Hello all, Im new to the board and new to audi. Last month I purchased a used 01 a6 4.2 sport/premium pack. Living in Manitoba Canada I needed a sports car I could use year round and get me to where I need to be in extreme conditions. A wrx or evo would have been nice but this also has to be my everyday vehicle so the a6's comfort and quality level won hands down and I'm loving so much about the car. My question would be what is the best money to spend on this car in terms of performance? I want to replace the stock exhaust with something that will help performance as oppose to just sounding loud(luxury car) any recommended full set ups or would a custom built system be the way to go? As for tunes, I've exhausted the search feature on this one with horribly mixed opinions. Is there a tune besides something that I have to send my ecu away for that will give me a noticeable gain? what brand is best, unitronic? speedtuning?.....? other than that I have just a drop in k&n so far. ordering lightweight rims aswell. What about handling mods or other mods besides power adders that will make this car better over all? I'm an auto apprentice so I have access to a full shop and most tools I could need to do most things myself. I also have no crazy expectations from this car, I realize its a luxury sedan and not a tuner car. Just wouldnt mind giving her a little bump within reason(financially)
Many questions for one post I know...

 

When I got my 4.2 5 years ago I was also looking into tuning. Bottom line is there aren't many "reasonable" things you can do to this car. Many call it an Autobahn cruiser for a good reason. Sure you can tune the **** out of this if you really wanted but expect to drop 10 grand or so (5k+ for a supercharger, 3k+ for sport cams, 1k+ suspension, 1k+ software tuning). Another 3k+ and you can get a nice full exhaust system installed.
As you can see if you want to tune this beast you have to drop some serious cash into it and the increase is marginal compared to a twin-turbo setup (like the 2.7t).

Another thing you should consider is the weak transmission on the '01. Any tuning beyond stock is asking or pushing for a transmission failure (so I heard).

My recommendation is to restore the lost power to this car rather then tuning it. After 12 years there could be some hidden power you can easily get back with some maintenance. Look into a fresh set of spark plugs, coil packs, o2s and maybe even MAF.
Make sure you flush all the fluids and do an oil change since you just bought the car.

 

Thanks for the honest reply and kinda figured as much. Didn't even think of the tranny not supporting mods but that's a great point. I guess ill just have to spend money on cosmetics which is cool too, girls just like shiny and lots of buttons anyway and could give a crap about going fast fresh 5w40 synthetic oil change was just done aswell as i flushed my power steering . Haven't even checked the plugs yet tho but I wouldn't doubt they could be changed. Thanks again!

 

I have a 2000 4.2 and did a few upgrades to it over the years to try to get an extra bump in HP. I did a magnaflow cat-back exhaust, K&N air filter and a Unitronic stage 1 ECU upgrade. The items i got claimed to add a few HP here and there but the only real difference i felt was after the ECU upgrade.

Like Sheldon said; there aren't too many things you can do short of a supercharger ($6000 from PES tuning). One thing that I was considering having done was a JDM Motorsports S8 upgrade. Apparently you can get S8 headers and cams etc..for $3000 which should make a considerable difference in HP. I've been talking to a few guys out there about having this done. But again; the basic stuff as mentioned above ( new plugs, coil packs maybe adding a Walbro fuel pump) should keep you pretty quick. The 4.2 is still a beast!