What does a supercharger do to your car?

Answer 1

It increases the hp/torque of the engine by increasing its (VE)volumetric efficiency. It does this by force air/fuel into the engine under great than atmospheric pressure(boost). Boost is Absolute pressure(coming out of the supercharger-atmospheric pressure(14.7psi aprox.) Absolute pressure/atmospheric = P/R Theoretically how many times more air the engine is seeing.

An example:

a 302 v8 that normally has a V.E. of 80% = only 241cuin. of the engine is filling per complete cycle. BUT with a supercharger running at 7.5PSI (boost) 1.5p/r =361cuin is consuming/ 50% more= a possible 50% increase in power. I say possible/theoretical because compressing air heats it, causing a reducing the increased amount. air to intercoolers and alcohol injection can get it close(90%) to the potential output, only air/water with ice can get at or above the estimate. So a 300hp 302 with a 7.5psi intercooled kit should get close to 450hp, probably 435hp is more likely, for a 135-150hp increase.