Is there any sort of supercharging kit for a 2005 Audi S4, if not, what is a good power adder for this car?

Answer 1

Yes - http://www.mtm-online.de/en/index.php?nav=3&FZID=S4B6253Q&Kitnum=M1S4344450QX

Obviously, a supercharger is going to void at least your engine warranty, and being that it's an Audi, you may really want to think that one through (had an '02 S4 that just about lived in the shop).

It's a normally aspirated car - you're not going to easily add power without forced induction or nitrous, and adding nitrous to a car like an S4 is moronic. Adding CAI + exhaust + software might net you 30 hp or so, but will also cost in the $3500 range. You probably realize there's no way to turbocharge it without repiping the exhaust system, which will be ridiculously expensive.

But, to be frank, the S4 has plenty of power; its weaknesses are braking (due to its weight) and handling (body roll). You'd be much better served addressing those areas first.

Check out AWE tuning in the States also.

Answer 2

An APR chip is a good small start....the thing already has like 250 hp with the chip u might get an added 20 hp

Answer 3

Without going into a lot of expense putting a turbocharger in it, you can look into getting a performance chip(computer) at a performance parts store or reprogram yours.

Answer 4

APR is a good Chip
You can also replace the intake and exhaust