I got a turbo series 4, how hard is it to swap a series 5 ECU and wiring harness and hook it up in a series 4

has any one done this before? and dose anyone know any links / posts to do this swap

thanks

 

i hear you have to rewire the dash

 

And I can't think of why you would want to do it unless you want to swap the whole engine or something. Probably not worth it. Of course, I am still not sure of all the differences between S4 and S5.

 

The S5 is supposed to have slightly lighter rotors, and higher compression. This lets it run slightly higher boost, and also lets it have a redline slightly higher than than the S4. Would swapping out the ECU from an S5 to an S4 work? I can't answer that question, but I wanted to point out the differences between the S4 and S5. Based on what I know I don't see how the ECU would be able to work right.

 

Yea I got a complete series 5 motor here with ecu
can it be done? or if anyone has done it b4

 

Swapping a S5 ECU into a S4 is a serious rewiring job for very little (if any) gain. Easiest is simply to keep the S4 ECU and loom, and apapt the S5 motor to suit. You'll need to swap the front engine covers because the S5 electronic OMP won't work with the S4 ECU. You'll need to swap the injectors because they're different impedances. You'll need to plug the tee in the wastegate actuator pipe because the S5 boost control solenoid won't work with the S4 ECU (or install your own boost controller). You should swap the thermostat cover so you keep the filler cap on the neck. There's bound to be more...

 

yeah i know i could do that easy, but i really want to run it on the series 5 ecu , its faster, little better AFM, better timing and better fuel mixture, all i want to know can it be done and if any one has done this before, i got both series 4 / 5 Factory Service Manuals so that will help a little

 

While the S5 ECU is faster, most of its extra performance went into emissions control and self-diagnosis. I highly doubt you'd notice any difference in performance. Remember most of the S5's extra 13kW came from higher boost. And what do you mean by "better" timing and mixtures?
If you have the complete wiring diagrams for both cars (not just the FSM), then I'm sure it's possible, but it'll still be a very complex job. The S4 loom will be missing a few of the inputs the S5 ECU requires too, so some things (like idle control) may not work properly.

 

Also a difference of 15% lighter Flywheel. A whole 3 pounds.

 

Yes it's lighter, but flywheels have zero effect on power.

 

How about "unleashed" or "hidden" power?

 

I had an 88 with a series 5 motor and did not rewire any thing and had 280-300 hp to the wheels. There are two important things though. Series 5 motors have high resistance fuel injectors unlike the series 4. You will have to swap out injectors and injector harnesses.

Also the oil metering pump is electric. But don't worry. You don't need it. Just use 2 cycle oil in the gas and you will be better off than before. 2 cycle oil is made to burn easier and cleaner than conventional oil. So what does that mean? A happier rotary.

I have had no problems at all. It was much faster and had more torque.

Also I had a turbo II. So if you have a N/A, then you have to rewire and swap the ecu.

 

no, if he wants to run the S5 ecu. he requires to have the s5 OMP hooked up. other wise the ecu will not run. there is no way around that.


don't even bother trying to change them... there is no point what so ever... it will take you weeks to get it running. if you ever do. and when you are done. there will be no difference.

if you really really want to rewire your car for a new ECU. save up for a haltech... I bet you could sell your S5 ecu and harness and be half way there $$ wise.

 

i have a shell of an 88 turbo that i will be putting an n374 ecu and a modified s5 NA wiring harness. But i will also be putting a S5 jspec engine in it soooo, no big wiring problems, just plug and play. i will use S4 sensors for the gauges, but it wont be too much work

i cant really see any point in going through all of that just to go to a s5 ecu, performance gains would be barely noticed. unless you get a S5 motor. its a waste of time IMO

Justin