Ralph

I would be curious to see the power difference between the 0.81 and the 0.59 A/R turbine housings. The smaller turbine housing will spool up a lot quicker but you will loose a lot of power at higher boost levels. Post some more numbers when you get them!

On an SR20 with a T3/T04E switching from a 0.63 to a 0.82 A/R turbine housing yields about 80 hp at 19 psi. The gain in power on your straight T4 should be even greater.

Are you looking for all out power or is it going to need to be more of a street car with less lag?

Nice job on the manifold and install. I like the polishing.

Peace