1. What is a Horsepower ET Calculator?

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

Purpose: It helps automotive enthusiasts and racers predict quarter-mile performance times.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( ET \) — 1/4-mile elapsed time (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 estimate quarter-mile time.

3. Importance of ET Calculation

Details: Quarter-mile time is a standard performance metric in drag racing, helping 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. Actual times vary based on traction, gearing, aerodynamics, and driver skill.

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

Q3: What's considered a good 1/4-mile time?
A: Times vary by vehicle type: 14s are good for sports cars, 12s for performance cars, sub-10s for dedicated drag cars.

Q4: Does this account for forced induction?
A: The formula works for both NA and forced induction if using correct horsepower values.

Q5: Why the cube root in the formula?
A: The cube root relationship accounts for the non-linear relationship between power-to-weight ratio and acceleration.