Explain HP vs. Torque

torque (tq) is the twisting force an engine makes. if you were to put a 1 foot long wrench on a bolt and put 100lbs at the end of the wrench, that equals 100ft/lbs.

horsepower (hp) is the multiplication of torque using revolutions per minute (rpm). the mathematical equation for hp is (tq x rpm)/5252.

so 200ft/lbs of tq at 5000rpm = 190.4hp.

you will always have more tq than hp below 5252rpm. you will always have the same hp and tq at 5252rpm, and you will always have more hp than tq above 5252rpm.
 
Torque is the twisting force imparted to the crank flange and then transmitted to the transmission and the rest of the drivetrain. To some degree torque is the grunt that gets things moving, and horsepower is the force that keeps things moving. An engine is most efficient at its torque peak, wherever that happens to occur. Below the torque peak, engines generally have more than enough time to fill the cylinders; above the torque peak, they don’t have enough time to completely fill the cylinders. This is generally beneficial in that it lets engines produce most of the desirable grunt work (torque) at lower engine speeds, which means reduced wear-and-tear and better fuel economy.

Because torque and rpm are divided by 5252, torque and horsepower are always equal at 5252 rpm. If you solve the equation at 5252 rpm, the rpm value cancels out, leaving horsepower equal to torque. If you plot torque and horsepower curves on a graph, the lines will always cross at 5250 rpm (rounded off). If they don't, the curve is undoubtedly bogus.

Torque = HPxRPM(at whatever RPM you measure it) / 5252 period