Paolo Castellano
Enthusiast
I have a question about how much horsepower can be had from each additional lb of boost. I realize superchargers have inherent parasitic loss when compared to turbos. Someone gave me this equation to calcuulate the relative power gain as the following: 29.92 in Hg + #lbs boost all divided by 29.92 = factor to multiply current hp/torque. Here is an example: 6lbs of boost + 29.92 = 35.92 ==> 35.92/29.92 = 1.2 ==> 1.2 X 420 RWHP = 502RWHP or 82 RWHP. 12 lbs boost should yield 164 additional RWHP or 588 RWHP in this example. I remember Dan Black's Doug Levin car made 617 RWHP and 676 RWLbs/ft. Does that mean he is running 15 lbs of boost? 15+29.92 divide by 29.92=1.5 ==> 1.5 X 411RWHP = 617 RWHP and 1.5 X 450 RWlbs/ft = 675 RWlbs/ft. These #'s are for a stock car( ie no headers/exhaust/etc...)Can it really be that simple to calculate? Would a turbo application yield more RWHP due to less or no parasitic loss? Doug and Jason chime in any time you like! I would also like to see a dyno sheet for the supercharger applications in addition to the peak #'s, this would be helpful to map out HP & torque gains throughout the entire range of RPM. Also do you guys have an idea of exactly how much boost your systems are making at any given RPM? Paolo