On my last TT, I had t-28s, which came w/ the car. My passenger side turbo froze while I was breaking in my clutch. I had it set to 15 psi, but I wasn't really boosting b/c of the new clutch. My t-28s never went past 17psi. The last owner(MyWhiteZTT(NJ) had a dyno sheet, I beleive it made 420rwhp and 398rwtq.