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 on rear. No
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 I.M.C.A. Hooiser
G-60, McCreary American Racer (KK-704) allowed.
l.) Tires may be sipped
and grooved.
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….
