Okay so i've been constantly reading Threads on here for the past few days and trying to decide what to do with my S4 N/A.

I've decided to use the N/A harness which i took my time to take car of it when i removed the engine.

Only question is. Is it possible to use the S5 turbo with an S4 N/A harness or even if i got a S5 turbo harness would it still be too much work?

 

i dont think so because either way you are going to be putting in a different wiring harness so it would be the same amount of work.

 

You have to use the S4 harness unless you want to rewire the rest of the car.

You have to change the front cover and use the S4 electrical components.

There is a writeup on rotary resurrection's site about it.

 

you could just wire up the s5 harness and ecu to match with the s4 chassis harness... i got another s5 chassis harness clip from the junkyard, and altered my s4 harness... just a thought