CENTRAL MISSOURI SPEEDWAY
2008
MODIFIED SPECIFICATIONS & RULES

1.) Frame/Roll Cage:

a.) Only American made 1960 or newer rear wheel drive passenger car parallel frames (no Sport car frames).

b.) Frame may be cut no further forward than 36 inches from center of rear end housing.

c.) Stiffener allowed left side frame rail maximum 2 inch wide by 4 inch tall.

d.) Frame will be complete and not widened or narrowed and must support roll cage on both sides.

e.) Cross member notched and boxed only for radiator and/or steering clearance.

f.) Outside of tires must be widest part of car. Maximum 78 inches outside of tire to outside of tire.

g.) Wheelbase both sides minimum 108 inches measured center of bottom ball joint to rear housing centerline.

h.) Nothing lower than 4 inches except cross member and oil pan.

i.) Cage continuous loops mounted in at least six places to frame.

j.) Cage tubing minimum 1.75 inch O.D. by minimum .095 inch wall thickness. All welds must be correct and will be inspected by the TECH official.

k.) Minimum one cross bar in halo, and foot protection bar installed.

l.) Minimum 3 driver side door bars with steel door plate 18 gauge or .049 inch minimum thick installed to outside from top bar to bottom bar and from rear down post to 5 inches in front of seat.

m.) Vertical bars must be welded in front of drivers face.

--If tubing 3/8 inch minimum O.D. at least three centered at 4 inches apart minimum.

--If solid bar 1/4 inch minimum O.D. at least four centered at 3 inches apart minimum.

2.) SUSPENSION/STEERING:

a.) ALL components will be steel, OEM, and in stock location except as specified herein.

b.) Lower A-arms must bolt to existing holes on frame, may weld shock mount, may replace bushings with rubber nylon or steel. No offsets.

c.) Front springs may be steel after market non-coil over 4.5 inch O.D. minimum, must be non-progressive and must be installed in original spring tower centerline.

d.) Upper A-arms may be manufactured steel, mounts can be moved and cross shaft may be aluminum.

e.) Sway bar only allowed on front.

f.) Rear front frame may be altered to accept coil and/or leaf springs. Coil springs must be 4.5 inch O.D. minimum, non-progressive, allow to run single spring coil over shocks, may use coil over eliminators, only one coil spring per wheel. No torsion bars or. air bags.

g.) One additional spring allowed for pull or lift bar must be 4.5 inch O.D. minimum and it may be progressive.

h.) All rear coil springs must be tethered to chassis with minimum one aircraft quality cable O.D. 1/8 inch maximum securely clamped both ends.

i.) Rear trailing arms and links may be steel tube with steel rod ends.

j.) One steel non-adjustable shock per wheel and one additional allowed on rear suspension. Allowed to run: Single Spring Coil Over Shock, air, remote reservoir, or Schrader valve type shocks allowed. Front of shocks may be shielded.

k.) Steering shaft and knuckles steel only. Steel steering box only - must be stock located.

l.) Tie rods may be replaced by minimum .625 inch steel rod ends and steel tube.

m.) Stock spindles only and only grinding allowed is for caliper clearance. Bolt spindle savers are allowed.

n.) Cockpit steering may be modified, but remain on left side.

o). Steering quickner, steering wheel, and quick release may be aluminum.

p.) No weight jacking or wheelbase altering devices allowed in cockpit or in driver’s control during competition.

3.) Transmission/Rear End/Drive shaft:

a.) Minimum one forward and one reverse gear and with motor running must be able to move Forward then backward.

b.) No five speeds, in and out boxes.

c.) OEM appearing cases -- except Bert and Brinn allowed.

d.) Automatic must be stock appearing case with stock appearing pump and original bell housing with approved scatter shield or blanket.

e.) Flywheels minimum 8.5 inch, and flex plates minimum 13 inch 153 tooth.

f.) Clutch disc minimum 5.5 inch. Must be steel except housing.

g.) Explosion proof type bell housing except Bert and Brinn.

h.) No cambered rear ends. Steel OEM. Floater rear ends allowed.

i.) Quick change is optional: Steel tubes only; (10) inch ring gear only: pinion and carrier bearing must be tapered, titanium is not allowed; wide five wheel patterns are not allowed: aluminum spools are permitted. Magnesium will be permitted until such date that the cost increases, at which time only, magnesium rear ends purchased prior to that date will be permitted and must have original serial number.

j.) No torque dividing differentials.

k.) Drive shafts steel only, steel slip yokes, minimum 2 inch diameter, painted white.

l.) Drive shaft must be surrounded 360 degrees mounted 6 inches back from front U-joint by .25 inch by 2 inch steel strap or equivalent.

4.) Brakes/Wheels and Tires:

a.) Brakes steel approved OEM drum or disc.

b.) Vented rotors only. May not be modified except drilling for bolt pattern or larger studs.

c.) Handles must be removed from any brake shut off and all four brakes must function.

d.) Front to rear proportion device allowed. No pressure sensitive devices.

e.) All brake lines must be visible.

f.) Steel wheels only maximum bead width 8 inch or 8.75 inch with steel bead lock.

g.) Rim mounted bleeder valves allowed.

h.) Bead lock and or mud plug allowed right side only.

i.) Internal dirt shields allowed.

j.) Steel or aluminum wheel spacers allowed.

k.) Only tires G-60 (KK-704) McCreary American Racer .

l.) Grooving, grinding is allowed.

5.) Electronics/Battery and Starter:

a.) No transmitting or listening devices, retard controls, digital gauges, or monitoring computer devices. Analog tach with memory allowed.

b.) One non-adjustable ignition control box allowed -- must not be within drivers reach. Can Only change high-end revolution setting by an internal setting or changing chip.

c.) No magnetos.

d.) No electronic traction control.

e.) One 12 volt battery allowed, must be securely mounted. Battery disconnected (kill switch) must be mounted so official can reach it from left side, must be marked OFF and ON.

f..) Must have working starter. Engine must start without car being pushed or pulled.

6.) Engine/Cooling System:

a.) American made only, steel block, steel heads and steel oil pan.

b.) Wet oil system only -- external pumps go with engine if claimed. Accumulator allowed, must not be mounted between driver and left side door bars.

c.) ALL pumps must be mounted to front of engine.

d.) No machine work on outside of engine -- castings and fittings must not be changed.

e.) Exhaust must be directly away from cockpit.

f.) Engine must mount minimum 72 inches from rear (bell housing flange) to center rear axle, minimum 11 inches ground to front center of crankshaft and offset within 2 inches of cross member centerline.

g.) Cooling system may be modified, but radiator will be located in front of engine. Coolant overflow tubes must be directed downward to ground between frame rails.

7.) Fuel/Fuel System:

a.) Gas or alcohol -- no performance enhancing additives.

b.) No nitrous.

c.) One 2 or 4 barrel naturally aspirated carburetor. No adjustable spacers. No top flow air cleaner housing.

d.) One fuel filter only and no cool cans.

e.) Mechanical or belt driven pump mounted on to front of engine. Rear mounted fuel pumps are allowed.

f.) Safety fuel cells only maximum 32 gallons mounted in minimum 18 gauge steel container all vent must have check valves.

g.) Fuel cell must mount directly to frame/cage by minimum .125 inch by 2 inch steel straps surrounding the entire cell.

h.) Fuel cell must locate behind rear axle , between tires, minimum 4 inches ahead of bumper, and minimum 6 inches above the ground.

i.) Rear of cell must be protected by tubing extending past both sides, and cell will be no lower than tubing.

8.) WEIGHT:

a.) Car with driver must weigh minimum 2450 pounds after any official race.

b.) Any weight must mount to frame/cage. None inside cockpit, outside body, or on bumpers.

c.) Weights must be painted white (car number a good idea) and mounted with a minimum of two each ½ inch minimum diameter bolts.

d.) All fasteners will be solid steel.

e.) No titanium, magnesium, or carbon fiber products allowed.

9.) BODY:

a.) Body must be same width front to rear and parallel with frame, no wider tires, 66 inch maximum and 53 inch minimum.

b.) Roof can be fiberglass of aluminum, must be rounded, 50 inch maximum 44 inch minimum wide, 56 inch maximum 41 inch minimum long, raked ½ inch minimum 5 inch maximum at front and ½ inch minimum 2 inch maximum rear, and openings both sides 12 inches minimum 18 inches maximum. Must mount body in stock manner, not interior, with front windshield and rear window support post.

c.) Hood widest point 66 inch maximum, may taper to 24 inch minimum no narrower than radiator, enclosed at rear maximum 3 inch rake, and maximum 4 inch drop on sides.

d.) Nose minimum 24 inch and no wider than frame horns.

e.) No panel in front of right door to engine compartment, engine compartment must remain open, no side panels.

f.) Doors 27 inch maximum high, and 72 inch maximum long from rear axle centerline right side. Left side may extend forward to cover foot box.

g.) Rear quarters 27 inch maximum 22 inch minimum high and 34 inch minimum 45 inch maximum long.

h.) Right side door and quarter panel 106 inch minimum to 120 inch maximum long.

i.) Front roof post may have stiffener from bottom front of post to a point no further back than 10 inches must be the same both sides.

j.) Sail panels must slope from roof no further back than deck at rear and no higher than 4 inches at that point. May use Lexan in sail panels. Must be same both sides.

k.) Interior slope is a 4 inch maximum from front to rear and flat across. Top of interior must be flush with top of door and quarter panels.

l.) From ground: top of car 42 inch minimum 52 inch maximum, deck 28 inch minimum 38 inch maximum, to bottom of any body component 4 inch minimum.

m.) Bottom of door and quarter panels may have maximum 4 inch plastic skirting.

n.) Cover at rear is optional, must not exceed outside quarter panels.

o.) May have one spoiler attached at rear of deck, no wider than deck, 8 inch maximum total length measured from deck to include bends.

p.) Lexan or aluminum cowl panel in front of driver allowed, no wider than cockpit, and no further back than steering wheel.

q.) No mirror. No reflective doors or quarter panels.

r.) Numbers must be contrasting color and highly visible. Number on top minimum 20 inch by 4 inch wide. Number on sides minimum 14 inch. On the front and back of the car in a vertical position, minimum of 5 inch high numbers must be affixed on the left and right.

10.) BUMPERS AND RUB RAILS:

a.) Front bumper minimum 1.25 inch O.D. minimum .065 inch wall thick steel. Two bar mounted frame end to frame end with minimum 3/8 inch diameter bolts. No wider than outside frame horns, parallel to ground, center of bars from ground 16 inch minimum 20 inch maximum, bars center to center maximum 6.5 inches apart.

b.) Rear bumper minimum 1.25 inch O.D. minimum .095 wall thick steel mounted with minimum 3/8 inch diameter bolts. No wider than 5 inch outside each frame rail. If more than 5 inch outside frame rail must be capped and bent forward not to exceed outside width of tires. Center of top bar to ground 16 inch minimum 20 maximum.

c.) Rub rails and nerf bars must be steel and must not exceed outside width of tires.

d.) Rear bumpers must be tethered in proximity to their left and right attachment points. Tethers must be as a minimum 1/8” diameter aircraft quality cable secured one end at bumper and other end at chassis.

 

MUST HAVE VISIBLE NUMBERS ON BACK OF CARS

MUST HAVE 2 TETHERS ATTACHED TO REAR BUMPER

REFER TO GENERAL CAR AND SAFETY RULES IN “TRACK RULES AND REGULATIONS “for more pertinent information….