1. What is the 1/4 Mile ET Formula?

The 1/4 mile ET (Elapsed Time) formula estimates a vehicle's quarter-mile drag racing time based on its weight and horsepower. This calculation helps racers predict performance and compare different vehicle setups.

2. How Does the Calculator Work?

The calculator uses the 1/4 mile ET formula:

Where:

• \( Weight \) — Vehicle weight in pounds (lbs)
• \( HP \) — Engine horsepower (hp)
• 6.29 — Empirical constant

Explanation: The formula shows that elapsed time is proportional to the cube root of the weight-to-power ratio. Reducing weight or increasing power both improve ET, but with diminishing returns.

3. Importance of ET Calculation

Details: Knowing your estimated ET helps in setting realistic performance goals, comparing different modifications, and understanding how weight and power affect acceleration.

4. Using the Calculator

Tips: Enter vehicle weight in pounds and engine horsepower. For best accuracy, use actual dyno-tested horsepower rather than manufacturer claims.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this formula?
A: It provides a reasonable estimate for rear-wheel-drive vehicles with good traction. Front-wheel-drive or all-wheel-drive vehicles may have different results.

Q2: What's a good 1/4 mile time?
A: Times vary widely: 14-15 seconds is typical for performance cars, under 12 seconds is very fast, and under 10 seconds is professional drag racing territory.

Q3: Does this account for traction or gearing?
A: No, this is a theoretical calculation assuming perfect traction and optimal gearing. Real-world results may differ.

Q4: How much does weight reduction help?
A: Reducing weight by 10% improves ET by about 3%, all else being equal.

Q5: What about turbocharged or supercharged cars?
A: The formula works with the actual horsepower output, regardless of how it's produced.