i just bought an s5 3b thats had a street port done and all the emissions/egr is blocked off on the motor and the oil metering pump has been removed. im trying to figure out what im going to have to do when i get the motor in the car as far as wiring(ive got s4 and s5 wiring harnesses) and vacuum lines since all this stuff has been eliminated. my car currently has a stock running s4 motor in it know that i can use for parts if need be. and is it possible to do any kind of wire tuck to these cars to clean up the engine bay?

 

If you intend to use any electronics from the S5, you'll probably get in over your head. The wiring/sensors/ECUs between series are very different.

This is a similar thread: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s4-n-s5-turbo-swap-916499/
The easier route: http://www.rotaryresurrection.com/2n...o_s4_swap.html