1. What is the Quarter Mile Time Formula?

The quarter mile time formula estimates how long it takes for a street car to complete a quarter mile (1,320 feet) drag race based on its weight and horsepower. This is a standard performance metric in automotive testing.

2. How Does the Calculator Work?

The calculator uses the quarter mile time formula:

Where:

• \( time \) — Quarter mile time in seconds
• \( weight \) — Vehicle weight in pounds
• \( hp \) — Engine horsepower

Explanation: The formula shows that quarter mile time is proportional to the cube root of the weight-to-power ratio. Better power-to-weight ratios result in faster times.

3. Importance of Quarter Mile Time

Details: Quarter mile time is a standard performance metric that allows comparison between different vehicles. It reflects a car's acceleration capability and overall power-to-weight efficiency.

4. Using the Calculator

Tips: Enter vehicle weight in pounds and engine horsepower. Both values must be positive numbers. The calculator provides an estimated quarter mile time in seconds.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this formula?
A: This provides a reasonable estimate for street cars, but actual times may vary based on traction, gearing, driver skill, and other factors.

Q2: What's a good quarter mile time?
A: For production cars, under 14 seconds is considered quick, under 12 is very fast, and under 10 is exceptional (typically modified or high-performance vehicles).

Q3: Does this account for drivetrain loss?
A: No, this uses engine horsepower. For wheel horsepower, you may need to adjust the input value based on your drivetrain type.

Q4: Why the 0.33 exponent?
A: The cube root relationship (0.33 exponent) reflects the non-linear relationship between power-to-weight ratio and acceleration time.

Q5: Can this be used for motorcycles?
A: While the basic physics applies, motorcycles may have different coefficients due to their different weight distribution and aerodynamics.