4.1 BALLAST Permitted. Maximum TOTAL ballast (welded or bolted) 250 pounds (113
kg). See General Regulations 4.2.
4.2 GROUND CLEARANCE Minimum 3-inches (7.6 cmm) from front of car to 12-inches (30.5 cm) behind centerline of front axle, 2-inches (5.1 cm) for remainder of car, except oil pan and exhaust headers.
4.3 PARACHUTE Dual parachutes mandatory. Two separate shroud line mounting points mandatory. See General Regulations 4.8.
4.4 ROLL CAGE Chassis must have manufacturer's name, serial number and date of manufacture. Chassis must meet SFI Spec 10.1D. Plating of chassis prohibited; painting permitted. Chassis must be inspected yearly by ASN and have serialized sticker affixed to frame before participation. Roll cage padding meeting SFI Spec 45.1 mandatory wherever driver's helmet may come in contact with roll cage components. All wiring must be external of the frame rails: the routing of cables, hydraulic or pneumatic lines inside the chassis is permitted. Pressurization of frame rails in lieu of air bottles is prohibited.
4.5 WHEELBASE Minimum 100-inches (2.540 m); maximum 125-inches (3.175 m) on long side. Maximum wheelbase variation from left to right: 2- inches (5.1 cm). Rear tread width cannot be outside of body line nor more than 3-inches (7.6 cm) inside body line. Front tread width must be no more than 6-inches (15.2 cm) inside body line. Measurements will be taken from outside edge of tire to inside edge of body.