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
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.
RADIATOR
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.
ENGINE
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.
TRANSMISSION
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.
DRIVELINE
No chassis, driveline or suspension components made of carbon fiber allowed.
Only two u-joints per driveline. A drive line shield is mandatory.
REAR END
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.
FRONT END
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.
SUSPENSION
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.
SPRINGS
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.
SHOCKS
Only one shock per wheel. No titanium. No shocks that can be adjusted from the
cockpit will be allowed.
BRAKES
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.
FRONT BUMPER
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