I found an s4 gxl with an s5 turbo 2 drivetrain swap. The only things that are needed to finish it are wiring and a driveshaft. I ahve heard that it is harder to wire an s5 engine into an s4 care? are parts hard to find for the s5?

the s4 and s5 wiring are different.



so there are 3 ways to do it



easiest; run all s4 wiring



hardest is a tie between converting the whole car to s5 or making an s4 car to s5 engine adaptor harness

like i posted in your other thread ALL the info you need is in this link.

http://www.rotaryresurrection.com/2ndgen/techmenu.html

I believe the S5 has an Electric OMP and the S4 is mechnical, requiring a different ECM as well. If the price is right, you could always go the standalone method (Haltech).