R.P.M.

Ok, so we all know that S4 and S5 rotor housings have different spark plug placement. (I only found out how to tell the difference recently LOL)



Anyways....using S5 housings in an S4 motor while using the stock S4 ECU shouldn't really be done, correct? Because of the diffence in timing.



I pulled apart my motor that I blew up in my S4 FC T2 and found that it actually had S5 rotor housings in it. The whole time I've had the car, its been running on a stock S4 ECU. So wouldn't the difference in timing affected the way it ran? Maybe it actually made it run better....because for at least a couple months I pulled the wastegate line off and it ran whatever boost the turbo could build. The whole time on stock electronics with a FCD, running 15-18psi on stock injectors, fuel pump....everything stock.



Just wondering what others thought of this. Would it be ok to rebuild the motor with S5 housings and still use the stock S4 ECU, but this time leave the wastegate line hooked up LOL.

Liquid Anarchy

...I was under the impression that the Trailing plugs don't really do that terribly much...



...I also remember some company selling machined spark-plug shaped BOLTS as a means to run pump gas with high boost, without detonation...

j9fd3s

people put s5 engines into s4 cars all the time, and while its probably not ideal it doesnt seem to be bad either.....