Home
Back
Wallace Quarter-mile Equation:
| From: | To: |
The Wallace Quarter-mile Equation estimates the elapsed time (ET) for a vehicle to complete a quarter-mile drag race based on weight and horsepower. It provides a theoretical performance benchmark for automotive enthusiasts and racers.
The calculator uses the Wallace equation:
Where:
Explanation: The equation demonstrates the cubic relationship between power-to-weight ratio and quarter-mile performance, showing how small changes in either parameter can significantly affect race times.
Details: Quarter-mile time is a standard performance metric in automotive racing that helps enthusiasts compare vehicle performance, plan modifications, and set realistic performance expectations.
Tips: Enter vehicle weight in pounds and horsepower. Use curb weight for most accurate results. All values must be valid (weight > 0, HP > 0).
Q1: How accurate is the Wallace equation?
A: The Wallace equation provides a good theoretical estimate but actual performance may vary due to traction, aerodynamics, driver skill, and transmission efficiency.
Q2: What is considered a good quarter-mile time?
A: Times vary by vehicle type: 14+ seconds for average cars, 12-13 seconds for performance cars, 10-11 seconds for sports cars, and under 10 seconds for dedicated race vehicles.
Q3: Should I use curb weight or gross weight?
A: For most accurate theoretical calculations, use curb weight (vehicle weight without passengers or cargo). For real-world planning, include driver and fuel weight.
Q4: What factors affect quarter-mile time besides weight and HP?
A: Traction, aerodynamics, transmission type, tire compound, launch technique, and weather conditions all significantly impact actual quarter-mile performance.
Q5: Can this calculator predict trap speed?
A: No, this calculator only estimates elapsed time. Trap speed calculations require additional variables and different formulas.