Wallace Racing ET Calculator

Elapsed Time Formula:

\[ ET = \left(\frac{W}{HP}\right)^{\frac{1}{3}} \times 5.825 \]

1/4-mile Elapsed Time (ET): seconds

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1. What is the Wallace Racing ET Calculator?

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

Purpose: It helps drag racing enthusiasts and automotive professionals predict quarter-mile performance.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ ET = \left(\frac{W}{HP}\right)^{\frac{1}{3}} \times 5.825 \]

Where:

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

Explanation: The cube root of the weight-to-power ratio is multiplied by the empirical constant 5.825 to estimate ET.

3. Importance of ET Calculation

Details: Accurate ET prediction helps in vehicle setup, performance tuning, and comparing different configurations.

4. Using the Calculator

Tips: Enter the vehicle weight in pounds and engine horsepower. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this formula?
A: It provides a reasonable estimate for most vehicles, but actual ET depends on traction, gearing, aerodynamics, and other factors.

Q2: Should I use flywheel or wheel horsepower?
A: For most accurate results, use wheel horsepower (measured at the wheels).

Q3: Does this include driver weight?
A: The weight should include the vehicle plus driver and any significant cargo.

Q4: What's a good ET for a street car?
A: Performance varies, but 13-15 seconds is typical for modified street cars, while 12 seconds or below is considered quick.

Q5: Can I calculate horsepower from ET?
A: Yes, the formula can be rearranged to solve for HP if you know the weight and actual ET.