HAHAHAHAH, I am pretty sure 10 psi on one turbo, is equal to 10 psi on ANYTHING else. at 10 PSI on a small frame turbo, it is moving ten pounds per square inch of air, at 10 psi on a large frame, it is moving 10 POUNDS PER SQUARE INCH. The difference in turbos will affect what PSI it can reach and how fast it will get there, in simple terms that is
Did you read this?
Psi doesnt mean anything its waht CFM the turbo can push that matters, so 10psi on a small turbo is different than on a bigger one.
And how about this?
It is indeed different; because even though it's 10psi, it would be in a different RPM band/different efficiency.
And what about this?
Byron hit that nail on the head.
K2e2vin's advice was spot on, but I'll add that the best way to pick the pressure is with a horsepower goal. To find your horsepower goal look at other cars and what their power to weight ratio is. Find out how much power it will take to get your car to the same or better p/w ratio.
So, in your own words, HAHAHAHAHAHA!