Ok so heres the deal, I bought a beater FC with some extras.

Car is a compelte running S4 with an auto...

Ive also bought a complete drivetrain conversion with LSD from an S5 as well as s "stage 2" ported S5 engine.

I have both S4 and S5 ECU's and S4 and S5 wiring harnesses.

Now what im wondering, whats the easiest way to make use of all these parts best.

Will the S5 harness with ECU be able to drive the stock tach from an S4? or should I try to use the S4 external parts on the S5 keg and do it that way

trying to figure out whats easiest on the wiring.

any ideas?

 

stick with the S4 wiring and ECU... too much work to make a S5 engine harness and ECU work in a S4 body

 

so can i use the S5 block with the S4 accessories on it without too much hassle?

that and ... the S5 manual tranny will mate to a S4 Flywheel/Clutch/Engine right?

 

Nevermind read another post of yours... I guess I can just modify the S4 harness to accomidate the S5 engine.

My only question now... will the S4 AC compressor bolt onto the S5 block? The AC is fully charged and working and I'd hate to see it go to waste..

Thanks!