I have a chance to get a S5 Turbo motor and it is going to go into a S4 car. If I change the whole intake system to a S4 and premix would it be able to work? If not, what esle would I have to change. If someone could, could they list all that I would absolutely need to make the S5 motor work in a S4 car?

Thanks

 

Leave the slightly better S5 intake manifold on, there's no need to change it. If you want to retain the S4 OMP then you'll need to swap the front covers and throttle bodies.

 

So all the sensors and everything else work out fine? All I would have to do is change the throttle body and premixe?

 

What I want is to us as much stuff from the S5 motor, but use the S4 wiring, ecu, etc.
So I need to:
Change throttle body
Change injectors to plug into S4 wiring harness
Premix

Am I missing anything else?

 

If you don't want the OMP, you can leave the S5 TB in place. You only need the S4 TB for the lever that operates the OMP.

 

I think it would be better to use the s5 ecu instead of the s4's

 

Absolutely not. That would require a massive amount of extra work for practically zero gain.

 

So its just the injector plugs that I would have to change on the wiring harness? What would I have to do about the knock control unit because it's different with the s4 and s5?

 

Just plug the S5 knock sensor into the correct plug on the S4 harness.

 

Now your saying that I can get a S5 complete engine and everything will match up except for the injectors and the omp. And what about the tps? Doesn't S5 have two and S4 only have one?

 

There are minor differences but nothing major other than as per above.

You can wire up the narrow-range TPS and leave the full-range TPS disconnected.