Philosophy of the GGR Points System

The Pre-2006 Recipe-Based Rules System

Prior to 2006, GGR car classification was based upon placing similar-model cars into a class (e.g. 930's into class M), with subclasses based upon which of an allowed set of modifications had been made to the car (e.g. a strut bar placed the car into the "Improved" class Mi). Over the years a number of factors caused this "recipe-based" classification system to be reconsidered.

First, there were often too few competitors in each class for interesting competition. The average class had fewer than 1.5 participants at each event.

Second, the recipe approach where only specific modifications were allowed at each competition level unnecessarily punished those who had not built their cars specifically for GGR competition. A modification as simple as changing from 16" to 17" wheels could move a car from a stock class into one where it ran against full race prepared cars where it was clearly uncompetitive.

Third, during the term of the recipe-based system, there was a proliferation of new Porsche models. Since the classes were model-based, this in itself resulted in many more classes for the same number of competitors. Just as bad, new cars had performance features that the existing rules were not designed to accommodate, making modified classes inappropriate.

The Points-Based Classification System

Rather than a model-based system with specific recipies for modified classes, the new GGR classification system, specified in the GGR Rule Book, is based upon points. Each distinct car model (by specific model and year) has a base point assignment. Each performance-enhancing modification to a base car adds additional points. For example, changing to a non-stock performance muffler adds 5 points while going to headers adds an additional 10 points. Adjustable shocks adds another 10 points, etc. Wider wheel widths, race tires, and engine displacement increases all add points. A car's base points plus all modification points determines its class.

Cars with similar point totals compete with each other in class. For instance, in Time Trials, cars with between 401 and 450 points are class TT12 while cars with between 451 and 500 points are in TT11. Autocross classes have slightly different points totals, for example, 451-500 points is AX12

In Time Trials, highly modified cars over a designated modification point threshold (650) are assigned to the appropriate GT class according to PCA Club Racing rules. GT cars are classified primarily according to displacement, and are required to have specific safety equipment.

The GGR Classification Web Site

Recognizing that computing car classes manually is tedious and error-prone, GGR has provided this web site to make classifying cars as simple and accurate as possible. Moreover, since the site is public, it acts as a peer review mechanism that allows all participants to see what modifications their competitors are using.

As a service to other PCA regions that use GGR rules, members of those regions are welcomed and encouraged to use this web site to classify their cars.


For questions or to report problems contact the Site Administrator