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MPH Predictor Calculator
Predict trap speed from weight and horsepower
The MPH predictor estimates a car's quarter-mile trap speed from its weight and flywheel horsepower.
Formula: MPH = 234 × (HP ÷ Weight)^⅓
What this number means
This predicts quarter-mile trap speed from weight and horsepower. Trap MPH tracks power-to-weight closely, so it is useful for choosing gearing before a car has ever made a pass.
What to change next
Feed the predicted MPH into the gear-speed table to pick a rear gear that crosses at your target RPM. If actual trap speed falls well short later, check weather, tune and converter slip against this baseline.
Worked example
3,000 lb with 450 hp predicts ≈ 124 MPH trap speed.