Common questions about SCCA Solo rules, car classing, modifications, and how AutoClass works
Look up your car in Appendix A of the SCCA Solo Rules, which lists specific makes, models, and years with their assigned classes. You can also use AutoClass to search by make, model, and year — it covers all 2,300+ car entries from the 2026 rulebook. If your car isn't specifically listed, it falls under a "Not Otherwise Classified" (NOC) entry for your car's type.
These are progressively less restrictive SCCA Solo categories. Street allows minimal modifications — basically shocks, sway bars, and a few bolt-ons with OE-size tires on similar-size wheels. Street Touring opens up coilovers, intake, exhaust, limited aero, and wider tires. Street Prepared goes further with engine modifications, wider tires, rollbars, and more suspension freedom. Each step up allows more modification but puts you in a more competitive field.
In Street class, allowed modifications include: shock absorbers (must use OE mounting points), one anti-roll bar per axle, alignment changes within factory adjustment range, intake air filter replacement, brake pads and fluid, and a few other minor items. Tires must be 200 treadwear or higher and fit on wheels within one inch of stock diameter. Anything beyond these allowances bumps you to Street Touring or higher.
For local SCCA Solo events, most regions allow non-members to participate by purchasing a weekend membership at the event. For SCCA Solo National Tour events and the Solo National Championship, full SCCA membership is required. Many regions also offer annual memberships that include insurance coverage for all events.
CAM stands for Classic American Muscle. It's a category for American-made performance cars — primarily V8-powered domestics from GM, Ford, and Chrysler/Mopar. CAM has three sub-classes: CAM-T (Traditional, pre-2000 muscle cars), CAM-C (Contemporary, 2000+ domestics), and CAM-S (Sport, two-seaters like Corvettes and Vipers). CAM allows significant modifications including engine work, suspension upgrades, and aftermarket aero within class rules.
Yes, in most cases. Coilover suspension is not allowed in Street class — it will move you to at least Street Touring (if your car has an ST class) or potentially Street Prepared. In Street class, you can only replace shock absorbers while keeping the OE spring type and mounting points. If you already plan to run coilovers, look at the Street Touring or Street Prepared classes for your car.
Appendix A is the section of the SCCA Solo Rules that lists specific car classifications. It contains over 2,300 entries mapping specific makes, models, years, and trims to their assigned classes across Street, Street Touring, and other categories. If your car isn't specifically listed, it falls under a "Not Otherwise Classified" (NOC) catchall for your car type. Appendix A is updated annually when the new rules are published.
NOC stands for "Not Otherwise Classified." In SCCA Solo, each class has NOC entries that serve as catchalls for cars that aren't specifically listed in Appendix A. If your exact car (make, model, year, trim) doesn't appear in the appendix, you fall into the NOC entry for your general vehicle type in the appropriate class. NOC placement is typically determined by vehicle characteristics like weight, engine type, and drivetrain layout.
The SCCA Solo Rules are updated annually. The new rulebook is typically published in the first quarter of each year and takes effect for that competition season. Changes can include new car classifications in Appendix A, modification rule adjustments, and procedural updates. AutoClass is updated each year when the new rules are published — the current version uses the 2026 rulebook.
Yes. AutoClass covers the entire 2026 SCCA Solo rulebook — not just car classification. You can ask about event operations, timing and scoring, course design, protests and appeals, penalties, driver eligibility, safety requirements, or anything else in the rules. Every answer includes citations to the specific section and page number so you can verify in the official rulebook.
Yes, in SCCA Solo you can generally "bump up" to a more permissive category. A car classed in Street can compete in Street Touring, Street Prepared, or higher categories. Within a category, you typically compete in the class where your car is listed. Some specific cross-classing rules apply — for example, certain cars listed in Street Touring can optionally compete in specific Street Prepared classes. Check the current rules for your specific situation.
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