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Horsepower from ET Calculator
Estimate horsepower from weight and elapsed time
Horsepower from ET estimates an engine's flywheel horsepower from the car's race weight and its quarter-mile elapsed time.
Formula: HP = Weight × (5.825 ÷ ET)³
What this number means
This estimates flywheel horsepower from your car's weight and quarter-mile ET. ET-based power reflects the whole package — traction, gearing and launch included — so compare it with the MPH-based estimate: the gap between the two numbers tells you where the car is winning or losing.
What to change next
If this number is well below your MPH-based estimate, look at the front half of the run: launch, gearing and converter before adding engine power. If both estimates agree and are low, the engine itself is the next place to look.
Worked example
A 3,200 lb car (with driver) running 11.50 in the quarter gives ≈ 416 hp.