NCTURBOS said:Not a true comment. Sometimes "new" doesn't make it better.
That's good performance. We've had cars run 11.3x-11.5x with very similar bolt-ons, but at 24psi.
My experience with the GT61 is that if you were to turn it up from your 23psi to say 26psi you would either gain nothing or lose HP. Whereas the Ta/Te61 would continue to gain and outperform the GT61.
K.
I think that is more a function of the exhaust wheel and not the turbo itself. I have several videos of EVOs making over 600 whp with GT-35R turbos which uses the same compressor wheel and only 2.0/2.3 liters engines.
I'm confused by the fact that a TA/TE-61 can make more power in the upper boost range unless you are comparing it to the GT61 turbo mentioned using a 31E wheel. I'm sure one with a 52 wheel and S cover or larger exhaust wheel would not experience what you are describing. The only way to find out is to test one on a GN at 25+ psi. I have accidentally hit 23-25 psi and the car felt anything but like it slowed down, but I have a different exhaust wheel.