Originally Posted by DJF(NJ)

I've run a ball bearing TO4E, 60 trim with a 1.0 A/R and am quite happy with it on the streets. Very responsive on and off boost. 3.5" DP>3.5" MP>3" catback. If I'm cruising in 5th gear and go WOT at 2000 rpms, I see 10psi at 2300-2400 rpms. This is with a 4.3 rear. It's sweet spot is about 8psi-15psi. Yeah it's an old turbo design but suits me well. Never autocrossed it with the single but did so on the twins. While the response and torque of the primary turbo at low rpms is hard to match...I never liked the flatness on the small straightaways waiting for the 2ndary to come on. Always seemed like just as the 2ndary was exploding online I was either lifting and/or braking for a turn. Of course, course setup plays heavily on that. My car is right around 375 to the wheels at 14 psi. With your goals a 57 trim TO4E would work well also. Though of course, there are other factors associated such as motor condition, tuning, etc. my 2 cents.