1. What is an ET and MPH Calculator?

Definition: This calculator estimates a vehicle's quarter-mile elapsed time (ET) and trap speed (MPH) based on weight and horsepower.

Purpose: It helps automotive enthusiasts and racers predict performance without actual track testing.

2. How Does the Calculator Work?

The calculator uses two formulas:

Where:

• \( ET \) — Elapsed time for 1/4 mile (seconds)
• \( MPH \) — Speed at finish line (miles per hour)
• \( W \) — Vehicle weight (pounds)
• \( HP \) — Engine horsepower

Explanation: The formulas account for the cubic relationship between power-to-weight ratio and performance.

3. Importance of Performance Calculation

Details: Accurate predictions help in vehicle setup, tuning decisions, and competition planning.

4. Using the Calculator

Tips: Enter vehicle weight (including driver) in pounds and engine horsepower. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How accurate are these estimates?
A: They provide reasonable approximations for stock to mildly modified vehicles. Highly modified or traction-limited vehicles may vary.

Q2: Does this include drivetrain loss?
A: The formulas assume rear-wheel horsepower. For crank HP, multiply by ~0.85 for RWD, ~0.80 for FWD/AWD.

Q3: What affects real-world results?
A: Traction, aerodynamics, shift points, and weather conditions can significantly impact actual performance.

Q4: Can I use this for motorcycles?
A: Yes, though two-wheeled vehicles may show different results due to weight distribution and aerodynamics.

Q5: Why the cube root relationship?
A: Performance scales with the cube root of power-to-weight ratio due to acceleration physics.