I'm trying to figure out what I should do to my 2004 S4 Cabriolet. It's a tiptronic, which is unfortunate, but it's what I'm working with. Can anyone please recommend upgrades for this specific type of S4, given it's a Cab with auto tranny?

- Would a supercharger even make sense with the auto tranny?
- Any exhaust upgrade recommendations?
- Any stock parts you'd recommend changing? I heard the water pump is shitty on this year S4.
- Other?

 

A supercharger should work well with the Tiptronic. Go to:
http://www.pes-tuning.com/
where you will find both a low and high pressure supercharger for the 4.2 engine. If they finally completed their development for the 4.2 engine, it may be ready now (the web site says availability started March, 2009).

PES makes supercharger and turbo kits for many other Audi models (also M-B, Porsche, VW, Bentley, Ferrari)

SuperSprint makes a cat-back exhaust for Audi's. Also race only downpipes. You will have to check about your specific Audi model. Go to:
http://www.supersprintna.com/

There is a great YouTube video on the S8 (my model) with SuperSprint installed. The sound is FABULOUS. Just enter, "Audi S8 Supersprint" and it should be the first video, or use this direct link:
http://www.youtube.com/watch?v=R4o9Shtnl3c

I just sent my ECU and TCM to AWE Tuning to have them flashed and rechipped for modestly more HP/torque, and faster shifts on the stock slow shifting Tiptonic. I will post a thread with results when I get them back.

When you do the timing belt, that is the time to replace the water pump on the 4.2 engine. Otherwise, you pay for a very expensive labor charge to get to the pump when that is already exposed when the belt is done. At that time, also replace any timing belt bearings or hoses that may be worn.