What kind of supercharger is on a 1999 Pontiac Grand Prix GTP?

A 1999 Grand Prix GTP uses an EATON M90 supercharger that displaces 90 cubic inches of air during every revolution.

This results in a rating of 240 horsepower at the crank at 5200RPM, and a "pavement pounding" 280ft-lb of torque at 3600RPM!