How to Calculate Torque Rise

Torque rise gives your engine extra power.

When your tractor hits rough ground and starts to stall, the engine often gives an extra kick to keep it running. This extra power is "torque rise," or "backup," and the more you have, the more power your engine can deliver. Calculate torque rise from peak torque and torque at the rated speed.

Things You'll Need

• Calculator or computer

Instructions

1. Subtract torque at the rated speed from peak torque. For instance, if your engine delivers 500 pound-feet at the rated horsepower and speed by 600 pound-feet at peak torque:

   600 - 500

   = 100

2. Divide your result by torque at the rated horsepower and speed:

   100 / 500

   = 0.2

3. Multiply your result by 100:

   0.2 * 100

   = 20 percent

   This answer is your torque rise.

Tips & Warnings

• If you don't have a calculator handy, use your computer's calculator.

References

• Texas A&M: Understanding Tractor Horsepower and Torque

Resources

• University of Maryland Torque Rise presentation
• Rental HQ: Understand your power-source options