So, I am totally new to Audi's. I drive a Mustang GT with a significant number of suspension mods. While I love the Muscle Car sound. Id be willing to trade it for a Tubro Blowoff. So, I want to know, if I upgrade the turbo and piping, what kind of boost can these cars take? Is A4 or S4 going to be the better car, or the A6? I want a track car, not a drag or rally car. I really like WRX's but I think I'd rather have an Audi. Tell me, what is the max PSI I can run on this thing? and what kind of power will I be making with that?