SCCA PAX Calculator

How to Use the SCCA PAX Calculator

The SCCA PAX Calculator is a valuable tool used to calculate a participant's PAX time in autocross events. Autocross is a competitive motorsport where drivers navigate through a defined course, aiming to achieve the fastest time. PAX time is a handicap time that allows vehicles of different classes to compete fairly against each other. By utilizing the SCCA PAX Calculator, participants can determine their adjusted time, enabling them to compare their performance with drivers from various vehicle classes.

The primary application of the SCCA PAX Calculator is for individuals participating in autocross events. It helps level the playing field and promotes fair competition among drivers by factoring in the performance characteristics of different vehicles.

Instructions for Utilizing the Calculator

To effectively use the SCCA PAX Calculator, follow these steps:

• Vehicle Make: Enter the make or manufacturer of your vehicle.
• Vehicle Model: Specify the model of your vehicle.
• Vehicle Class: Select the appropriate vehicle class from the provided options.
• Run Time: Enter the time it took you to complete the autocross course in seconds.
• Tire Width: Input the width of your vehicle's tires in millimeters.
• Tire Aspect Ratio: Provide the aspect ratio of your vehicle's tires.
• Wheel Diameter: Enter the diameter of your vehicle's wheels in inches.

After entering all the required information, click the "Calculate PAX time" button.

The output fields of the SCCA PAX Calculator are as follows:

• Vehicle Make: Displays the vehicle make entered by the user.
• Vehicle Model: Displays the vehicle model entered by the user.
• Vehicle Class: Shows the selected vehicle class.
• Run Time: Displays the time entered by the user.
• Tire Width: Displays the tire width entered by the user.
• Tire Aspect Ratio: Displays the tire aspect ratio entered by the user.
• Wheel Diameter: Displays the wheel diameter entered by the user.
• PAX Time: Provides the calculated PAX time based on the input values.

SCCA PAX Calculator Formula

The SCCA PAX Calculator uses a formula developed by the Sports Car Club of America (SCCA) to calculate the PAX time. The formula takes into account various factors, including tire width, tire aspect ratio, wheel diameter, and the run time.

PAX Time = Run Time * (0.9909 - 0.0005 * Tire Width + 0.004 * Tire Aspect Ratio + 0.201 * ln(Wheel Diameter))

Illustrative Example

Let's consider an example to better understand how to use the SCCA PAX Calculator. Suppose a participant driving a vehicle with a tire width of 225mm, a tire aspect ratio of 45, and a wheel diameter of 17 inches completes the autocross course in 60 seconds. Using the calculator, the PAX time can be calculated as follows:

• PAX Time = 60 seconds * (0.9909 - 0.0005 * 225 + 0.004 * 45 + 0.201 * ln(17))
• PAX Time ≈ 51.832 seconds

In this example, the participant's PAX time is approximately 51.832 seconds.

Illustrative Table Example

Here is an example table showcasing multiple sets of input data and the corresponding PAX times calculated using the SCCA PAX Calculator:

The SCCA PAX Calculator is an invaluable tool for autocross participants looking to compare their performance across different vehicle classes. By providing essential information such as vehicle make, model, class, run time, tire width, tire aspect ratio, and wheel diameter, participants can determine their PAX time. The calculated PAX time allows for fair competition and provides a standardized benchmark to evaluate performance irrespective of the vehicle's class.

Utilizing the SCCA PAX Calculator helps autocross enthusiasts gauge their progress, identify areas for improvement, and foster healthy competition. It facilitates a more inclusive and balanced environment by accounting for the varying characteristics of different vehicles. Whether you're a seasoned autocross competitor or a beginner, the SCCA PAX Calculator is an indispensable tool to enhance your autocross experience and track your performance accurately.