Datalog analyzer for back-solving gear ratios

Paste RPM and speed data from a datalog to detect gears and back-solve your ratio stack.

RPM + Speed Data

Paste CSV, tab-separated, or space-separated columns. Expects RPM and Speed values.

Speed unit:

Known Values

Optional. Provide what you know to refine results.

Final Drive Ratio

If known, individual gear ratios will be back-solved.

Tire Size

Width

Aspect

Wheel

275/35R20 — 731 rev/mi

Expected Gears

Leave blank to auto-detect from data clustering.

How It Works

Each gear has a constant relationship between RPM and road speed. This tool groups your data points by that ratio to identify which gear each point was logged in.

Effective Ratio = gear ratio × final drive. If you provide the final drive, individual gear ratios are back-solved.

Best results come from steady-state pulls in each gear (WOT or cruise), not during shifts. More data points per gear = better accuracy.