Im sure its been answered before and i couldnt find my answer in the search.

What i am asking is, will there be a performance difference if I use an S4 turbo, tranny, and rear end with an s5 motor?

 

other than the sway bar links being different styles and the half shafts are a little bit different theres not much else that i know of.

 

Only difference you will really have between the parts is the LSD in the rear end. The S4 has the clutch pack and S5 got the Viscous. Now I think I remember something about the 87 turbo trans having a few different parts for the first half of the production year something about it being a little stronger or something. I could be wrong and thinking of the NA trans but im pretty sure its the turbo trans.

 

The only difference you will notice:

*you can accelerate off of 5th gear with the TII transmission
*If your N/A came with a 3.9, the 4.10 final drive from the diff will help you accelerate quicker
*TII has LSD, N/A (unless GTUs) came with open.

 

so the answer is yes, but with some minor differences

 

you will need the crossmember off the S5 transmission and the S5 half shafts, the S4 half shafts will not engage the viscous unit on one side, you will be able to drive the car but it will have a mean pull to the right because only one drive wheel will be working right.

 

Can you explain a bit more on this? Wondering how half shafts affect lockup characteristics of a differential.

 

easy, the drivers side S4 TII half shaft stub end is too short inside the differential to actually engage the gear case, so the half shaft spins freely on the driver's side when you put a torsen diff carrier in it. basically you can't use the S4 half shafts with a S5/6 torsen diff because they are too short. although it feels like it is fully in the diff case, it is really just floating in there, doing alot of nothing.

 

S4 turbo has to be used with a S4 manifold...

 

yes the s4 turbo would also require a way to control the twin scroll actuator if you want to use it properly. You'll need a vacuum solenoid, check valve, and an rpm or other type of trigger to control it. The s4 wastegate is inferior so it would take porting just to match an unported s5 wastegate in terms of flow.

 

OP is talking about the DriveTrain ..not the actual Turbo Swap itself.

 

Ohh ok, you are talking about using S4 TII DIFFERENTIAL STUB shafts in a S5 TII differential. For a second there the wording made it sound like using the actual CV half-shafts from an S4TII on an S5 TII would cause issues, which wouldn't make sense.