i just bought 2003 A4 1.8T Quattro with 65,000 miles. im new with Audi and new in this forum. after reading much information about the A4. i was wondering what are the common upgrades to do to increase horsepower with minimal financial consequences and damage to the originality of the car? what does the BOV do to the cars horsepower? thanks

 

Over in the B5 section they have a couple FAQ stickies that will answer all your questions. It's the same engine.