let me start out that i have searched but theres to many threads and i cant get a solid answer so if you can point me to thread that would be great to.

okay now i have a s5 engine im dropping in my car and i want to put the s4 5sp tranny on it, do i have to have an s5 flywheel? if so are the s4 and s5 trannys the same and a s5 flywheel will attatch to a s4 tranny, i have harness and ecu so am i missing anything else?

any help would be fantastic thanx.

 

The stock flywheels have a counterweight built in that is matched to the weight of the rotors. This is why you need an S5 flywheel on an S5 motor and an S4 flywheel on an S4 motor. S5 Rotors are a bit lighter then S4.

You will need the S4 mounting bracket to mount the transmission to the car because the S4 and S5 mounts are different on the transmission side.

Other then that you can put an S4 tranny on an S5 motor, and an S5 tranny on an S5 motor.

 

You would use a s5 flywheel and s4 clutch.

 

Clutches should be the same regardless of series.

Only difference being Turbo clutch and N/A clutch.

 

The splines are different.

 

i assumed and heard that they were counter wighted, ut then something confused me.
RB and other manufacturers sell light weight flywheels! does that mean you would have to buy the light weight counterweight and tear apart an engine for a "tranny" job!? that sounds rediculous.

 

If you put a light weight flywheel you have to use a auto tranny counterweight on it.

 

so if my new s5motor was auto i have to find an s5 flywheel and s5 standard counterweight??

 

The counterweights are weighted to the rotors, an s5 standard (front) counterweight should already be there.

But since you have an automatic flywheel you can get a lightweight flywheel and use your automatic counterweight.

 

okay thanks alot, but for now since used parts are cheaper can i use the stock standard s5 flywheel with the auto tranny counterweight??

 

A stock standard flywheel has the counterweight built in. You will not need to to attach any sort of counterweight at all.

 

I have a S5 auto engine with a FD flywheel and a S4 TII transmission. Everything is pretty much possible as long as you know the differences.