turbo turbine wheel trim number

[fush]

Can anyone give me any insight on the wheel stages on a t3 exhaust side. I am trying to choose between either going with a bigger a/r or going with a bigger stage wheel with the smaller a/r.

 

I have been told that a .63 a/r with a stage 3 wheel will actually flow more than say a .82 a/r with the normal -72 wheel. But even with the bigger wheel that can flow more the smaller a/r will still create more back pressure?

 

I assume modifying both of these will change the spool time I am seeing but this project will see relativly low boost so I am trying to find the combo which will spool as quick as possible yet still flow a proper amount of air.

 

A little background if anyone cares I am looking at a t3/t04E 50 trim, with .63 a/r and stage 5 wheel on the exhaust side. Trying to come up with a cost effective mod which should out perform all the n/a mods that one can do to the vr6 engine and also cost less.

 

-jeff