Car Classes

Car Classifications:

Stock- your basic showroom vehicle. Additional modifications permitted by SCCA:
R (race) compound DOT tires (e.g. Hoosiers, Kumho's are popular)
factory wheels or aftermarket wheels of the same size/width/offset +/- 1/4"
any shock using the original mounting points or of a similar style or type (no coilovers)
any muffler, exhaust or tip from the catalytic converter back.
any FRONT sway bar.
additional "comfort and convenience" items that do not materially impact vehicle performance.

STS-Street tire class for 4 seat compacts, aka "tuners" which have been lightly tuned:

Aftermarket shock/springs, including lowering springs and adjustable shocks/struts

Camber kits, urethane bushings, any swaybars, strut tower braces permitted

Maximum wheel width of 7.5", up to 225mm tires, tradwear rating minimum of 140

(popular tires include Falken Azenis and Kumho MX)

Cold air intakes and short tube headers are legal, but no throttle body modifications permitted.

Reflashed ECUs permitted, but no standalone/piggyback units. Aftermarket Ignition wires/plugs OK.

Aftermarket brake rotors and pads permitted, but stock calipers/drums must remain.

Stickers, subwoofers, aftermarket (padded reclining) seats, Altezzas, vertical doors permitted.

NOTE: Carbon fiber hoods, enormous wings, and weight reductions will put you in Street Mod. Nitrous is not permitted

at autocross events, so save it for the drag strip.

Underdrive pulleys and battery relocations permitted.

STX- Street tire class for cars with engines up to 5 liters NA or 2 liters turbo.

Same rules apply as STS, but up to 8" wheels and 245 mm tires.

Limited slips allowed for 2WD cars.

STU- Street tire class for larger NA motors, or up to 3.1 liters turbo/supercharged

Unrestricted wheel width,

Tire width up to 275 (RWD) or 245 (AWD).

Street Prepared- Cars with aftermarket components that are strictly bolt on. Internal mods are limited. Everthing

that is allowed above PLUS:
Coilovers permitted
DOT tires, R compounds are encouraged.
Limited slip differentials can be added
any bolt on engine components (non-internal in other words), including headers, carbs, bigger injectors, fuel injection mods,

computers, throttle bodies, ITBs, port-matched/decked heads.

Wheels are open, -1, +1,+2 and +3 are allowed, and as wide as you can get without rubbing.

Moving on to the serious track hound...

Prepared- the next modification stage. Internal engine mods, radical suspensions, stripped interiors etc. Modifications allowed include:

Racing Slicks/Non DOT racing tires permitted
weight minimums are based on engine displacement.
wheel size is dependent on engine and class.
Mondo Bizarro suspensions, subframe connectors, chassis braces.
Any brakes permitted, ducting, etc.

Chassis reinforcement and stiffening permitted (welded or bolt on), Holes/notching permitted to allow these mods.
Engines with internal modifications permitted. Larger displacement may add a weight penalties.
Roll cages may be required, a must for convertibles.
Transmissions, close ratio gears, strange rear axle ratios are expected
Racing fuel tank permitted

Glass can be replaced with Lexan or removed entirely.
Light weight body panels i.e fiberglass and carbon fiber are acceptable, lighting (i.e. headlights) may be removed.

Any seat permitted, interior/doors may be gutted. Factory hinges may be removed, but doors must open.
Check the rule book if you think you are in the Prepared Class. There is a lot to cover.

Street Mod- allows about anything that started life as a production car.

Better show up with slicks, wide ones!

Turbos, larger Turbos, Superchargers.

Engine swaps from the same manufacturer.

NA goodies such as wild cams, high compression internals, strokers, oversized valves.

Street Mod 2- Street mod class for 2 seaters

Modified - the highest level of preparation allowed - usually devoted to purpose built race cars, like Formula Fords or production based cars with engine transplants.

A Modified car, with few exceptions, was never meant to be street legal. No weight restrictions, as much bracing,

carbon fiber/fiberglass as possible, probably one seat, roll cage, no battery, etc. Must be trailered to events. If you are in

the Modified class, you are not looking here to see what it is.

SSCC Classes
Novice - All newcomers, limited to 7 events in the past year. If you autocrossed in another region, those runs count towards your seven.

Open - This class is used to provide a place for experienced drivers or those that have exceeded the 7 event limit in Novice Class.

Street Tire - For people who don't want to spend money on extra wheels and race tires. Please note that STS rules allow mods that would create an unfair advantage against otherwise normally stock indexed cars. For that reason we give them a home of their own in the open groups.

PAX - For the Nationally competitive types.

Ladies PAX - Our own Girl Power class.