Originally Posted by socceralchemist911
now wich one is faster?
Absolutely stock, the 2.8 is more powerful and fractionally faster.
Its tuning options are limited - though if you want to throw a few grand at it, I think PES still make a supercharger kit for it (G2).
Provided its a Quattro, S4 cat back exhausts should fit too (on B5s), which opens up exhaust options potentially... Depends if they sound any good!
The 1.8T has plenty of tuning options available including several turbos for upgrades (not just the K04), and numerous tuning and exhaust options. Any moderately modified 1.8T will be quicker than a 2.8.