1. What is Horsepower from Quarter-Mile Elapsed Time?

This calculator estimates engine horsepower based on vehicle weight and quarter-mile elapsed time (ET). It provides a practical method for evaluating vehicle performance without requiring specialized dynamometer equipment.

2. How Does the Calculator Work?

The calculator uses the horsepower formula:

Where:

• \( Weight \) — Vehicle weight in pounds (lbs)
• \( ET \) — Quarter-mile elapsed time in seconds
• \( 234 \) — Empirical constant derived from performance data

Explanation: The formula relates horsepower to the cube of elapsed time, reflecting the non-linear relationship between power and acceleration performance.

3. Importance of HP Calculation

Details: Accurate horsepower estimation is crucial for performance tuning, vehicle comparisons, and understanding the relationship between power, weight, and acceleration.

4. Using the Calculator

Tips: Enter vehicle weight in pounds and quarter-mile elapsed time in seconds. Use consistent units and ensure values are realistic (ET typically 10-20 seconds for street vehicles).

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: This provides a good estimate but may vary due to traction, aerodynamics, transmission efficiency, and other factors affecting real-world performance.

Q2: What is considered good quarter-mile time?
A: For street cars, 12-14 seconds is good performance. Professional drag cars can achieve times under 6 seconds.

Q3: Should I use curb weight or race weight?
A: Use the actual weight during the run (race weight) including driver and fuel for most accurate results.

Q4: Does this account for drivetrain loss?
A: This calculates wheel horsepower. To estimate engine horsepower, add approximately 15-20% for typical drivetrain losses.

Q5: Can I use this for motorcycles?
A: Yes, the formula works for any vehicle as long as weight and ET are accurately measured.