1/4 Mile HP to Weight ET Calculator

ET Formula:

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

1/4 Mile ET (seconds):

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1. What is a 1/4 Mile HP to Weight ET Calculator?

Definition: This calculator estimates a vehicle's 1/4 mile elapsed time (ET) based on its weight and horsepower.

Purpose: It helps automotive enthusiasts and racers predict quarter-mile performance from basic vehicle specifications.

2. How Does the Calculator Work?

The calculator uses the formula:

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

Where:

\( ET \) — Elapsed time for 1/4 mile (seconds)
\( W \) — Vehicle weight (pounds)
\( HP \) — Engine horsepower

Explanation: The formula calculates the cube root of the weight-to-power ratio and scales it to approximate real-world ET.

3. Importance of ET Calculation

Details: Quarter-mile time is a standard performance metric that helps compare vehicle acceleration capabilities.

4. Using the Calculator

Tips: Enter the vehicle's curb weight (including driver) in pounds and the engine's horsepower. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: It provides a theoretical estimate. Real-world 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 account for forced induction?
A: The formula works for both NA and forced induction, as long as you input the correct horsepower figure.

Q4: What's a good 1/4 mile time?
A: Street cars typically range 12-15 seconds. Performance cars 10-12s. Dragsters can be under 7s.

Q5: Can I calculate horsepower from ET and weight?
A: Yes, by rearranging the formula: \( HP = W / (ET / 5.825)^3 \)