Thanks guys- lots to think about here.
The intake and intercooler will remain, irregardless if the supercharger used.
Rich, isn't the air in an Air Cycle Machine compressed by a centrifugal pump? Dad was an airline mechanic, and ACM's were part of the planes systems, so I'll explore this idea with him tonight!
Buddy, you thought it was a simple question right? As has been pretty much stated here it's not quite that simple! It also includes the 2nd law of thermodynamics!
Rule of thumb: (0.00436 * PSI * CFM) / efficiency = HP to compress the air. So all things being equal (NOT) then efficiency is the short answer.
Roots 50%~55%, spiral ~68%, centrifugal ~69%, screw ~72% (Whipple claims higher!) and the odd duck Comprex ~84%
http://www.modified.com/editors/0705_sccp_comprex_compressor_supercharger/index.html
Just when you thought you knew it was safe to get back on the salt!!
Woody, it appears there isn't any, or at least I can't find any, empirical data on the HP it takes for each style of blower to make the needed boost.
You're equation, along with the efficiencies, may be as good as I have to work with.
As for the second law-that's why I have the intercooler!
That being said, it looks like the screw compressor wins out, followed by the centrifugal. I wonder though, how much efficiency is added by the teflon stripping in my huffer?
I have the Procharger D1SC, and don't own a screw type, so I'll probably play around with it this winter, to see if I can get any gains out of it.