Can I use a stock s4 TII flywheel when I swap the TII drivetrain, or do I have to buy an aftermarket lighter one?

 

So are you swapping out a TII drivetrain for something else or installing a TII drivetrain and want to use a TII flywheel?

 

You never have to buy an aftermarket flywheel.

 

im guessing you have an n/a... you're not very clear...

If you use a t2 drivetrain you need the t2 flywheel that balances your engine.

in otherwords youcould end up with an s4 car with an s5 TII tranny, an s4 TII driveshaft, but since you still have an s4 (n/a) engine, youwould need the stock (or aftermarket) s4 tII flywheel.

Actually this raises a good point:
does the balancing of the s4 n/a and S4 TII differ? I would guess not, but im not sure now that i think about it.