A Drag Time Calculator estimates the elapsed time (ET) required for a vehicle to complete a quarter-mile (1,320 feet) based on its weight and horsepower. This tool is widely used in motorsports, drag racing, and vehicle performance analysis to predict how quickly a car can accelerate over a fixed distance.
By entering key parameters such as the vehicle's total weight and engine horsepower, users can determine the expected quarter-mile time. This calculation is crucial for racers and engineers looking to optimize performance, tuning, and modifications.
Formula of Drag Time Calculator
The formula for estimating quarter-mile elapsed time (ET) is:
Quarter-Mile Time (ET) = 6.290 × (Weight / Horsepower)^0.3547
Where:
- ET: Elapsed time in seconds
- Weight: Vehicle weight in pounds (including driver and fuel)
- Horsepower: Engine power measured at the wheels
This formula provides a reasonably accurate estimation of quarter-mile performance, though actual results may vary based on traction, aerodynamics, and weather conditions.
Precomputed Table for Common Values
| Vehicle Weight (lbs) | Horsepower (HP) | Estimated Quarter-Mile Time (s) |
|---|---|---|
| 2,500 | 300 | 12.08 |
| 3,000 | 400 | 11.18 |
| 3,500 | 450 | 11.56 |
| 4,000 | 500 | 12.02 |
| 4,500 | 600 | 12.24 |
This table provides quick reference values for drag racers and performance enthusiasts.
Example of Drag Time Calculator
Problem: A car weighs 3,200 lbs, including the driver and fuel, and produces 350 horsepower at the wheels. What is its estimated quarter-mile time?
Solution:
Using the formula:
ET = 6.290 × (3,200 / 350)^0.3547
ET = 6.290 × (9.14)^0.3547 ≈ 12.01 seconds
Thus, the estimated quarter-mile time for this vehicle is 12.01 seconds.
Most Common FAQs
This calculator provides a close estimate, but actual quarter-mile times depend on additional factors such as track conditions, weather, tire grip, and aerodynamics.
While primarily designed for drag racing cars, the formula can be applied to motorcycles and other performance vehicles with similar physics.
No, the formula assumes wheel horsepower. If you only have engine horsepower, adjust for drivetrain losses based on transmission type.