FI: M45 Supercharger overspun to 16,000 rpm w/ BSP Air/Water Intercooler

If you are looking for more power than the Eaton Supercharger can normally give you then you need to spin it faster. I do this with a BBK Pulley overlay and a Tony Pulley. The combination of the oversized BBK (crankshaft) pulley and the undersized Tony (supercharger nose) pulley increases the boost pressure by increasing speed that the supercharger spins for a given engine RPM.

This calculation shows pulley dimensions and how fast the Supercharger RPMs will be at redline (7200 rpm):

Crank Pulley SC Nose Pulley Ratio Max Blower RPM
Stock (130mm) JR 1.6 (73mm) 1.78:1 12,816
BBK (150mm) Tony (67.5mm) 2.22:1 15,984

See how the BBK pulley overlay has a larger circumference than stock crank pulley:

Also note how the Tony pulley has a smaller circumference than the stock nose pulley:

Spinning the supercharger so fast not only increases your boost pressure (from 6 psi to 10 psi) but really increases the temperature of your intake air. To bring temperatures back to normal (high temps cause engine killing detonation) I use a Brain Storm Products Air/Water Intercooler:

The intercooler gets its water supply from the radiator overflow bottle and it recirculated through the intercooler and a small radiator that sits in front of the stock engine radiator. Here you see me modifying the overflow bottle:

Note the inlet and outlet hoses now on the bottle:

The intake manifold and the JR "hood rubber" outlet (so large that it rubs the underside of the hood while you drive) have both been ported and polished.

Here's what the hood rubber looked like before:

And here's what it looked like after a ton of elbow grease: