minimum of four vertical mounts shall be used. The end can be radiused to a maximum of 200mm. Two of these mounts to be braced or gusseted, a minimum of 150mm back to chassis rails. Box section or pipe brace construction same material as under-rider bar, gusset plating minimum 4mm. If the underrider structure is fully integrated into the front bumper, it must be constructed of a minimum of 3mm plate. (m) Dimensions as per figure T12-1-16(m). Figure T12-1-16(m)
(n) Side rails to be level with bumper, extending 50mm past outer edge of front tyre, with wheels in straight-ahead position, and must be substantially braced to the chassis. (o) Rear wheel guards must be constructed of minimum 50mm x 38mm channel or box steel. They shall not protrude more than 125mm outside the outer edge of the rear tyre. T12-1-17 Suspension (a) Any type of suspension may be used. (b) Any car fitted with coil springs must have the springs securely clamped, or chained in position. A coil-over assembly is regarded as a suitable restraint for the spring to be securely clamped. (c) Suspension and aerofoil must not be able to be adjusted by driver while in the driver's seated position. T12-1-18 Wheels Refer Section T14 on wheels for specifications covering this class. (a) Bead lock rims are not permitted. (b) Bleed off tyre valves are not permitted. T12-1-19 Tyres (a) Maximum width of tread not to exceed 210mm on the track, and overall width not exceed 255mm at or above bumper height. (b) All tyres must have sound casings. (c) Re-grooving of original tread depth is permitted. Increasing original tread width is not permitted. Additional grooving or additional cutting is not permitted. All original tread pattern grooves may not exceed 10mm. (d) When conventional road tyres (front or rear) are used, they must duro 55 or more prior to race. (e) All Hoosier and McCreary/American Racer type front tyres must duro 55 or more prior to race. (f) All Hoosier and McCreary/American Racer type rear tyres must duro 70 or more prior to race.
2010 ELECTRONIC RULEBOOK
Published on Jul 10, 2010