1. What is the 1/4 Mile ET Equation?

The 1/4 Mile ET (Elapsed Time) equation estimates a vehicle's quarter-mile drag racing time based on its weight and horsepower. This empirical formula provides a quick estimation of performance potential.

2. How Does the Calculator Work?

The calculator uses the 1/4 Mile ET equation:

Where:

• \( Weight \) — Vehicle weight in pounds (lbs)
• \( HP \) — Engine horsepower (hp)
• 6.29 — Empirical constant

Explanation: The equation shows that elapsed time is proportional to the cube root of the weight-to-power ratio. This reflects the non-linear relationship between power and acceleration.

3. Importance of ET Calculation

Details: Quarter-mile time is a standard performance metric in drag racing. While actual performance depends on many factors (traction, aerodynamics, gearing), this calculation provides a useful baseline for comparing vehicles.

4. Using the Calculator

Tips: Enter vehicle weight in pounds and engine horsepower. Both values must be positive numbers. The result is an estimated quarter-mile elapsed time in seconds.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: This provides a rough estimate. Actual performance may vary by ±0.5 seconds depending on traction, aerodynamics, and drivetrain efficiency.

Q2: Does this account for driver skill?
A: No, this is a theoretical calculation based solely on weight and power. Driver reaction time and shifting skill aren't considered.

Q3: Should I use wheel horsepower or engine horsepower?
A: For most accurate results, use wheel horsepower (measured at the wheels) as this accounts for drivetrain losses.

Q4: What's a good quarter-mile time?
A: Street cars typically run 12-15 seconds. Performance cars run 10-12 seconds. Professional drag cars can run under 7 seconds.

Q5: Can I calculate trap speed too?
A: This calculator only estimates ET. Trap speed would require a separate calculation considering additional factors.