i'm looking at a dieing motor in my gsl-se. i'm considering the option of either having my engine rebuilt with the SE rotating assembly and S4 housings or buying a used S4 engine.

the question is could i use my SE injection gear (intake manifold, throttle body, injectors, etc) on an S4 motor assuming I use an SE front cover to mount it in my car all nice?

as long as the car is streetable like this, i would be happy. i'm not looking for major upgrade city here. it's just that S4 NA motors are easier to come by than GSL-SE motors.

and hell... down the line, i could throw down with the S4 injection system and a standalone computer.

what say you?

 

I've done this. The s4+ engines have larger ports, plus the parts are usually in better condition (rotor housings, at least) than the pre 86.

Yup. There is a port air passage at the LIM that the s4 doesnt have. This could affect emissions, if you need to pass a sniffer, other than that it won't matter.

IT wouldnt be terribly hard to engineer the stock s4 stuff to work without a standalone. The power gain would only be 10-20hp, and most of that can be gained by using the s4 throttlebody and manifolds in conjunction with your stock SE wiring/injection/sensors. I do this routinely and get 10-20hp (butt dyno) out of stock SE's. ONe day soon I will have a writeup on my webpage.

 

so the ports on the exterior of the motor should be the same size, save for that goofy little emissions hole? this is good news. also, do i need to block-off that air port thing?