i was wondering, because i am stuck with the 12V AAH engine if it was possible to swap it for a 2.7t, would the transmision and computer be able to handle the new engine or would i have to swap them out also? how much do you think it would end up costing

IM new soo dont take just my advice but im pretty sure you need a new transmission,computer,along with other things...in my opinion way to costly a used s4 engine by itself with no turbos is like 3500 so go with the supercharger if thats to rich for your blood try a remote turbo charger
http://www.ststurbo.com/universal_system
peaces and just my 2 cents(ask them about turbo lag and that stuff to)

you would have to swap out so many things it would end up costing you less if you just bought a new audi

id said it cost atleast 10k

yep, ether supercgarge your curent, or remote turbo, or nitro for short burst of power (check state law).

I had an Idea like 1 week ago, I wana get 2 cars more. get audi 80/90 AWD any year. and get another audi with 3.6 or 4.2L engin and AWD manula as well.

then rebuild the V8 and SC it to make in area of 600HP to 1000HP, and stick it in the 80/90
rollcage the car, move battery and rad into the trunk. Fiberglass the body where it wong compromise the integrity or safty, so roof and front doors stay as they are. everything else be fiber glass and carbon fiber.
then have fun........
also engine from the audi 80/90 stick back into the car that I pulled the V8 from and use it too.
then have more fun.........

I know a guy that did a a4 2.8 to s4 swap and almost everything needed changed (engine, trans, ecu, wiring harness, rear axle, etc.) He had an insurance totalled s4 that was the donor car so it wasn't too bad. But if you want to do it right, I'd get a complete donor and part out what you don't use. Wrecked S4's are uncommon but I've seen quite a few go through the auction.