1. What is the Wallace ET Equation?

The Wallace ET (Elapsed Time) equation estimates quarter-mile race time based on vehicle weight and horsepower. It provides a theoretical prediction of drag racing performance under ideal conditions.

2. How Does the Calculator Work?

The calculator uses the Wallace equation:

Where:

• \( WT \) — Vehicle weight (pounds)
• \( HP \) — Engine horsepower

Explanation: The equation calculates the cube root of the weight-to-power ratio and multiplies it by the constant 5.825 to estimate quarter-mile elapsed time.

3. Importance of ET Calculation

Details: ET estimation is crucial for drag racing enthusiasts to predict vehicle performance, compare different setups, and optimize weight-to-power ratios for better track times.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: How accurate is the Wallace ET equation?
A: The equation provides a theoretical estimate. Actual track times may vary due to traction, aerodynamics, driver skill, and track conditions.

Q2: Does this account for drivetrain loss?
A: No, the equation uses raw horsepower numbers. For more accurate estimates, use wheel horsepower instead of engine horsepower.

Q3: What is a good ET for a street car?
A: Most production cars range from 13-16 seconds. Performance models can achieve 11-13 seconds, while dedicated drag cars can run under 10 seconds.

Q4: How does weight reduction affect ET?
A: Reducing weight has a similar effect to increasing horsepower. A 10% weight reduction is roughly equivalent to a 10% power increase in terms of ET improvement.

Q5: Can this calculator predict trap speed?
A: No, this equation only estimates elapsed time. Different equations are needed to calculate trap speed.