I am a competent mechanic and I do not know enough about tuning these Audis. I just bought a 2001 A4 Quattro and I have some questions.
What is the stock boost?
What is a good boost to stay at when tuned?
What are good ECU options?
What are some normal mods for these cars?
What is the difference between the S4 and the 1.8t (motor size, type, transmission, specs)
What are good injectors for this car? What do they run?
Does a turbo swap (T28) require a larger fuel pump or is the stock large enough?
That is all for now...I'm sure I will come up with more