Torque is a unit of measurement that expresses the amount of work done. It can be listed in foot-pounds, Newton meters, or Joules.
For example, imagine using a wrench with a 2 ft. handle. You apply 50 lbs. of force to the handle. You are applying 100 ft.-lbs. of torque. (50 lbs. x 2 ft. = 100 ft.-lbs.)
When an engine is listed at 200 ft.-lbs. of torque, it means 200 lbs. of force applied to a 1 ft. lever would be needed to stop its rotation.
How is it measured?
- Engine specs will list peak torque at a specific rpm.
- A dynamometer (dyno) measures the amount of torque an engine applies.
- The formula to calculate torque is:
(5,252 x Horsepower) ÷ rpm = Torque
For example, if an engine has 240 hp at 3,880 rpm, it would be:
(5,252 x 240) ÷ 3,880 = 325 ft.-lbs.
- The difference between torque and Horsepower is that:
- Torque explains how MUCH has been accomplished.
- Horsepower explains how FAST it's done.