i was wondering if an s4 six speed trans will mate to an a4 2.8

 

Yes it will, but the gear ratios aren't ideal for the torque curve of the 2.8. Search has covered this in the past and you'll be able to find the prior threads about it.

 

i was also planning on getting a supercharger for it as well would that possibly bring the torque curve to a more suitable amount for the six speed gearing?

 

your looking to spend atlease 7k just as much as the car is worth

 

The supercharger should help a lot. From what I've read the gearing is well-suited to a torquey engine like that in the S4. The blower should help that quite a bit . Keep in mind that I don't think it's as simple as just a trans swap. You're likely to need the S4 axles, spindles, and quite a bit more as well.

 

Mate, yes. Work, no, not without alot more. You would need to swap out driveshaft, halfshafts, rear end, spindles, and shifter assembly. I'm probably missing something in there too.

 

Yeah you pretty much have to swap the whole driveline with the S4 2.7t 6 speed.
Other option would be to go with the 6 speed out of the B6 A4 1.8t.

 

makes more sense to buy a b6 s4 at that point