Heres the deal. I just bought a 98 A4 Quattro. Its a nice ride. Anyway, I'm taking it to the shop to get some exhaust work done. 3 inch from the flex pipe back, mandrel bends, and hi flow muffler. The reason why I choose 3 inch is mostly because it sounds really good on a turbo 4 cylinder. I'm into DSM's also and the Audi is just gonna be my nice daily driver. What kind of gains did you see with a similar exhaust setup. JW.

 

3in is piping is extreme overkill for the stock turbocharger. Your low end will be greatly decreased.

 

Does exhaust work (say 2.5 inches) only yield gains with a chip or aftermarket turbos?

 

With a good 2.5in system on the stock turbo will open up your car pretty well. with no other mods i have heard of up to 15hp @ the crank. That is a cat-back exhaust which includes downpipe and full system with high flow turbo mufflers. 3in is a little big for stock turbo, you still need some back pressure.

 

I don't care about low end. Besides, the turbocharger on an 1.8 is so small that is hits full boost at like what 2500 rpm. Maybe less. Also, if I lose all this low end power then it will just hit harder once I hit full boost which equals more fun.

 

Alright, if you think you know what your talking about, have fun.

 

thats overkill on the stock turbo. go 2.5 and youll be good

 

i run 3" on my t3t4 i would say max 2.5" on the k03

 

... Mmmm... I've never really had a problem running 3" Exhaust on stock Turbocharger (Then again, stock DSM 14Bs can boost 23psi stock)... But I'm not sure if these cars are different, so I'd say keep it mild for now, and 2.5" should do just fine until you start swapping Turbochargers.

 

Is 2,5' enough for K04 ?
or 3' is better ...