According to Gates V-belt design criteria the max horsepower per 3V series belt is 7.01 at 3,450 RPM. Go faster under load and the belt will suffer.
A GM power steering hydraulic pump draws three to five horsepower depending upon load and RPM. Doing more research and actual dyno comparisons rate it at 6.6 horsepower to spin pump on a Mopar. Ford had the same numbers as the GM pump.
Because a car can rev beyond the 1917 designed RPM limits placed on a V-belt more than one belt is required for safety. That is why GM used dual pulleys on power steering pumps on all medium to full size cars (lighter car has less load on the pump so it can use a single groove pulley).
Last edited by Big Dave; 08-06-2016 at 10:39 PM.