if i was to get a kouki engine (89-91) to put in my 87 turbo 2 what would i have to swap out?

i would get the jspec motor, saying that came with everything
engine, turbos, ic all that

don't i still need another harness, and ecu, because the s5 has a electronic wastegate?

is that all i would need, and would it be worth it?

 

major pain in the *** for a very little change. just get a 87-88 j-spec.

 

thanks for the heads up... id prolly just rebuld mine then if i blew it.

 

it's not a pain...i swapped mine and kept the '87 harness...the only thing you'll need to swap is the front housing cover since the s5 has the electronic omp and the s4 has the mechanical one....as far as the waste gate goes, you can do away with the electronic control if you're keeping your s4 harness & ecu, just get a boost controller. now depending on what year your s4 is, you may need to retain the injectors...
that's pretty much all that i did to the engine prior to dropping it in...i even kept all the vaccuming system, etc.
....
now the hard part would be if you want to do away with the old s4 electrical wiring...you'll have to get an s5 ecu, engine harness, front harness, and complete chassis harness...this is totally not worth it....

 

forgot one more thing...keep your s4 tb and tps...and just bolt that onto the s5 upper intake body...everything should bolt up just fine...