World Challenge Car Facts
Classes
Grand Touring (GT): The allowed body styles within this class are coupe, sedan and convertible. The cars permitted in GT are typically sold in the market as "sports" cars, "sport-touring" cars, or performance versions of "luxury" cars. Forced induction is permitted on cars that come equipped with forced induction stock, or on cars that SCCA Pro Racing has determined need help reaching the target horsepower range. Power output ranges from 425-525 hp. Weight varies depending on power output and tire size. All of the vehicles in GT are rear-wheel drive or all-wheel drive.
Grand Touring Sport (GTS): Includes many cars eligible for the GT class, but at a preparation level much closer to that of a stock vehicle. Additionally, many FIA GT4 class cars are eligible as well as cars built to the 2008/2009-spec Touring Car regulations.
Touring Car (TC): The allowed body styles in this class are coupes, hatchbacks, wagons or sedans. The cars permitted in TC are typically sold as "compact" cars, or "touring" cars. Eligible cars must have realistic seating for four (4) adults. Power output ranges from 180 to 200 hp. Weight varies depending on the power output of the individual drivetrain configurations. Front-wheel, rear-wheel and all-wheel drive configurations are permitted. Forced induction may be allowed on cars that have forced induction systems available from the manufacturer which do not void the factory warranties.
Bodywork Modifications
Bodywork Modifications: Stock body panels may be lightened. Body panels must maintain stock profile, unless alternate panel is approved. Non-essential trim may be removed.
GT: Hood, trunk/decklid and doors may be aftermarket composite components. Vented hoods are approved on a car-by-car basis. Additional aftermarket composite components may be approved if deemed necessary to make a competitive package. Front splitter may protrude 2" from approved front fascia, but may be no wider than the tires at their widest point. Splitter may deviate vertically on the sides and bottom. Each car is permitted to run an approved rear wing.
GTS: Body panels are generally stock. Aftermarket wings are permitted.
TC: Body panels are generally stock. Only OEM wings and splitters are permitted.
Chassis Modifications
Chassis Modifications: Interior may be removed except dashboard. Miscellaneous unused mounting brackets may be removed. Chassis seams may be welded. Doors must be capable of being opened from inside and outside. Driver's seat may be moved rearward as long as the seat back at the driver"s shoulders does not pass the vertical plane of the rear seat shelf. Windshield wipers may be removed, but an operational motor must remain in place.
GT: Windows may be replaced with Lexan.
Safety Modifications
A full rollcage must be used. The rollcages typically have eight main attachment points within the cockpit/trunk. The A-pillar, B-pillar, and roof may be stitch welded to the rollcage. Fuel cells are required, unless stock fuel tank is located between frame rails and the axles.
The driver’s safety equipment includes a racing seat, six or seven-point harness, full-face helmet, head/neck restraint, window net, right-side head restraint net, side impact protection, driver leg support system, multi-layer suit, fire resistant shoes, gloves and underwear and a three-zone fire system.
Engine Modifications
Engines may be blueprinted and balanced. Full-prep engines may replace reciprocating internals. Custom intake manifolds may be allowed if deemed necessary. Engine management systems are free. Ignition system components may be replaced. Must maintain an operational on-board starter.
GT: Dry sump systems are permitted. Forced induction is permitted and may be added to a car if deemed necessary to be a competitive package. Noise limit is 120 dBA. Traction control, and other commonly available electronic driver aids, are permitted.
GTS: Noise limit is 110 dBa. Only electronic driver aids installed from the factory are permitted.
TC: Noise limit is 110 dBA. Only electronic driver aids installed from the factory are permitted.
Drivetrain Modifications
Transmission and differential coolers may be added. Limited-slip differentials are permitted.
GT: Clutch and flywheel design are free, but starter ring gear diameter must be stock. Driveshafts and halfshafts may be modified or replaced, but must be same material and type as OEM. Two sets of gear ratios are permitted. Sequential transmissions are permitted on most vehicles.
Suspension Modifications
The OEM-type of suspension must be retained (i.e. McPherson Strut, double A-arm, etc.). Alternate control arms may be submitted for approval. Shocks and springs are free, but must remain in stock location. Anti-sway bars are free. Bushings are free. Steering geometry may be modified to correct bump steer.
GT: The suspension pick-up points below the top of the tire may be relocated 25mm, and the suspension pick-up points above the tire may be relocated 75mm.
Brake System Modifications
GT: OEM brake systems may be replaced with racing components. The maximum rotor size in GT is 380 mm x 30 mm minimum thickness front and 25 mm minimum thickness rear. The OEM caliper, any 4-piston caliper, or approved 6-piston calipers may be used. Water may be injected into the brake ducts. ABS is permitted. Carbon and Ceramic rotors are not permitted unless stock OEM components are being used.
GTS: Brake pads, fluid, proportioning valves and lines are unrestricted. ABS may be removed or deactivated. Some vehicles may be permitted aftermarket calipers or rotors.
TC: Brake pads, fluid, proportioning valves and lines are unrestricted. ABS may be removed or deactivated. Some vehicles may be permitted aftermarket calipers or rotors.
Wheels
Wheel offset is free, provided the approved bodywork covers the portion of the tire that contacts the track.
GT: The wheel diameter used in the GT class is 18". The maximum wheel width range from 9.5"-13" based on the tire size(s) permitted on each car. Magnesium wheels are permitted.
GTS: Wheel diameters range from 17" to 19", widths from 8" to 11".
TC: The wheel diameter used in the TC class is 17". The maximum wheel width is 8".
Tires
Tires are the Toyo™ Proxes® R888™ DOT-approved tire, in widths ranging from 235mm to 335mm.
