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Car Classification

Here is a quick rundown on how to class your car. Classing determines your PAX handicap so you can fairly compete with others. Three over-arching rules apply:

1. Consult the Solo rulebook, which you can download from the SCCA website.
2. If the rules don’t say it is allowed, then it isn’t.
3. If one modification is in a tougher class, your car is in that class.

Motor

  • Intake

    • Aftermarket air filter:Street

    • Cold air intake:Street Touring

    • Aftermarket/modded plenum/intake runners/Throttle body:Street Prepared

  • Exhaust

    • Cat-back exhaust:Street

    • Shorty header:Street Touring

    • Moved/removed catalytic converter, long tube header:Street Prepared

  • Fuel & Ignition

    • Fancy plugs, wires, coils:Street

    • “Chipped”:Street Touring

    • Piggyback computer:Street Touring

    • Upgraded to electronic ignition or coil-on-plug:Street Prepared

    • Standalone computer:Street Prepared

    • Additional carbs, modified carb(s):Street Prepared

  • Engine - Aspiration change

    • Engine swap, same make:Street Modified

    • Added forced induction (turbo, supercharger):Street Modified

    • Forced Induction

    • Bigger downpipe:Street Prepared

    • Boost controllers:Street Prepared

    • Upgraded turbos:Street Modified

    • Aftermarket intercooler:Street Modified/Prepared

    • Supercharger pulley upgrade:Street Modified

    • Upgraded/changed wastegate, blow-off valve:Street Modified

  • Internals

    • Port/polish within 1” of intake/exhaust:Street Prepared

    • Alternate oil pan:Street Touring

    • 0.010 head resurfacing:Street Prepared

    • 0.047 overbore:Street Prepared

    • Further headwork:Prepared

    • Increased compression, replaced internals:Street Modified/Prepared

    • Upgraded cams, valve springs:Prepared

  • Other

    • Underdrive component pulleys, not supercharger:Street Touring

    • Battery Relocation:Street Touring

    • Adjustable cam gears:Street Prepared

    • A/C Removed:Street Prepared

    • Accusump, oil and power steering coolers:Street Prepared

    • Water/meth injection:Street Prepared

    • Torque suppression device (one):Street Prepared

    • Radiator upgrade, in OEM location, dry weight no less than OEM:Street Prepared

    • Electric fan substitution:Street Prepared

    • Removal of emission controls:Street Prepared

Transmission/Driveline

  • OEM LSD:Street

  • Non-OEM LSD:Street Touring only in STX, STU, STR

  • Non OEM clutch:Street Prepared

  • Flywheel lightening:Street Prepared

  • Traction bars:Street Prepared

  • Aftermarket launch control:Street Modified

  • Alternate final drive gears:Prepared

  • Aftermarket axles:Prepared

Wheels/Tires

  • On factory size wheels:Street

  • +1” diameter, ½” depth wheels:Street

  • 140+ treadwear StreetStreet Touring

  • Under 140 treadwear:Street RStreet Prepared

  • Unlimited Wheels:Street Prepared

  • Unlimited DOT tires:Street Prepared

  • Non-DOT tires:Prepared

    • Street Touring wheels and tires:

      • Tires may have section widths up to and including the following:STF, STC, STS, STR (AWD) – 225 mm

      • STX (AWD), STU (AWD) – 245 mm

      • STR (2WD) – 255 mm

      • STX (2WD) – 265 mm

      • STU (2WD) – 285 mm

  • Any wheels are allowed with widths up to the following:STF, STC, STS, STR (AWD) – 7.5”

    • STX (AWD) – 8.0”

    • STX (2WD), STR (2WD) – 9.0”

    • STU – unlimited

Suspension

  • Urethane suspension bushings:Street Touring

  • Aftermarket shocks:Street

  • Aftermarket springs:Street Touring

  • Coilovers:Street Touring

  • Sway bars:one-Street   Both: Street Touring

  • Camber plates:Street Touring

  • A-arms to modify camber setting:Street Touring

Brakes

  • Brake upgrades (rotors, calipers, lines, ducts)Street Touring

Subframes

  • Subframe connectors- longitudinal, not triangulated:Street Touring

  • Strut tower bars:Street Prepared

  • Altered pickup points:Prepared

  • Subframe bushings, all metal:Street Modified

  • Subframe connectors- triangulated and/or cross-frame:Prepared

  • Additional shocks/springs:Modified

Interior

  • Aftermarket gauges:Street

  • Roll bar/cage:Street

  • Shift knob:Street

  • Turbo Timer:Street

  • Harnesses:Street

  • Steering wheel (within one inch diameter change, not oem airbag-equipped):Street

  • Steering wheel replacement- ANY (except airbag-equipped wheels):Street Touring

  • Short shifters:Street Touring

  • Seats, 25lbs+:Street Touring

  • Seats, unlimited weight:Street Prepared

  • Radio Delete:Street Prepared

  • Steering wheel other, and/or airbag deletion:Street Prepared

  • Rear seat removal:Street Modified/Prepared

  • Gutted dashboard, seats, carpet:Prepared

Body

  • Fast and Furious body kit:Street Touring

  • Non OEM spoilers, front and/or rear:Street Prepared

  • Wings (with endcaps and airfoil design):Street Modified/Prepared

  • Sunroof delete:Street Prepared

  • Carbon fiber or fiberglass replacement panels (hood, etc.):Street Modified/Prepared

  • Splitters (limited to rulebook):Street Modified/Prepared

  • Headlight configuration altered:Street Modified/Prepared

  • Gutted/lightened door skins, hood, etc.:Prepared

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