im looking into getting another integra soon (should have never sold my first one). going to eventually go with a turbo setup. just messin around i looked on ebay to see what t3/t4's were going. i saw alot of turbos with .50 A/R with .63 turbine. i was just thinking it sounded a little big for a like a 10 psi street setup. i think i've heard a more streetable turbo is like a .48 A/R with .50 turbine. i Figured there trying to sell the big turbos to all the kids wanting to run 25 psi of boost on there lil stock civic engines or something. let me know what you guys think.

 

ttt

 

i am going to use a .63 a/r. I use to have a .48 ar

 

You are confusing psi with power. psi can at best be a halfassed yardstick for engine/turbo setup efficiency, and you shouldn't think of psi figures out of the context of "7 psi got me 220 whp on my specific setup."

Big compressors make more power per psi due to efficiency and charge temps - cooler air is denser. Cooler air is also safer on your engine. ~7-10 deg F increase in intake charge ~ losing one point of octane in your gas.

Big turbines cause less exhaust pressure in the manifold, which increases the flow through the head, and how much power you make per psi. It is very much like going from a restrictive OEM exhaust manifold (stock CRV, perfect example) to a good header on a NA car... you can get air in/out easier.

If I were to run a generic fuel map baseline I have for a B16 w/ a T3/4 that has a .63 turbine AR... aftermarket T3/4's have stage 3 turbine wheels, according to Turbonetics nomenclature, versus the OEM car's stage 1... on a B16 with an OEM .63 turbine AR, the damn thing runs great off boost but bogs with fuel in boost. The exhaust gas piles up and creates enough pressure to kill off flow through the engine... as compared to a different setup with the "same psi."