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04-21-2008, 01:21 AM
this is from: http://www.moutons.org/sccasolo/Rules/street_touring.html
14. STREET TOURING CATEGORY
The Street Touring category of vehicle modifications is meant to fit between the current Stock and Street Prepared categories. This category provides a natural competition outlet for auto enthusiasts using affordable sports sedans equipped with common suspension, engine, and appearance modifications which are fully legal and compatible with street use anywhere in the country. “Dress-up” items such as chrome dipsticks and non-standard filler caps are permitted, provided they serve no other purpose.
Vehicles eligible for this category include all coupes/sedans with a minimum of four seats, four seatbelts; that are non-sports car based with maximum engine displacement of 3.1 liters, normally aspirated and certain small displacement turbocharged sedans. No limited slip differentials are permitted except for factory standard viscous coupler type units.
A sports car based vehicle would include those that are 2+2 variants of 2 seat sportscars. As a guideline, eligible cars would typically come from the D, F, G or H-Stock classes. Note that 3.2 ‘VEHICLE CLASSIFICATION’, also applies to the Street Touring Category, including adding or removing cars from the exclusion lists.
ELIGIBLE VEHICLES:
All vehicles meeting the above criteria
Volkswagen Golf/GTi/Jetta/Beetle/Passat 1.8T
Volkswagen Jetta TDI, Golf TDI
Audi A4 1.8T and TT, non-Quattro
Mazda 323 GTX (AWD)
Mazda 323 GT
Volvo S40 (except T5) and V40
SAMPLE EXCLUDED VEHICLES:
Porsche, all
Datsun Z-car 2+2
Honda CRX
MGB GT
Triumph, all
'04 Audi S4 V8
Under the provisions of Section 1.1 of these rules, Regions are free to allow the previously-listed STR class or any other version of the ST concept which meets their local needs.
If these rules contain errors, oversights, or omissions, the Solo Events Board and the National Office will make the necessary corrections through the use of Technical Bulletins in SportsCar magazine at the earliest
14.1. AUTHORIZED MODIFICATIONS - STS
All Solo II Rules Stock Category allowances and the modifications contained in 14.1 through 14.10.:
Air conditioning systems may be removed in whole or in part. This rule should not be interpreted to allow modification of the heater system.
14.2. BODY WORK
Pedal kits and other interior cosmetic accessories may be added.
The driver and front passenger seats may be replaced, with the following restrictions: The seating surface must be fully upholstered: The top of the seat, or an attached headrest, may not be below the center of the driver’s head. The seat, not including mounting hardware, must weigh at least 15 pounds.
Removal of factory trim (rub strips, emblems, mud flaps)
Alternate steering wheels are allowed except that steering wheels with an integral airbag may not be changed.
Fenders may not be cut or flared but the inside lip may be rolled in order to gain additional tire clearance. Flares that are part of body kits may be attached to the stock fenders. The intention is to allow cars to maximize tire size. Wear marks on inside surfaces of the fender well from tire rub are permitted. However, wear holes or slots completely through a fender well surface (which, in effect, provide additional tire clearance) are not permitted.
Addition of spoilers, body kits, rear wings, etc which do not require removal of standard parts other than the substitution of rear wings/spoilers and valances/bumper covers. The drilling of holes for the purpose of mounting these pieces is permitted.
14.3. TIRES
Tires up to and including a width of 225.
Tires must have a minimum tread wear rating of 140.
Section 13.3.F is not applicable to the Street Touring Rules
Tire models must not appear on the following list, which may be altered at any time by the SEB upon notification of the membership:
No tire models are currently listed.
14.4. WHEELS
Any wheels up to 7.5" in width that fit over stock brakes
14.5. SHOCK ABSORBERS
Shock absorber bump stops may be altered or removed.
Any shock absorbers may be used, provided that the system of attachment and the attachment points are not altered. The number of shock absorbers shall be the same as Stock. No shock absorber may be capable of adjustment while the car is in motion, unless fitted as orignal equipment. MacPherson strut equipped cars may substitute struts, and/or may use any insert. This does not allow unauthorized changes in suspension geometry or changes in attachment points (e.g., affecting the position of the lower ball joint or spindle). It is intended to allow the strut length changes needed to accommodate permitted modifications which affect ride height and suspension travel.
14.6. BRAKES
Cross drilled and/or slotted brake rotors are permitted, same size and type as standard.
Alternate DOT approved flexible brake lines.
Air ducts may be fitted to the brakes, provided that they extend in a forward direction only, and that no changes are made in the body/structure for their use. They may serve no other purpose.
14.7. ANTI-SWAY BARS
Substitution, addition, or removal of any anti-roll bar(s) is permitted. Bushing material, method of attachment, and locating points are unrestricted. Components such as anti-roll bars and strut housings that serve dual purposes by also functioning as suspension locators may not be modified in ways that change the suspension geometry or steering geometry.
14.8. SUSPENSION
Ride height may only be altered by suspension adjustments, the use of spacing blocks, leaf spring shackles, torsion bar levers, or change or modification of springs or coil spring perches. This does not allow the use of spacers which alter suspension geometry, such as those between the hub carrier and lower suspension arm. Springs must be of the same type as the original (coil, leaf, torsion bar, etc.) and except as noted herein, must use the original spring attachment points. This permits multiple coil springs, as long as they use the original mount locations. Coil spring perches originally attached to struts or shock absorber bodies may be changed or altered, and their position may be adjustable. Spacers are allowed above or below the spring.
Suspension bushings may be replaced with bushings of any materials (except metal) as long as they fit in the original location. Offset bushings may be used. In a replacement bushing the amount of metal relative to the amount of non-metallic material may not be increased. This does not authorize a change in type of bushing (for example ball and socket replacing a cylindrical bushing), or use of a bushing with an angled hole whose direction differs from that of the original bushing. If the Stock bushing accommodated multi-axis motion via compliance of the component material(s), the replacement bushing may not be changed to accomodate such motion via a change in bushing type, for example to a spherical bearing or similar component involving internal moving parts. Pins or keys may be used to prevent the rotation of alternate bushings, but may serve no other purpose than that of retaining the bushing in the desired position.
The following allowances apply to strut-type suspensions. Adjustable camber plates may be installed at the top of the strut and the original upper mounting holes may be slotted. The drilling of holes in order to perform the installation is permitted. The center clearance hole may not be modified. Any type of bearing or bushing may be used in the adjustable camber plate attachment to the strut. The installation may incorporate an alternate upper spring perch/seat and/or mounting block (bearing mount). Any ride height change resulting from installation of camber plates is allowed. Caster changes resulting from the use of camber places are permitted
Camber bolts may be installed providing these parts use the original,unmodified mounting points and meet the restrictions specified in 14.5.B. Caster changes resulting from the use of camber bolts are permitted.
Addition or replacement of suspension stabilizers (linkage connecting axle or De Dion to the chassis which controls lateral suspension location) is permitted. Traction bars or torque arms may be added or replaced. A Panhard rod may be added or replaced. Methods of attachment and attachment points are unrestricted.
Camber kits may be installed on vehicles that do not have McPherson strut type suspensions. These kits may include replacement control arms or other parts that are designed specifically to compensate for camber changes resulting from lowering the car. These parts must use the original attachment points. Components which are specifically designed only to facilitate toe adjustments are not permitted.
Changes in alignment parameters which result directly from the use of allowed components are permitted. For example, the dimensional changes resulting from the use of a cylindrical offset bushing which meets the restrictions of 14.8.B are allowed, including those resulting from a change in the pivoting action to
about the mounting bolt, or
about the bushing itself.
Strut bars are permitted with all types of suspension. Strut bars may be mounted only transversely across the car from upper right to upper left suspension mounting point and from lower right to lower left suspension mounting point. No other configuration is permitted. Additional holes may be drilled for mounting bolts. Only bolt-on attachment is permitted. Interior trim panels may be modified to allow installation of strut bars. Holes or slots may be no larger than necessary and may serve no other purpose. This does not permit any modifications to the frame or unibody beyond the allowed mounting holes.
14.9. ELECTRICAL SYSTEM
The make, model number, and size of the battery may be changed but not its voltage. Relocation of the battery or batteries is permitted but not into the passenger compartment. If the battery is relocated and the original battery tray can be removed by simply unbolting it, the tray may be removed, or relocated with the battery. Holes may be drilled for mounting or passage of cables. Longer cables may be substituted to permit relocation. The number of battery or batteries may not be changed from stock. The area behind the rearmost seat is not considered to be within the passenger compartment.
14.10. ENGINE
Engine and transmission must remain unmodified, including emissions equipment, except as noted below:
The air intake system up to, but not including, the engine inlet may be modified or replaced. For naturally aspirated engines, the engine inlet is the inlet to the throttle body or carburetor. For turbocharged or supercharged engines, the engine inlet is the compressor inlet. The existing structure of the car may not be modified for the passage of ducting from the air cleaner to the engine inlet. Holes may be drilled for mounting.
Headers, emissions-legal.
The engine management system parameters and operations may be modified only via the methods listed below. Any and all modifications must meet or exceed the applicable US DOT emissions standards for the year, make, and model of the car. These allowances also apply to forced induction cars, except that no changes to standard boost levels, intercoolers, or boost controls are permitted. Boost changes indirectly resulting from allowed modifications are permissible, but directly altering or modifying the boost or turbo controls, either mechanically or electronically, is strictly prohibited.
Reprogrammed ECU may be used in the standard housing. Traction control parameters may not be altered. Altered engine controllers may not alter boost levels in forced induction engines.
Electronic components may be installed inline between an engine's sensors and ECU. These components may alter the signal coming from the sensor in order to affect the ECU's operation of the engine management system. Example: fuel controllers that modify the signal coming from an airflow sensor.
Fuel pressure regulators may be replaced in lieu of electronic alterations to the fuel system. It is not permitted to electronically modify the fuel system AND replace a fuel pressure regulator.
Ignition timing may be set at any point on factory adjustable distributor ignition systems.
VTEC controllers and other devices may be used which alter the timing of factory standard electronic variable valve timing systems.
The mass airflow sensor must remain in its approximate original location.
All STS vehicles must comply with the Federal 49-state safety and tailpipe emissions test requirements as a minimum.
Any mechanical shift linkage may be used.
Any accessory pulleys and belts of the same type (e.g., V-belt, serpentine) as standard may be used. This allowance applies to accessory pulleys only (e.g., alternator, water pump, power steering pump, and crankshaft drive pulleys). It does not allow replacement, modification, or substitution of pulleys, cogs, gears, or belts which are part of cam, layshaft, or ignition drive or timing systems, etc. Any crankshaft damper or pulley may be used. SFI-rated dampers are recommended. Supercharged cars may not change the effective diameter of any pulley which drives the supercharger.
Engine mounts may be replaced, but must attach in the factory location(s) without additional modification or changes. Engine position may not be changed. The amount of metal in a replacement mount may not be increased relative to the amount of metal found in a stock mount for the particular application. Solid metal mounts are specifically prohibited. Any non-metallic inserts may be used.
Hydraulic shock type rear engine locators, or bobble struts may be replaced by manufacturer’s performance part, or aftermarket replacement part. This part must retain factory dimensions and attachment points, including factory design. (example: If factory locator/bobble strut is gas or hydraulic piston type, replacement part must be gas or hydraulic piston type. No solid mounts may be substituted.)
14.11. STX
The STX class expande the vehicle eligibility limits beyond those specified for STS, and adds a limited number of allowed modifications. The allowances are as follows:
All allowances in STS carry over, including street tires, emissions, etc., except as follows:
Replace 14.2 F. with “The total area when viewed from the top of the airfoil sections of all wings shall not exceed 8 square feet. The area shall be computed by multiplying the width and depth of the wing without regard to the curvature of the wing. Any airfoil shadowed by another airfoil with more than six inches between them will have its own projected area added to the wing area calculation.”
Replace 14.8.E with “Camber kits, also known as camber compensators, may be installed. These kits consist of either adjustable length arms or arm mounts that provide an adjustment to the effective length of a control arm. Alignment outside the factory specifications is allowed. The following restrictions apply:
On double/unequal arm suspensions, only the upper arms OR lower arms may be modified or replaced, but not both.
On arm-and-strut (MacPherson/Chapman) suspensions, the lower arms may be modified/replaced OR other methods of camber adjustment as allowed by paragraphs 14.8 B., C., or D. may be used, but not both.
On swing or trailing arm suspensions, the main arms may not be modified but locating links/arms may be modified or replaced.
The replacement arms or mounts must attach to the original mounting points. All bushings must meet the requirements of 14.8 B. The knuckle/bearing housing/spindle assembly cannot be modified or replaced.
All restrictions regarding body type carry over.
Engine size allowance: up to 5.1, normally aspirated and 2.0, forced induction (single turbo or supercharger).
Rim restriction: maximum width of 8", diameter/offset unrestricted. Tire restriction: max width 245 mm .
Only standard (as defined in Section 12.4) limited slip differentials (LSD) are allowed on AWD vehicles. For AWD vehicles that did not come with any type of limited slip differential (including center differential or transfer case), a single aftermarket LSD may be added. 2WD vehicles may use any LSD unit.
High flow catalytic converters are allowed, but must attach within six inches of the original unit. Multiple catalytic converters may be replaced by a single unit. The inlet of the single replacement converter may be located no further downstream than 6" along the piping flow path from the original exit of the final OE converter.
Suspension bump stops may be altered or removed.
Brake rotors may be replaced with any rotor of equal or larger diameter made from a ferrous or aluminum alloy. Calipers are unrestricted, but must mount to the original attachment points. Drum brakes may be replaced with disk brakes of a diameter equal to or greater than the inside diameter of the standard drum part.
Original equipment ABS braking systems may be electrically disabled, but not removed or altered in any other way.
Original equipment traction control systems may be electrically disabled, but not removed or altered in any other way.
Additionally excluded cars: BMW M3 (E36 and E46), BMW M5 (all), Mazda RX-8, Mitsubishi Evo 8, Subaru Sti.
14. STREET TOURING CATEGORY
The Street Touring category of vehicle modifications is meant to fit between the current Stock and Street Prepared categories. This category provides a natural competition outlet for auto enthusiasts using affordable sports sedans equipped with common suspension, engine, and appearance modifications which are fully legal and compatible with street use anywhere in the country. “Dress-up” items such as chrome dipsticks and non-standard filler caps are permitted, provided they serve no other purpose.
Vehicles eligible for this category include all coupes/sedans with a minimum of four seats, four seatbelts; that are non-sports car based with maximum engine displacement of 3.1 liters, normally aspirated and certain small displacement turbocharged sedans. No limited slip differentials are permitted except for factory standard viscous coupler type units.
A sports car based vehicle would include those that are 2+2 variants of 2 seat sportscars. As a guideline, eligible cars would typically come from the D, F, G or H-Stock classes. Note that 3.2 ‘VEHICLE CLASSIFICATION’, also applies to the Street Touring Category, including adding or removing cars from the exclusion lists.
ELIGIBLE VEHICLES:
All vehicles meeting the above criteria
Volkswagen Golf/GTi/Jetta/Beetle/Passat 1.8T
Volkswagen Jetta TDI, Golf TDI
Audi A4 1.8T and TT, non-Quattro
Mazda 323 GTX (AWD)
Mazda 323 GT
Volvo S40 (except T5) and V40
SAMPLE EXCLUDED VEHICLES:
Porsche, all
Datsun Z-car 2+2
Honda CRX
MGB GT
Triumph, all
'04 Audi S4 V8
Under the provisions of Section 1.1 of these rules, Regions are free to allow the previously-listed STR class or any other version of the ST concept which meets their local needs.
If these rules contain errors, oversights, or omissions, the Solo Events Board and the National Office will make the necessary corrections through the use of Technical Bulletins in SportsCar magazine at the earliest
14.1. AUTHORIZED MODIFICATIONS - STS
All Solo II Rules Stock Category allowances and the modifications contained in 14.1 through 14.10.:
Air conditioning systems may be removed in whole or in part. This rule should not be interpreted to allow modification of the heater system.
14.2. BODY WORK
Pedal kits and other interior cosmetic accessories may be added.
The driver and front passenger seats may be replaced, with the following restrictions: The seating surface must be fully upholstered: The top of the seat, or an attached headrest, may not be below the center of the driver’s head. The seat, not including mounting hardware, must weigh at least 15 pounds.
Removal of factory trim (rub strips, emblems, mud flaps)
Alternate steering wheels are allowed except that steering wheels with an integral airbag may not be changed.
Fenders may not be cut or flared but the inside lip may be rolled in order to gain additional tire clearance. Flares that are part of body kits may be attached to the stock fenders. The intention is to allow cars to maximize tire size. Wear marks on inside surfaces of the fender well from tire rub are permitted. However, wear holes or slots completely through a fender well surface (which, in effect, provide additional tire clearance) are not permitted.
Addition of spoilers, body kits, rear wings, etc which do not require removal of standard parts other than the substitution of rear wings/spoilers and valances/bumper covers. The drilling of holes for the purpose of mounting these pieces is permitted.
14.3. TIRES
Tires up to and including a width of 225.
Tires must have a minimum tread wear rating of 140.
Section 13.3.F is not applicable to the Street Touring Rules
Tire models must not appear on the following list, which may be altered at any time by the SEB upon notification of the membership:
No tire models are currently listed.
14.4. WHEELS
Any wheels up to 7.5" in width that fit over stock brakes
14.5. SHOCK ABSORBERS
Shock absorber bump stops may be altered or removed.
Any shock absorbers may be used, provided that the system of attachment and the attachment points are not altered. The number of shock absorbers shall be the same as Stock. No shock absorber may be capable of adjustment while the car is in motion, unless fitted as orignal equipment. MacPherson strut equipped cars may substitute struts, and/or may use any insert. This does not allow unauthorized changes in suspension geometry or changes in attachment points (e.g., affecting the position of the lower ball joint or spindle). It is intended to allow the strut length changes needed to accommodate permitted modifications which affect ride height and suspension travel.
14.6. BRAKES
Cross drilled and/or slotted brake rotors are permitted, same size and type as standard.
Alternate DOT approved flexible brake lines.
Air ducts may be fitted to the brakes, provided that they extend in a forward direction only, and that no changes are made in the body/structure for their use. They may serve no other purpose.
14.7. ANTI-SWAY BARS
Substitution, addition, or removal of any anti-roll bar(s) is permitted. Bushing material, method of attachment, and locating points are unrestricted. Components such as anti-roll bars and strut housings that serve dual purposes by also functioning as suspension locators may not be modified in ways that change the suspension geometry or steering geometry.
14.8. SUSPENSION
Ride height may only be altered by suspension adjustments, the use of spacing blocks, leaf spring shackles, torsion bar levers, or change or modification of springs or coil spring perches. This does not allow the use of spacers which alter suspension geometry, such as those between the hub carrier and lower suspension arm. Springs must be of the same type as the original (coil, leaf, torsion bar, etc.) and except as noted herein, must use the original spring attachment points. This permits multiple coil springs, as long as they use the original mount locations. Coil spring perches originally attached to struts or shock absorber bodies may be changed or altered, and their position may be adjustable. Spacers are allowed above or below the spring.
Suspension bushings may be replaced with bushings of any materials (except metal) as long as they fit in the original location. Offset bushings may be used. In a replacement bushing the amount of metal relative to the amount of non-metallic material may not be increased. This does not authorize a change in type of bushing (for example ball and socket replacing a cylindrical bushing), or use of a bushing with an angled hole whose direction differs from that of the original bushing. If the Stock bushing accommodated multi-axis motion via compliance of the component material(s), the replacement bushing may not be changed to accomodate such motion via a change in bushing type, for example to a spherical bearing or similar component involving internal moving parts. Pins or keys may be used to prevent the rotation of alternate bushings, but may serve no other purpose than that of retaining the bushing in the desired position.
The following allowances apply to strut-type suspensions. Adjustable camber plates may be installed at the top of the strut and the original upper mounting holes may be slotted. The drilling of holes in order to perform the installation is permitted. The center clearance hole may not be modified. Any type of bearing or bushing may be used in the adjustable camber plate attachment to the strut. The installation may incorporate an alternate upper spring perch/seat and/or mounting block (bearing mount). Any ride height change resulting from installation of camber plates is allowed. Caster changes resulting from the use of camber places are permitted
Camber bolts may be installed providing these parts use the original,unmodified mounting points and meet the restrictions specified in 14.5.B. Caster changes resulting from the use of camber bolts are permitted.
Addition or replacement of suspension stabilizers (linkage connecting axle or De Dion to the chassis which controls lateral suspension location) is permitted. Traction bars or torque arms may be added or replaced. A Panhard rod may be added or replaced. Methods of attachment and attachment points are unrestricted.
Camber kits may be installed on vehicles that do not have McPherson strut type suspensions. These kits may include replacement control arms or other parts that are designed specifically to compensate for camber changes resulting from lowering the car. These parts must use the original attachment points. Components which are specifically designed only to facilitate toe adjustments are not permitted.
Changes in alignment parameters which result directly from the use of allowed components are permitted. For example, the dimensional changes resulting from the use of a cylindrical offset bushing which meets the restrictions of 14.8.B are allowed, including those resulting from a change in the pivoting action to
about the mounting bolt, or
about the bushing itself.
Strut bars are permitted with all types of suspension. Strut bars may be mounted only transversely across the car from upper right to upper left suspension mounting point and from lower right to lower left suspension mounting point. No other configuration is permitted. Additional holes may be drilled for mounting bolts. Only bolt-on attachment is permitted. Interior trim panels may be modified to allow installation of strut bars. Holes or slots may be no larger than necessary and may serve no other purpose. This does not permit any modifications to the frame or unibody beyond the allowed mounting holes.
14.9. ELECTRICAL SYSTEM
The make, model number, and size of the battery may be changed but not its voltage. Relocation of the battery or batteries is permitted but not into the passenger compartment. If the battery is relocated and the original battery tray can be removed by simply unbolting it, the tray may be removed, or relocated with the battery. Holes may be drilled for mounting or passage of cables. Longer cables may be substituted to permit relocation. The number of battery or batteries may not be changed from stock. The area behind the rearmost seat is not considered to be within the passenger compartment.
14.10. ENGINE
Engine and transmission must remain unmodified, including emissions equipment, except as noted below:
The air intake system up to, but not including, the engine inlet may be modified or replaced. For naturally aspirated engines, the engine inlet is the inlet to the throttle body or carburetor. For turbocharged or supercharged engines, the engine inlet is the compressor inlet. The existing structure of the car may not be modified for the passage of ducting from the air cleaner to the engine inlet. Holes may be drilled for mounting.
Headers, emissions-legal.
The engine management system parameters and operations may be modified only via the methods listed below. Any and all modifications must meet or exceed the applicable US DOT emissions standards for the year, make, and model of the car. These allowances also apply to forced induction cars, except that no changes to standard boost levels, intercoolers, or boost controls are permitted. Boost changes indirectly resulting from allowed modifications are permissible, but directly altering or modifying the boost or turbo controls, either mechanically or electronically, is strictly prohibited.
Reprogrammed ECU may be used in the standard housing. Traction control parameters may not be altered. Altered engine controllers may not alter boost levels in forced induction engines.
Electronic components may be installed inline between an engine's sensors and ECU. These components may alter the signal coming from the sensor in order to affect the ECU's operation of the engine management system. Example: fuel controllers that modify the signal coming from an airflow sensor.
Fuel pressure regulators may be replaced in lieu of electronic alterations to the fuel system. It is not permitted to electronically modify the fuel system AND replace a fuel pressure regulator.
Ignition timing may be set at any point on factory adjustable distributor ignition systems.
VTEC controllers and other devices may be used which alter the timing of factory standard electronic variable valve timing systems.
The mass airflow sensor must remain in its approximate original location.
All STS vehicles must comply with the Federal 49-state safety and tailpipe emissions test requirements as a minimum.
Any mechanical shift linkage may be used.
Any accessory pulleys and belts of the same type (e.g., V-belt, serpentine) as standard may be used. This allowance applies to accessory pulleys only (e.g., alternator, water pump, power steering pump, and crankshaft drive pulleys). It does not allow replacement, modification, or substitution of pulleys, cogs, gears, or belts which are part of cam, layshaft, or ignition drive or timing systems, etc. Any crankshaft damper or pulley may be used. SFI-rated dampers are recommended. Supercharged cars may not change the effective diameter of any pulley which drives the supercharger.
Engine mounts may be replaced, but must attach in the factory location(s) without additional modification or changes. Engine position may not be changed. The amount of metal in a replacement mount may not be increased relative to the amount of metal found in a stock mount for the particular application. Solid metal mounts are specifically prohibited. Any non-metallic inserts may be used.
Hydraulic shock type rear engine locators, or bobble struts may be replaced by manufacturer’s performance part, or aftermarket replacement part. This part must retain factory dimensions and attachment points, including factory design. (example: If factory locator/bobble strut is gas or hydraulic piston type, replacement part must be gas or hydraulic piston type. No solid mounts may be substituted.)
14.11. STX
The STX class expande the vehicle eligibility limits beyond those specified for STS, and adds a limited number of allowed modifications. The allowances are as follows:
All allowances in STS carry over, including street tires, emissions, etc., except as follows:
Replace 14.2 F. with “The total area when viewed from the top of the airfoil sections of all wings shall not exceed 8 square feet. The area shall be computed by multiplying the width and depth of the wing without regard to the curvature of the wing. Any airfoil shadowed by another airfoil with more than six inches between them will have its own projected area added to the wing area calculation.”
Replace 14.8.E with “Camber kits, also known as camber compensators, may be installed. These kits consist of either adjustable length arms or arm mounts that provide an adjustment to the effective length of a control arm. Alignment outside the factory specifications is allowed. The following restrictions apply:
On double/unequal arm suspensions, only the upper arms OR lower arms may be modified or replaced, but not both.
On arm-and-strut (MacPherson/Chapman) suspensions, the lower arms may be modified/replaced OR other methods of camber adjustment as allowed by paragraphs 14.8 B., C., or D. may be used, but not both.
On swing or trailing arm suspensions, the main arms may not be modified but locating links/arms may be modified or replaced.
The replacement arms or mounts must attach to the original mounting points. All bushings must meet the requirements of 14.8 B. The knuckle/bearing housing/spindle assembly cannot be modified or replaced.
All restrictions regarding body type carry over.
Engine size allowance: up to 5.1, normally aspirated and 2.0, forced induction (single turbo or supercharger).
Rim restriction: maximum width of 8", diameter/offset unrestricted. Tire restriction: max width 245 mm .
Only standard (as defined in Section 12.4) limited slip differentials (LSD) are allowed on AWD vehicles. For AWD vehicles that did not come with any type of limited slip differential (including center differential or transfer case), a single aftermarket LSD may be added. 2WD vehicles may use any LSD unit.
High flow catalytic converters are allowed, but must attach within six inches of the original unit. Multiple catalytic converters may be replaced by a single unit. The inlet of the single replacement converter may be located no further downstream than 6" along the piping flow path from the original exit of the final OE converter.
Suspension bump stops may be altered or removed.
Brake rotors may be replaced with any rotor of equal or larger diameter made from a ferrous or aluminum alloy. Calipers are unrestricted, but must mount to the original attachment points. Drum brakes may be replaced with disk brakes of a diameter equal to or greater than the inside diameter of the standard drum part.
Original equipment ABS braking systems may be electrically disabled, but not removed or altered in any other way.
Original equipment traction control systems may be electrically disabled, but not removed or altered in any other way.
Additionally excluded cars: BMW M3 (E36 and E46), BMW M5 (all), Mazda RX-8, Mitsubishi Evo 8, Subaru Sti.