1. What is a Quarter Mile HP Calculator?

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

Purpose: It helps automotive enthusiasts and professionals estimate engine power without dyno testing.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HP \) — Estimated horsepower
• \( W \) — Vehicle weight (pounds)
• \( ET \) — 1/4-mile elapsed time (seconds)

Explanation: The formula relates power-to-weight ratio to acceleration time over a standard distance.

3. Importance of HP Calculation

Details: Accurate HP estimation helps in vehicle tuning, performance comparison, and verifying manufacturer claims.

4. Using the Calculator

Tips: Enter the vehicle weight in pounds (including driver) and the 1/4-mile elapsed time in seconds. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: It provides a reasonable estimate but actual HP may vary due to traction, aerodynamics, and drivetrain losses.

Q2: What's the 5.825 constant in the formula?
A: This empirical constant relates ET to power-to-weight ratio based on drag racing data.

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

Q4: Does this work for all vehicle types?
A: It works best for rear-wheel drive vehicles. FWD/AWD may show different results due to traction differences.

Q5: How can I improve accuracy?
A: Use multiple runs' average ET and exact race weight. Consider dyno testing for precise measurement.