Bigger Blowers. How much gain?
 

Heres a question a friend and i have. First i will list my engine specs.

454CI
177 weiands (525sc blowers).
blowers driven at 2.17:1 ratio, they make around 5psi.
no intercoolers.

His.
502CI
250 series blowers
no intercoolers.

I understand that spinning a larger blower, will cool the intake charge, therefore reducing chances of detonation. I guess what I am asking is, how much power is there to gain just by adding a larger supercharger? Say if i run a larger blower on my 454, say a 250 series like his, at a 1.5:1 ratio, which according to the chart i have, would make around 7-8psi on a 454. Obviously more HP from the added 2-3psi, but is there more on the table since i'd also be spinning the 250 series blower at 1.5:1 vs. my current 177 at 2:17:1? I suppose this theory will apply to all, but lets use mine as a example :drink:

You should be making about 6# of boost with 2.17 overdriven on the 177. At least that is what it would make on a 525SC.
If you went to a 250 on your engines at the same 6# of boost, maybe a 15-20hp gain due to the cooler charge. Add another 15-20 hp if you turn the boost up to 8# with the 250. With more boost, you push yoursel into haveing to a race fuel mix, but that depends on your static comp ratio.