i have an turbo motor
 

how can i tell what year is my engine......and what ecu and harness do i need?

Engine
 

If you have a aluminum thermostat housing and mechanical oil metering pump
(metal rod that runs from throttle body to lower front right of motor),
then it is an s4(87-88)
If you have a plastic thermostat neck and electric oil metering pump (2 white electrical connectors above waterpump housing),
then it is a s5(89-91)

As far as which one you need, it depends on what year your car is?

Either one can be used, but you will need your corresponding years
turbo harness, ecu, afm, boost etc.

you could sell that motor, grab 13b re cosmo motor and a microtech and call it a day

And I could sell my house and buy a ferrari and call it a day too, but that would leave me homeless now wouldn't it! Do what CJ says and you'll find your answer!

cosmo engine =1200......dman i should of got a ferrari:wallbash:

lol.