Im abondoning my v8 rx7 project and I have been offered an s4 t2 with some burnt wiring, and an s5 t2 that got rolled but has a strong running engine, harness, transmission. Ive read most of the posts about the s4-5 swap are just the motor, but what about the entire harness and motor? does the s5 ecu and harnesses mate with the s4 guages, dash, etc? or would i be looking at a guage cluster and dash swap assuming those are still in good condition? Or would it just be easier to rewire the burnt wires and mate the s4 probes etc to the new motor?

or should i just sell it for around $2.5k and save up for a nice s5 t2?

any and all feedback much appreciated. (searching makes it very difficult to find information on this as 's4' and 's5' are too short letter wise for the search function.)

 

Your best off sticking with the electronics of that series.

S5 harness won't mate to S4 harness without hacking the wires/splicing.

If you have a whoel donor car you can pul it off no prob though.

I am dropping a S5 TII in my S4 NA.
I needed the front cover swapped to S4 with mech OMP.
S4 Throttle body and TPS(single not dual).
S4 injectors
S4 harness
S4 ECU
I think S4 EGR(square plug not oval)

This is going to be the most plug and play method for me because I don't have to pull the dash apart.

 

ok so aparrently the story with the S4 wiring harness is that whoever installed the engine used wrong injectors (probably used him imp instead of low imp) and that fried the secondary injector wire all the way to the ecu (inluding ECU) so should i try to use s5 ecu and wire harness or buy new ecu?

 

hope this helps...

http://www.rotaryresurrection.com/series4swap.html

 

thanks for the info, after some negotiations and reasoning i think im gonna trade him my rx7 for his s4 t2 straight up, buy an ecu and run the secondary injector wire, assuming the rest of the car is striaght as he says.

Question: How fried can the ECU be if it still runs fine below 3800 rpm??

 

ttt