Okay I'm having an engine built and here is the whole Scenario. Help on any part will be greatly appreciated.

This is how I start off. Full S4. Its engine is blown, time for rebuild. Wanting to get a increase in Hp, I want to go with S5 components. I go with S5 Front, intermediate, and end housings. I keep the S4 rotor housings cause they are in great shape, possibly replaced in an earlier rebuild. I also go with 9.7:1 compression rotors. I also go with a aggressive streetport.

Now here starts my questions.

Intake Manifold

Will the S4 manifold still bolt on to the S5/S4 mixture I have ?

Flywheel

Will the stock S4 flywheel work with the engine or do I have to goto a S5 flywheel ?

Fuel system

Will stock injectors still produce enough fuel to feed this engine? (I do have a S-Afc incase there is a need to increase duty cycle)

Oil System

Will the oil system on the S4 still work with the engine or is there a conflict with the way it bolts to the S5 components ?

ECU

I've kind of had this answered in another post but while I'm on it.. Is there any conflicts known ?

Unknown

Maybe the worst part of all.. anyone can give me some seriously good help ?

 

You can use the S4 manifold, it will work fine. If you're using S5 rotors, youll need a S5 N/A flywheel. Im pretty sure the S4 fuel system will be fine. About the oil sytem and ECU, I *think* that the S4 ones will be just fine, but would like someone else to back me up, because Im not 100% sure.

 

well in the s5's, most of the power gain was in the intake manifold anyway, so why not use that?

 

there was a couple of threads based upon what intake manifold was actually better.. seems that popular theories are.. s4 intakes are better for ported engines and s5's are better for stock engines unless they themselves are ported.

The real gain is in the higher compression rotors I thought..

 

Thats not really true. most of the power gain is from the lighter, highert compression rotors, and the extra 1000rpm redline. If hes streetporting, Id stick with the S4 manifold anyway, the shorter runners support a streetported engine better. He has pretty close to the same thing as I am having my engine built, and Im sticking with the S4 IM.

 

Yeah, its a pretty Large streetport that is going into the car, the last post did put another question into my mind... I wonder what my new redline would be.. because of my car being a 86' GXL its past redline was 7k... how do I determine what my new redline should be.. ?

 

I think you are also going to need the S5 front counter weight.

 

bump

 

What would be the best combination for an engine in a TII, running a single turbo with a large street port?

 

Yes you will need the S5 front counterweight. And about the redline, you will safely be able to rev to 8k with the s5 rotors, but should get it dyno-tuned to see where you stop making power, plus youll still be running the S4 ECU with the 7800rpm rev-limiter.