1. What is a Horsepower to ET Calculator?

Definition: This calculator estimates 1/8-mile elapsed time (ET) based on vehicle 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:

Where:

• \( ET \) — Elapsed time (seconds)
• \( W \) — Vehicle weight (pounds)
• \( HP \) — Engine horsepower

Explanation: The formula approximates the relationship between power-to-weight ratio and acceleration performance.

3. Importance of ET Calculation

Details: Knowing estimated ET helps in vehicle setup, performance tuning, and predicting race outcomes.

4. Using the Calculator

Tips: Enter vehicle weight in pounds and engine horsepower. All values must be > 0. The result is an estimate - actual performance may vary based on traction, gearing, and other factors.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: It provides a reasonable estimate but doesn't account for traction, gearing, or aerodynamics. Real-world times may vary by ±0.5 seconds.

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

Q3: Does this include driver weight?
A: The weight should include the vehicle plus driver and any significant cargo - total racing weight.

Q4: Can I calculate 1/4-mile ET from this?
A: Multiply the 1/8-mile ET by approximately 1.55 to estimate 1/4-mile time.

Q5: What's a good 1/8-mile ET?
A: For street cars, 8-10 seconds is typical. Performance cars run 6-8 seconds, while dedicated dragsters can be under 5 seconds.