Douglas' 250 made 700 HP w/7 psi of boost pressure.

There are so many variables,to think about, there is not just one formula.
My 62-1 turbo is good for 625 HP flows up to about 60 lbs per/min
http://www.turbocharged.com/catalog/compmaps/fig10.html

Nice project BTW


MBHD

12 port SDS EFI