The formula, if memory serves me correctly, is TorqueXRPM divided by 5250=HP. Also, from my days working with Dyno's, it is possible to increase torque and have less HP by moving the max torque down in the RPM band. The opposite is also true, as in less torque - more HP as long as the torque is moved up the RPM scale enough. One such application most people are familiar with is the diesel. Some of the new pickup trucks with diesels are making upward of 650 ft/lbs of torque and their HP is less than a comparible gasoline engine. An example - 400 ft/lbs of torque X 2500 rpm's divided by 5250 = 190 HP. Second example - 300 ft/lbs of torque X 4000 rpm's divided by 5250 = 228 HP. Second example less torque more HP. [8D]