1. What is a Horsepower to ET Calculator?

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

Purpose: It helps automotive enthusiasts and racers predict quarter-mile performance times without actual track testing.

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 theoretical minimum ET based on power-to-weight ratio, with the cube root relationship showing how ET improves disproportionately as power increases.

3. Importance of 1/4 Mile Time Calculation

Details: Quarter-mile time is a standard performance metric that helps compare vehicle acceleration capabilities and predict drag racing outcomes.

4. Using the Calculator

Tips: Enter the vehicle's curb weight (including driver) in pounds and the engine's horsepower. For more accurate results, use wheel horsepower if known.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculator?
A: It provides theoretical best-case times. Real-world times will be slower due to traction limits, drivetrain losses, and other factors.

Q2: Should I use crank HP or wheel HP?
A: Wheel horsepower (measured at the wheels) gives more accurate results as it accounts for drivetrain losses.

Q3: Why the cube root relationship?
A: Acceleration depends on power-to-weight ratio, but ET improves disproportionately as power increases because higher power allows maintaining acceleration longer.

Q4: What's a good 1/4 mile time?
A: Times vary by vehicle type: 14s for sporty cars, 12s for performance cars, 10s for dedicated drag cars, and sub-10s for purpose-built race cars.

Q5: Does this account for traction or gearing?
A: No, this is a theoretical calculation assuming perfect traction and optimal gearing. Real-world results may vary.