Stop in for a cup of coffee

dukeboy_318 said
For example.

450 ft lbs @ 4000 rpms

H = 450 * 4000 / 5252

H = 1,800,000 / 5252

H= 342.8

Where you're getting confused is the 5252. That's not the RPM, that's the fixed divisor

So while your rpm can be 2000 or 3000 or 4000, the 5252 stays constant in the formula, the rest of the numbers will change

I get that the 5252 is a constant (and almost understand where it comes from!)... If you plug in 2626 as rpm with a 5252 divisor, you will get 1/2... Which would always equate to HP being half of Torque at 2626 RPM...