bgriggs
01-19-2009, 10:45 AM
Stock
This category includes mass-produced, common vehicles that may be
“daily drivers” (cars used for normal, everyday driving). Stock Category cars
compete in their “factory” configuration with a minimal number of allowances (not
requirements) such as:
Removal of spare tire and tools
Front anti-roll bar(s)
Suspension/wheel alignment using standard adjustments
High-performance DOT tires (including competition R-compounds)
Shock absorbers/struts (2 external adjustments maximum)
Competition-type seat belts (no shoulder belts in open cars)
Brake linings (pads/shoes)
Air filter element (the “throw-away” part)
“Cat”-back exhaust systems
Wheels of standard size (diameter, width, and offset within ¼”)
Roll bar/cage
Gauges, indicator lights, etc.
Please refer to the SCCA® National Solo® Rules for more details and specifics.
Street Touring®
Started in 1997, this is one of the more popular categories
which includes Street Touring® Sport (STS), Street Touring® Sport 2-seater
(STS2), Street Touring® Xtra (STX), and Street Touring® Ultra (STU). This is the
only category that does not allow competition R-compound tires – only high
performance tires with a UTQG treadwear rating of 140 or higher.
STS
Consists of sedans/coupes with four seats minimum and normally aspirated
engines up to 3.1L (very few turbo/supercharged cars are allowed).
Stock category allowances
No limited slip differentials except for standard viscous-types
Pedal kits and other interior trim
Front seats (15 pounds minimum weight each)
Rub strips, emblems, and mud flaps removed
Body kits, spoilers, and wings added
Tires up to 225 mm wide, UTQG treadwear 140 minimum
Wheels up to 7½ inches wide, any diameter/offset
Shocks/struts
Drilled/slotted rotors (standard size) and braided DOT brake lines
Anti-roll bars, front and rear
Lowered suspensions using standard-type springs
Suspension bushings (non-metallic)
Camber kits, plates, or bolts
Traction bars, torque arms, panhard rods
Strut bars, 2-point only
Battery relocated
Air filter systems up to throttle body or compressor inlet
Headers, emissions compliant
Engine computers (PCM/ECU) reprogrammed
Shifter kits
Accessory drive pulleys
Motor mounts (non-metallic)
Example of included cars: Audi A4 1.8T and TT (non-quattro), Mazda 323 GT
and GTX (AWD), Volkswagen Golf/GTi/Jetta/Beetle/Passat 1.8T and TDI,
Volvo S40 (except T5) and V40
Example of excluded cars: Datsun Z 2+2, Honda CRX, MGB GT, Porsche
(all), Triumph (all)
STS2
is for sports cars with 2 seats and normally aspirated engines up to 1.9L.
STS allowances
Included cars: BMW Z3, Honda CRX and del Sol, Mazda Miata (1990-97) and
RX-7 (1979-92) (non-turbo), Toyota MR2 (1985-89) (non-supercharged)
Excluded cars: Lotus (all), Mazda Miata (1999+), Toyota MR2 (1991-95,
2000+)
STX
is for sedans/coupes with four seats and engines up to 5.1L normally-
aspirated or up to 2.0L turbo/supercharged.
STS allowances
Tires up to 245 mm wide, UTQG treadwear 140 minimum
Wheels up to 8 inches wide, any diameter/offset
Limited slip differentials allowed (including aftermarket) for 2WD cars
High-flow “cat”
Larger brake calipers and rotors
Excluded cars: Audi S4 (V8 engine), BMW M3 (E36, E46) and M5, Mitsubishi
Lancer Evolution, Subaru Impreza WRX STi, Mazda RX-8
STU
is for sedans/coupes with four seats and normally aspirated engines of any
displacement normally aspirated or turbo/supercharged engines up to 3.1L.
STS and STX allowances
No wheel restrictions
Tires for 2WD cars up to 275 mm wide (245 for AWD)
Example of included cars: Audi S4, BMW M3 (E36), Chevrolet Camaro, Dodge
SRT-4, Ford Mustang, Mazda RX-8, Mitsubishi Lancer Evolution, Pontiac
Firebird / Trans Am and GTO, Subaru Impreza WRX STi, Volvo S60 R,
Toyota Supra
Excluded cars: BMW M3 (E46) and M5 (E39)
Refer to the SCCA® National Solo® Rules for full details and specifications on
the Street Touring® allowances.
Street Prepared
The original SCCA® “street” category, Street Prepared allows
any carburetor/fuel injection system and any ignition system. Turbo/supercharger
hardware has to remain standard, but aftermarket boost control
systems/programs and intercoolers are allowed. Exhaust manifolds and systems
are free. Emission controls are not required for competition, but no internal
engine or transmission modifications are allowed beyond factory specs (no cams,
hi-comp pistons, ported heads, etc). Some cars are able to update/backdate
components like engines, brakes, etc (See Solo Rules for details and specifics).
There are no limits on wheels sizes or DOT tires; racing springs and shocks are
the norm.
Street Modified
The top of the “street” categories, Street Modified allows
anything from Stock, Street Touring, and Street Prepared and just about any
engine and drivetrain configuration as long as the engine manufacturer matches
the body manufacturer (see Solo Rules for details). Four-seaters (BMW, Corolla,
Civic, Integra, Neon, Supra, Talon, VW, etc.) run in SM and two-seat sports cars
(Corvette, CRX, M Roadster, Miata, RX-7, MR2, etc.) compete in SM2. Carbon-
fiber hoods, cams, turbo/supercharger kits, etc are welcome, too.
Prepared
These cars are not for the street; they are virtually race-prepared
vehicles for dedicated Solo® competition. Gutted interiors and racing slicks are
the first visual characteristics of these cars and when they crank up, you can tell
these engines weren’t built for bringing home the groceries. Convertible cars are
required to install roll bars per the Solo Rules.
Modified
Except for D and E Modified, these were never ever “street” cars.
They are special built competition vehicles and most of them resemble an open-
wheel Indy car or a closed-wheel LeMans sports racer. DM and EM cars may
have started life on the streets, but just about any engine, drivetrain, or
suspension is permitted. Supercharged rotary engines and V-8 engines are seen
in 1700-pound EM machines and powerful 4-cylinders are common in 1300-
pound DM lightweights.
This category includes mass-produced, common vehicles that may be
“daily drivers” (cars used for normal, everyday driving). Stock Category cars
compete in their “factory” configuration with a minimal number of allowances (not
requirements) such as:
Removal of spare tire and tools
Front anti-roll bar(s)
Suspension/wheel alignment using standard adjustments
High-performance DOT tires (including competition R-compounds)
Shock absorbers/struts (2 external adjustments maximum)
Competition-type seat belts (no shoulder belts in open cars)
Brake linings (pads/shoes)
Air filter element (the “throw-away” part)
“Cat”-back exhaust systems
Wheels of standard size (diameter, width, and offset within ¼”)
Roll bar/cage
Gauges, indicator lights, etc.
Please refer to the SCCA® National Solo® Rules for more details and specifics.
Street Touring®
Started in 1997, this is one of the more popular categories
which includes Street Touring® Sport (STS), Street Touring® Sport 2-seater
(STS2), Street Touring® Xtra (STX), and Street Touring® Ultra (STU). This is the
only category that does not allow competition R-compound tires – only high
performance tires with a UTQG treadwear rating of 140 or higher.
STS
Consists of sedans/coupes with four seats minimum and normally aspirated
engines up to 3.1L (very few turbo/supercharged cars are allowed).
Stock category allowances
No limited slip differentials except for standard viscous-types
Pedal kits and other interior trim
Front seats (15 pounds minimum weight each)
Rub strips, emblems, and mud flaps removed
Body kits, spoilers, and wings added
Tires up to 225 mm wide, UTQG treadwear 140 minimum
Wheels up to 7½ inches wide, any diameter/offset
Shocks/struts
Drilled/slotted rotors (standard size) and braided DOT brake lines
Anti-roll bars, front and rear
Lowered suspensions using standard-type springs
Suspension bushings (non-metallic)
Camber kits, plates, or bolts
Traction bars, torque arms, panhard rods
Strut bars, 2-point only
Battery relocated
Air filter systems up to throttle body or compressor inlet
Headers, emissions compliant
Engine computers (PCM/ECU) reprogrammed
Shifter kits
Accessory drive pulleys
Motor mounts (non-metallic)
Example of included cars: Audi A4 1.8T and TT (non-quattro), Mazda 323 GT
and GTX (AWD), Volkswagen Golf/GTi/Jetta/Beetle/Passat 1.8T and TDI,
Volvo S40 (except T5) and V40
Example of excluded cars: Datsun Z 2+2, Honda CRX, MGB GT, Porsche
(all), Triumph (all)
STS2
is for sports cars with 2 seats and normally aspirated engines up to 1.9L.
STS allowances
Included cars: BMW Z3, Honda CRX and del Sol, Mazda Miata (1990-97) and
RX-7 (1979-92) (non-turbo), Toyota MR2 (1985-89) (non-supercharged)
Excluded cars: Lotus (all), Mazda Miata (1999+), Toyota MR2 (1991-95,
2000+)
STX
is for sedans/coupes with four seats and engines up to 5.1L normally-
aspirated or up to 2.0L turbo/supercharged.
STS allowances
Tires up to 245 mm wide, UTQG treadwear 140 minimum
Wheels up to 8 inches wide, any diameter/offset
Limited slip differentials allowed (including aftermarket) for 2WD cars
High-flow “cat”
Larger brake calipers and rotors
Excluded cars: Audi S4 (V8 engine), BMW M3 (E36, E46) and M5, Mitsubishi
Lancer Evolution, Subaru Impreza WRX STi, Mazda RX-8
STU
is for sedans/coupes with four seats and normally aspirated engines of any
displacement normally aspirated or turbo/supercharged engines up to 3.1L.
STS and STX allowances
No wheel restrictions
Tires for 2WD cars up to 275 mm wide (245 for AWD)
Example of included cars: Audi S4, BMW M3 (E36), Chevrolet Camaro, Dodge
SRT-4, Ford Mustang, Mazda RX-8, Mitsubishi Lancer Evolution, Pontiac
Firebird / Trans Am and GTO, Subaru Impreza WRX STi, Volvo S60 R,
Toyota Supra
Excluded cars: BMW M3 (E46) and M5 (E39)
Refer to the SCCA® National Solo® Rules for full details and specifications on
the Street Touring® allowances.
Street Prepared
The original SCCA® “street” category, Street Prepared allows
any carburetor/fuel injection system and any ignition system. Turbo/supercharger
hardware has to remain standard, but aftermarket boost control
systems/programs and intercoolers are allowed. Exhaust manifolds and systems
are free. Emission controls are not required for competition, but no internal
engine or transmission modifications are allowed beyond factory specs (no cams,
hi-comp pistons, ported heads, etc). Some cars are able to update/backdate
components like engines, brakes, etc (See Solo Rules for details and specifics).
There are no limits on wheels sizes or DOT tires; racing springs and shocks are
the norm.
Street Modified
The top of the “street” categories, Street Modified allows
anything from Stock, Street Touring, and Street Prepared and just about any
engine and drivetrain configuration as long as the engine manufacturer matches
the body manufacturer (see Solo Rules for details). Four-seaters (BMW, Corolla,
Civic, Integra, Neon, Supra, Talon, VW, etc.) run in SM and two-seat sports cars
(Corvette, CRX, M Roadster, Miata, RX-7, MR2, etc.) compete in SM2. Carbon-
fiber hoods, cams, turbo/supercharger kits, etc are welcome, too.
Prepared
These cars are not for the street; they are virtually race-prepared
vehicles for dedicated Solo® competition. Gutted interiors and racing slicks are
the first visual characteristics of these cars and when they crank up, you can tell
these engines weren’t built for bringing home the groceries. Convertible cars are
required to install roll bars per the Solo Rules.
Modified
Except for D and E Modified, these were never ever “street” cars.
They are special built competition vehicles and most of them resemble an open-
wheel Indy car or a closed-wheel LeMans sports racer. DM and EM cars may
have started life on the streets, but just about any engine, drivetrain, or
suspension is permitted. Supercharged rotary engines and V-8 engines are seen
in 1700-pound EM machines and powerful 4-cylinders are common in 1300-
pound DM lightweights.