seems like this thing would drive like a V8 haha.
i think its near impossible to have a turbo be as responsive as this and make decent top end.
the small rear housing will refuse to hold high boost at high rpm, therefore peak power at 5,000 odd.
but peaking at 5,000 i think seems a waste of the revving nature of the RB.
truly a street turbo; lots a power in the early rev range, but with no top end.
would be interesting to see how you go with boost control.