Rear Wheel Torque Conversion Guide
Rear wheel torque is torque measured after engine power passes through the transmission, final drive, axles, tires, and dyno rollers. It reflects what the vehicle can apply at the road. Flywheel torque is different. It estimates crankshaft torque before drivetrain losses and gearing multiply output.
Why This Conversion Matters
This calculator converts rear wheel torque into flywheel torque by removing gear multiplication and efficiency loss. It also supports unit conversion. You can enter pound feet, newton meters, kilogram meter, or pound inches. The tool returns corrected torque, wheel torque in base units, total ratio, drivetrain efficiency, and estimated loss.
Input Accuracy
Accurate inputs matter. Gear ratio and final drive ratio create large changes. A high first gear can make wheel torque look huge. A direct gear near one to one is better for comparison. Drivetrain efficiency also matters. Manual drivetrains often lose less torque than automatic or all wheel drive setups. Use a value that matches your test condition.
Formula Meaning
The formula is simple. Flywheel torque equals rear wheel torque divided by gear ratio, final drive ratio, and drivetrain efficiency. Efficiency must be entered as a decimal effect. This page accepts loss percent, then converts it to efficiency. For example, fifteen percent loss becomes zero point eight five efficiency.
Practical Use
Use the result as an engineering estimate. Real vehicles include tire deformation, converter slip, clutch slip, roller inertia, temperature, and calibration differences. Dyno figures also vary by correction method. Because of that, this tool is best for planning, comparison, and workshop records.
Reports
The CSV button exports a clean row for spreadsheets. The PDF button creates a compact report for sharing. Both include the inputs and calculated outputs. Keep the downloaded files with dyno sheets, gear notes, and vehicle setup notes. That habit makes later comparisons easier. It also helps technicians explain why a torque number changed after tires, gearing, transmission service, or drivetrain repairs. For best results, record ambient conditions and selected gear. Repeat the same setup during future tests. Small changes can shift torque estimates. A consistent process gives the calculator better value. It also makes exported reports useful during tuning, troubleshooting, conversion work, and performance review after important vehicle changes.