3. Only two roll bar diameters will be allowed. Roll bars of 1 3/4"
diameter will require a minimum of .095" wall thickness. Roll bars of 1
1/2" diameter will require .120" wall thickness.
Seat and steering wheel must be centered in the frame. The seat must be a maximum of 16" from the center of the rear end to back of seat bottom. A high back seat made completely from aluminum is mandatory. No fiberglass or carbon fiber materials are permitted.
Only one radiator allowed and it must be centered squarely, not angled, in front of the motor in a vertical position. No plastic or carbon fiber allowed. No auxiliary cooling tanks or catch cans allowed in driver's compartment.
The engine must be centered in the chassis and placed in an upright position. Engine set back: minimum 56", maximum 66" with 112" absolute maximum tolerance. Set back will be measured from the center of the front axle to the rear machined bell housing surface of the engine. No rear engine cars allowed.
Approved North American manufactured manual shift transmission only, no automatics. No overdrive or
under drive transmissions allowed. No running through reduction gears, transmission must be direct drive to rear end at racing speed. Transmission must have forward, neutral, and reverse gear in good working condition. From a neutral position with the motor running, a car must be able to go forward and backward in a smooth manner. Transmission must bolt to the bellhousing. Car must have a battery and a self starter in working condition. The car must start and move under Its own power.
No chassis, driveline or suspension components made of carbon fiber allowed. Only two u-joints per driveline. A drive line shield is mandatory.
Competition rears only. No hyphoid type rears allowed. No limited slip type rear ends or hubs are allowed. No lockers or two speed rears are allowed. Rear end must have solid aluminum or steel spool only, Rear spindles may be steel or aluminum only. If aluminum it must be a one piece tube and spindle with a minimum outside diameter of 2 7/8" and maximum inside diameter of 2 1/2". Live rear ends with aluminum or steel axles are allowed, The rear end or chassis must not be offset any more than 4" from center of the inside tire width, measured from the inside of the left rear tire to the inside of the right rear tire, at axle height. Must use conventional type quick change rear end only. Axles on closed rear must be steel only.
The front axle must be straight, one piece steel tubing only with no camber adjustments. No split axle or dropped axle allowed. All brackets on front the axle must be bolted or welded, no bird cages or slides. Modified type front spindles only. It is recommended that bearing shafts be made of steel. Chassis may not be offset any more than 4" from center of inside tire width, measured from the inside of the left front tire to the inside of the right front tire at axle height. Front wheels must be fully exposed. No fenders are allowed.
CHASSIS GROUND CLEARANCE
There must be a minimum of 2 1/2" ground clearance from the chassis or anything attached to it, including any part of the body. No metal, lexan, or rubber air dams, fins, spoilers, or skirts are permitted under the car. No ground effects car.
No independent suspensions front or rear, No "A" frames or ball joints may be utilized for steering axis, kingpin only. No four wheel steering allowed that Is actuated by steering wheel. All suspension systems must be mechanical with no form of electrical, radio, or computer assistance. No form of traction control is permitted. No weight jackers or panhard rod adjusters which can be adjusted from the cockpit allowed. Cantilever suspensions and inboard shocks are not allowed. No sway bar adjustments that increase wheel weights from the cockpit, Sway bar quick disconnects are allowed.
Any form will be allowed (torsion bars, coil overs, leaf springs, etc) providing they are made from steel, No carbon fiber or titanium are allowed.
Only one shock per wheel. No titanium. No shocks that can be adjusted from the cockpit will be allowed.
All cars must have four wheel hydraulic brakes in good working order. No carbon fiber or no aluminum rotors and pads. On live rear axles, one Inboard and one outboard brake assembly is allowed.
Must be made from round steel tubing only, with a minimum diameter of 1 1/4" by .095" wall thickness for main bumper and all bracing. It must consist of two rails, an upper and lower. These rails must have four sockets or supports attached to the frame. The four tubes that support the bumper from the four frame sockets must be horizontal. These rails must also be a minimum of 6" apart and a maximum of 12" measured from top to bottom and maintain that measurement for a minimum width of 24" or a maximum width of 30". It must also have an
18" center measured from the ground up to the middle of the bumper. The front bumper may not extend more than 24" in front of front axle center centerline. No V-shaped bumpers, crash area must be flat and vertical for the