On one hand, parasitic loss is not your friend. Sure, some degree of it is necessary to operate vital components that the engine can’t operate without, but the less you can get away with, the better. But much like in the business world where they say it takes money to make money, sometimes it takes losing some horsepower to make power.
In no case is this theory more true than superchargers – be it of the roots or centrifugal variety – that operate with a belt or chain right off the tongue of the crankshaft. It takes a lot of power to get them spinning at a point where they can make that power-producing boost, and that means the hamster inside the wheel has to work a little harder to keep things operating. and therein lies your parasitic loss. By utilizing a supercharger, you certainly gain back the horsepower that’s lost in spades, but just how much power does a crank-driven supercharger consume, exactly?
Steve Morris of Steve Morris Race Engines, who’s been featured here on DRAGZINE on countless occasions, performed dyno tests using a ProCharger F-1R and F2 supercharger, with the goal in mind of scientifically determining the parasitic losses placed upon the engine.
With the F-1R tested at a range of 36,847 to 54,080 RPM, the parasitic losses upon the engine worked their way from just 50 horsepower with 10.1 pounds of boost up to 136 horses at 21.7 pounds. Meanwhile, the F2, at a range of 36,755 RPM (11.7 lbs) to 61,264 RPM (32.9 lbs), the losses climb from 75 horsepower up to 353 horsepower. That may seem like a lot of power to give up on the surface, but it’s actually quite efficient, and again you’ve gotta give some to make some.