HP Weight ET Calculator

Quarter-Mile ET Formula:

\[ ET = \left(\frac{W}{HP}\right)^{\frac{1}{3}} \times 5.825 \]

Quarter-Mile ET (seconds):

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1. What is a HP Weight ET Calculator?

Definition: This calculator estimates a vehicle's quarter-mile elapsed time (ET) based on its weight and horsepower.

Purpose: It helps automotive enthusiasts and racers predict performance without actual track testing.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ ET = \left(\frac{W}{HP}\right)^{\frac{1}{3}} \times 5.825 \]

Where:

\( ET \) — Quarter-mile elapsed time (seconds)
\( W \) — Vehicle weight (pounds)
\( HP \) — Engine horsepower

Explanation: The formula calculates the theoretical minimum ET based on power-to-weight ratio, with the constant 5.825 derived from empirical data.

3. Importance of ET Calculation

Details: ET estimation helps in vehicle setup, performance tuning, and comparing different configurations.

4. Using the Calculator

Tips: Enter the vehicle's curb weight in pounds and the engine's horsepower. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: It provides a theoretical estimate. Actual ET depends on traction, gearing, aerodynamics, and driver skill.

Q2: Should I use wheel horsepower or crank horsepower?
A: For most accurate results, use wheel horsepower (measured at the wheels).

Q3: Does this include driver weight?
A: No, add driver weight to the vehicle weight for race calculations.

Q4: What's a good quarter-mile time?
A: Street cars typically run 13-15 seconds, while dragsters can run under 7 seconds.

Q5: Can I calculate trap speed too?
A: This calculator only estimates ET. Trap speed requires additional calculations.