Drag racing calculators
Explore empirical ET estimates, time-slip consistency and air density.
Quarter-mile ET
Explore empirical quarter-mile elapsed-time and trap-speed estimates from race-ready weight and engine horsepower, with visible model coefficients.
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Trap speed
Estimate quarter-mile trap speed from race-ready weight and engine power using an explicitly empirical cube-root model.
Open calculatorET to horsepower
Invert an empirical quarter-mile ET model to estimate effective engine horsepower from time and race-ready weight. This is not a dynamometer measurement.
Open calculatorEighth to quarter mile
Scale an eighth-mile elapsed time using a user-selected conversion factor. The default 1.57 factor is a heuristic, not a validated prediction for every vehicle.
Open calculatorDial-in worksheet
Summarize three measured passes with mean, spread and standard deviation, then add your chosen margin to form a planning dial-in.
Open calculatorDensity altitude
Estimate moist-air density and corresponding standard-atmosphere altitude from measured station pressure, temperature and relative humidity.
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