I'm not quite sure what you're trying to acomplish...From what school has taught me its the Velocity of the gas that has the biggest impact on spool. Combine that with Volume, and you're in happy land. Velocity is proportional to heat and heat to energy.

 

That hybrid set-up involves a lot of time and $$ as well. As Jacobcartmill said a cheap cast T04 manifold, T04 60-1 and ext. wastegate is going to cost as much and have more top end HP potential. Forum members are making over 500 rear wheel hp on the aforementioned set-up, my hybrid probably maxes out ~400RWHP.

The only thing I had going for me was spool-up, but I downsized my turbo back exhaust size to 3" to stop boost creep and spool-up suffered. I am going to try the 3 1/2" downpipe to 3" rear section to see if I get better spool-up and still restricts the top end enough.

Just get a T04 set-up w/ a small(ish) hotside and put a 3 1/2" or 4" turbo back exhaust on it for good spool up.

 

On a turbo the pressure differential between the engine side and the exhaust side will have a tremendous impact on spool up.

That is why the huge 3 1/2" and 4" exhaust work so well to provide the low end torque as boost comes on very early.

 

Ok so a .84 tang divided T04 it is, could someone tell me what E or B compressor wheel would give me 300-350 at 15psi?