Gearing Calculator
Gearbox, Diff, Engine simulator. Helps you figure out RPM, road speed and optimal shift points.
Inputs
Results
RPM vs Speed
Tractive effort
Engine curve
Optimal shift points
Where the next gear starts pushing harder than the one you are in. Equivalently: where the revs you drop to make as much power as the revs you are leaving.
Top speed per gear
Shift points
Lap map
Load a RaceChrono Pro CSV export (Format 3) to trace a lap. No data is collected, calculation is done in browser.
Shift strategy
The map runs your lap's speed trace through each setup's gearing.
- Upshifts: happen at the input Shift at RPM, like the shift trace above.
- Downshifts: wait until the lower gear pulls harder; using the same tractive-effort crossovers as the Optimal shift points table. A taller gear that is still the stronger one is held.
- Corners: above of lateral load the downshift waits for the car to unwind. Upshifts still fire.
- Shift time cost: if a downshift cannot repay the down-and-back-up cost (2× Shift dead time) before the revs recover, then hold taller gear.
- Never use 1st gear.