1. What is a 1/4-Mile 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 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 approximates the relationship between power-to-weight ratio and acceleration performance.

3. Importance of 1/4-Mile 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 calculator?
A: It provides a theoretical estimate. Actual times vary based on traction, gearing, aerodynamics, and driver skill.

Q2: Should I use wheel horsepower or crank horsepower?
A: For most accuracy, use wheel horsepower (measured at the wheels). Crank HP will give optimistic results.

Q3: Does this account for drivetrain losses?
A: No, the formula assumes perfect traction and no drivetrain losses. Subtract 10-15% from crank HP for RWD vehicles.

Q4: What's a good 1/4-mile time?
A: Street cars typically run 13-16 seconds. Performance cars 10-13s. Race cars can be under 10s.

Q5: Can I calculate trap speed with this?
A: No, this only estimates elapsed time. Trap speed requires additional calculations.