what pins on the main harness would i have to swap to run a s5 ecu on a s4 harness?(splicing a s5 plug to s4 main harness)

 

what exactly are u trying to accomplish? why do u wana do that^

 

All of them. They're completely different.

Why?

 

im trying to run a s5 in my s4 ive got the s5 eng harness what goes to the ecu from
the main harness?

 

get a megasquirt and save yourself the headache.there are very few detailed diagrams for S4's (my personal experience).better off running S5 keg and S4 harness ,ecu,injectors,etc.

 

Not only are the pins themself completely different on the s4/s5 harness. The ECUs do different things in different ways You really should keep the harness and ecu together as a combo.

You can get N/A harness for a decent price in the for sale section. and the S5 N/A harness WILL run a turbo with just three wire changes.

OR get a stand alone.

 

LUCIU$ is the answer: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s4-na-s5-jdm-turbo-conversion-405617/page2/

 

http://www.rotaryresurrection.com/2n..._s5_diffs.html

Just say NO to cross series swaps.