Rallycross classes work much differently from autocross. Cars are grouped in classes based on drivetrain — FWD, RWD, or AWD. Vehicles are grouped into competition categories with other cars with similar performance levels and modifications.
- Stock: Cars in this class must be very close to how the car rolled off the showroom floor. Only DOT-approved street tires such as all-season or snow tires are allowed, and you could add mud flaps and skid plates if you like.
- Prepared: This class allows for limited suspension and bolt-on power upgrades. Stage rally tires are also allowed, and one limited slip differential can be modified.
- Modified: This class allows for all kinds of modifications including engine swaps, gutted interiors, etc.
Once grouped by drivetrain and classed by the categories listed above, it’s easy to find your class abbreviation. Simply take the first letter of the category and the drivetrain type, and that’s your class. Examples:
- A stock FWD car would be “SF”
- A modified AWD car would be “MA”
For full classing details, check out the full SCCA Rallycross Rulebook. If you’re looking to class your car, you’ll find that information in Section 6 of that PDF. It also includes safety rules.
If you have any questions, don’t forget that you can always ask an event official beforehand and they can help to steer you in the right direction.