I'm having a engine put together with bits and pieces of s4 and s5 engines combined, S5 side and intermediate housings, s5 rotors, s4 rotor housings, and S4 intake manifolds. Now I'm wondering after its been all set to get put together... will the ECU be pissy with the motor due to the increase in compression ? And if so how can I correct that ?

Also anyone else see any foreseeable problems doing this combo ?

 

Nobody with any suggestions or help ?

 

You'll need the S5 flywheel and front counterwieght as well to keep the engine balanced (the S5 rotors are lighter than the S4's). The ECU will be fine.

Henrik
87TII

 

Good point on the counter weights!

The ECU will be just fine.

Chris

 

if you could just change the flywheel to a lighter one and with the lighter counterweight.. does it really matter what flywheel you have on there if the counterweight co-responds ?

 

Also Nobody has mentioned.. I probably would need more gas (ie. larger injectors)

 

No you dont need an s5 flywheel and c'weight only a matching flywheel and counterweight and no the s5 non turbo used the same amount of fuel as the s4 non turbo. -Gabe