -

Simon

Thanks, I'm sure that would have given me no end of headaches to troubleshoot.