Do you know where I can find specs on the T3/T4 units? I want to plug them into Desktop Dyno and play around with how they affect output. DD isn't very good with forced induction, but I can at least see what the trend is for different combos. Specifically, I'm looking for flow, surge flow, efficiencies, and anything else I can find.
I agree with what you're saying about increasing the current curve, but if you look at the dyno chart above, adding torque isn't a real issue. I want to extend the powerband to the right. Maybe not add torque, but at least extend a flat band out as far as say, 3500 or 4000. That will bring HP up to the 500 area and that would make me happy.
The current combo is 8.7:1, but that's with slightly milled heads. I could go back to stock heads and get about 8.4, but I only want to run about 6-7 intercooled psi or less. I have no problem running 91 octane. Its all expensive here in L.A. so what's a few more bucks?
So, you were talking about painting the curve with the wastegate. Can I choose a smaller turbo to get boost sooner, then 'gate off the pressure to keep 7 psi all the way to 5500? Is that how its done, or does that introduce too much exhaust backpressure from the small housing required to do that?