1/4 Mile ET HP Calculator

Quarter-Mile ET Equation:

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

Estimated Quarter-Mile Time (ET):

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1. What is the Quarter-Mile ET Equation?

The Quarter-Mile ET (Elapsed Time) equation estimates the time it takes for a vehicle to complete a quarter-mile drag race based on its weight and horsepower. This calculation provides a theoretical performance benchmark for automotive enthusiasts and racers.

2. How Does the Calculator Work?

The calculator uses the Quarter-Mile ET equation:

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

Where:

\( ET \) — Quarter-mile elapsed time (seconds)
\( weight \) — Vehicle weight (pounds)
\( HP \) — Engine horsepower
\( 5.825 \) — Empirical constant

Explanation: The equation demonstrates the cubic relationship between power-to-weight ratio and acceleration performance, where small changes in power or weight can significantly affect quarter-mile times.

3. Importance of Quarter-Mile Time Calculation

Details: Quarter-mile time is a standard performance metric in automotive racing that helps enthusiasts compare vehicle acceleration capabilities, plan modifications, and set performance goals.

4. Using the Calculator

Tips: Enter vehicle weight in pounds and engine horsepower. Use curb weight for most accurate results. All values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: This provides a theoretical estimate. Actual performance depends on traction, transmission, aerodynamics, driver skill, and environmental conditions.

Q2: What is considered a good quarter-mile time?
A: Times vary by vehicle type: 14-16 seconds for sport compacts, 12-14 seconds for sports cars, 10-12 seconds for supercars, and under 10 seconds for dedicated drag vehicles.

Q3: Should I use curb weight or gross weight?
A: For most accurate performance estimates, use curb weight (vehicle weight with fluids but without passengers or cargo).

Q4: Does this account for drivetrain loss?
A: This calculation uses engine horsepower. For wheel horsepower, multiply by approximately 1.15 for rear-wheel drive or 1.20 for front-wheel drive vehicles.

Q5: Can I use this for electric vehicles?
A: Yes, but electric vehicles often achieve better actual times due to instant torque delivery and different power curves compared to internal combustion engines.