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Wallace Quarter Mile Equation:
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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 quick and reasonably accurate prediction of drag racing performance.
The calculator uses the Wallace equation:
Where:
Explanation: The equation calculates quarter-mile time based on the power-to-weight ratio, with the cube root relationship reflecting the diminishing returns of additional power.
Details: Quarter-mile time is a standard performance metric in drag racing that helps racers and enthusiasts compare vehicle performance, optimize setups, and predict race outcomes.
Tips: Enter vehicle weight in pounds and engine horsepower. Both values must be positive numbers. The calculator provides estimated quarter-mile elapsed time in seconds.
Q1: How accurate is the Wallace equation?
A: The Wallace equation provides a good estimate for most street-legal vehicles, but actual performance may vary based on traction, gearing, aerodynamics, and driver skill.
Q2: What is considered a good quarter-mile time?
A: Times vary by vehicle type: 14-16 seconds for average sports cars, 12-14 seconds for performance cars, and sub-10 seconds for dedicated drag racing vehicles.
Q3: Does this account for drivetrain loss?
A: The equation typically uses wheel horsepower. If using engine horsepower, results may be slightly optimistic due to drivetrain losses (typically 15-20%).
Q4: Can I use this for motorcycles?
A: Yes, though motorcycle quarter-mile times are often faster than cars with similar power-to-weight ratios due to better power delivery and aerodynamics.
Q5: What factors affect actual quarter-mile times?
A: Traction, launch technique, weather conditions, altitude, tire pressure, and vehicle setup all significantly impact actual performance.