BIG DIAMOND RACEWAY
2010 MODIFIED and SPORTSMAN BODY RULES
1/10/09
Legal bodies must comply with either DIRT specifications or Grandview
specifications. BDR base
specification is DIRT’s, since most chassis builders
are basing production off of DIRT. Any car found with a major
body infraction
before an event (warranted as an unfair advantage) must conform to the
following rules to compete
on the day of event.
1. BODY STYLE AND DIMENSIONS
• All measurements may be taken with or without driver and/or with or without fuel.
• Tolerance permitted on all body dimensions is maximum of ½” (one half inch). This
is a
tolerance NOT an additional dimension to be added to the body dimension.
2. BODY MATERIAL
• Only aluminum or steel will be permitted for all inner and outer body panels.
• A maximum of 4” vertical plastic material extending below the metal body panel
is
permitted. The plastic thickness shall be between .090’’ and .125’’and an overlap of 2”
to
secure to the doors/door extensions will be permitted. Doors/door extensions must still
have a minimum of six inches
of ground clearance including plastic material
• The overall dimensions of the doors and door extensions must meet the specifications.
• The roof must be fiberglass only.
• Hood, hood scoop, windshield cowl, right rear inside tire clearance cover and front spoiler
may be constructed of either fiberglass or aluminum.
• Only CLEAR! lexan will be permitted for the rear spoiler and the rear windows. No
stickers
or writing that obstruct vision will be allowed.
3. ROOF
• The roof must be centered from side to side on roll cage and also be centered on frame
(No
offset bodies). Leading edge of roof must be fastened in a stationary position a
minimum of 33” and a maximum of
48” in front of rear axle centerline. The roof must be
securely fastened at the back and on both ends.
• Length of the roof: maximum 60”, minimum 48”. Width of roof: maximum 52”,
minimum
48”. It must display a turtleback style and shape with at least 3/4’’ belly front to rear and
3/4” side to side. Front lip may not be more than 1/2’’. Side edges may be no longer than
11/8”
break.
• The roof cannot change shape or location while racing.
• Overall height (top of highest point): minimum 52”, maximum 61”, measured
from the
ground. Maximum roof angle is 5 degrees GAUGE!
• 4.2.5 The roof must be one piece fiberglass only and be a single ply, one contour inside
and out. No carbon fiber. Roll bars must be exposed. No vertical metal used to mount
roofs will be permitted covering
the roll bars. The roof must weigh a minimum of ten
pounds.
4. FRONT DOOR POSTS
• Doorposts must be flat aluminum sheet metal Only! They must go in a straight direct line
from the roof to the doors. From a side view they must be seen as a 2” dimension. They
must be no wider than
2”. They may be bead rolled or have a lip for re-enforcement, but
can’t exceed a 3/8” maximum thickness
at that area. The material thickness used may be
a minimum of .050” to a maximum of .090” inches. Only a one-piece construction
will be
accepted! There will be no Tolerance on these measurements. Door-posts must attach
securely to the metal roof
support and doors! They may be bolted with a min. of (2) 3/16”
bolts to the door bracket for the ease of fabrication!
• No lexan vent windows or excessive sheet metal will be permitted in the vent corner
where
the post meets the door panel.
5. REAR WING WINDOWS
• All rear wing panels and windows must resemble a current OEM body style.
• Their upper profile may not protrude above a straight line drawn from the rear of the
roof
to a point 3’’ higher than the rear deck. There must be at least a 2” indent in the profile,
so
as not to make this panel a fast back.
• The maximum base length may not exceed 61’’. Left and right must be of the
same style
and dimension!
• All window styles must be nominally 160 square inches (suggested 10” tall X 16”
long),
clear, smooth lexan with no bends or breaks.
• No writing or decals permitted on the wing windows that may obstruct vision.
• Rear view of the wing window must go in a straight line from top of quarter panel or
bodyline to the roof, with a maximum gradual bow of 2” in the center of wing window.
6. BODY WIDTH AND GROUND CLEARANCE
• Body width (measured anywhere along the body line, front or back): 68” maximum, 64”
minimum.
• Minimum chassis ground clearance 2 1/2”.
• No fan or ground-effects cars are permitted.
• No rubber skirts, fins, or spoilers of any description are permitted under the car.
• A 2” max air deflector is permitted in front of radiator to facilitate cooling.
7. DOOR PANELS
• Side door panel: minimum 60”, maximum 70” in front of centerline of the rear
axle. Doors,
front door extensions and rear quarter panels must be flat and mounted in a vertical
position. They must
remain flat with no louvers, bead rolls, holes or protrusions from top
to bottom. The exception being for rub rails. Doors
may have a max. of a 1” long lip at a
45 deg. outward angle 1/2” away from the sheet metal for the purpose
of reinforcement.
This will be allowed at the top and bottom of the panels. All outside sheet metal, door
panels,
door extensions, air dams, front nose & hood fins must be the same shape, size,
and angle on both sides of the car.
Doors must match each other from side for side.
(Must be symmetrical)
• Bead rolls around the outside perimeter of these panels and the wing windows will be
allowed. Bead roll edges must face towards center of chassis.
• Front door extensions will be permitted up to 20” behind the front axle centerline.
• Front door height must be a maximum of 38” and minimum of 30” from the ground
measured at 60” from rear axle centerline.
• Ground clearance on the bottom of the doors must be a minimum of 6” and a maximum
of 12” from the ground.
• All doors and rear quarter panels may have a maximum lip of 1 1/2” rounded at 90
degrees and facing inward only, on the top and the bottom.
• At the top of the doors and rear quarter panels, a lip angled out at a maximum of 45
deg.,
protruding away from the door no more than 1/2” and no more than 1” in length before it
bends inward
for strength will be permitted.
8. REAR QUARTER PANELS
• Rear quarter panels must match each other. (Must be symmetrical)
• Quarter panels must be a maximum of 47” and a minimum of 40” from the
ground at the
rear and continue in a straight line with top of door.
• A fender flare, up to a maximum of 2” from the body may be used, but the overall
body
width must still be maintained at a 68” maximum.
• Rear quarter panels can extend back to 48” maximum at top and may incline down
to 44”
maximum at bottom measured from center of rear axle to rear of car.
• Ground clearance on rear quarter panels must be a minimum of 8” and a maximum of
16”.
9. REAR SPOILER
• The rear spoiler must be clear one piece lexan with a maximum height of 5” from the
rear
deck and must not have any writing or stickers on it.
• The rear spoiler must be non-adjustable (no hinges or slides).
• No metal Gurney tabs permitted. Lexan may have brake (top only) for rigidity.
• Spoiler maximum height from ground is not to exceed 50”.
• A maximum of four vertical supports may be used to fasten the spoiler to the rear deck.
These supports may not exceed 2” in vertical height and 10” in length.
10. REAR DECK
• Must be a maximum height of 47” and minimum of 40” from the ground.
• Rear deck lid (i.e. trunk lid) must be fully enclosed from quarter panel to quarter panel
and have a minimum height of 9” and a maximum of 14” in vertical coverage behind the
fuel tank.
• Left and right rear trunk lids must be symmetrical in size and shape and show no specific
bulge or extension to cover fuel filler hose or apparatus within the 9” to 14” of vertical
coverage. This
panel must completely cover the fuel cell, filler hoses, and vent lines.
• At the discretion of the Chief Tech Inspector, cars with tall gas tanks may have a step
in
the deck to accommodate the tank.
• The fuel tank must be completely enclosed from the bottom of this panel to the bottom
of
the fuel cell.
• The fuel cell must also have both sides completely covered by sheet metal in addition
to
the container it is enclosed in. Within these dimensions there can be no openings.
• No openings from top of fuel cell to bottom of trunk lid are permitted.
11. HOOD, NOSE, AND FRONT SPOILER
• The hood, nose, and front spoiler can be no wider than 36” and no narrower than 24”.
• The nose-piece must end at the front of the shock towers.
• The spoiler must be separate.
• Shock covers or deflectors may not be part of or riveted to the nose or spoiler exceeding
the 36” width maximum.
• Fabric shock covers are permitted as long as they are used for the prevention of dirt
getting at the shock piston and not used for any aerodynamic advantage.
• The front spoiler must not extend any more than 20” in front of the front axle
centerline.
• The front spoiler must be non-adjustable (no hinges or sliders).
• The hood shall be considered from the front roll cage to on top and even with the front
of
the radiator.
• The nose piece shall start where hood ends and end at the shock towers!
• Both hood and nose may have 2” maximum lip up on both sides following the contour
of
the body. Both lips must be symmetrical!
• The hood, nose, and spoiler may not overlap each other’s location on the frame.
• Any part of hood may not exceed 10 degrees nor can sheet metal have an opening or
extrusion
between the hood and nose.
• The hood must extend over the radiator and have complete sides.
• Front spoiler may have 2’’ maximum lip up or down on both sides following
the contour of
the spoiler, not exceeding the maximum width of 36 inches.
12. HOOD SCOOP
• The hood must be fully enclosed.
• Two options of hood scoops mounted on top of the hood for the purpose of enclosing the
carburetor, or ram air will be permitted providing they meet the following specifications.
• Both style scoops may be made of fiberglass.
• Ram air type scoop: Maximum length, 30” measured from rear motor plate to front
of
hood scoop. Maximum width 18”. The front vertical opening of the scoop can be a
maximum of 6” at the
beginning of the scoop only. The overall height of this scoop must
maintain a minimum of 8” of vertical vision for
the driver. This measurement will be taken
from a horizontal line from the highest point of the hood scoop to the lowest
point of the
front roll cage and/or roof. Hood scoop must be fastened to the hood and completely
enclose the carburetor
and air filter.
• The conventional no ram air scoop: a maximum of 25” is permitted from center of
the
carburetor forward to end of scoop! The width permitted is a maximum of 22”. The height
must maintain a
minimum of 8” of vertical vision from the top of the scoop to the lowest
point under roof or roll cage, and completely
enclose the carburetor and air filter.
13. INTERIOR SHEET METAL
• Any horizontal body support, other than the inner pods, whether in front orrear must be a
maximum of 1” deep by 1” thick tubing or flat stock only.
• No inside or outside wings, spoilers, air foils, or wind deflectors are permitted.
• No double panels that create a wing effect will be permitted.
• A 1” maximum reinforced lip will be permitted on all lexan, but all specified
measurements
must still be maintained.
• All inner sheet metal used must completely cover areas from door to door, quarter panel
to quarter panel. No holes or openings are permitted in this area.
• No vertical fins, air dams, or fairings permitted on the sides or behind the roll cage.
• Sheet metal must be a flat single plane across the inside of the car.
• No covered roll bars are permitted. Sheet metal that is one-piece and part of a body
panel bent around tubing (for purposes of protecting the driver or finishing off panel) is
not considered an aerodynamic
advantage provided it is not to excess.
• No louvers or holes in the interior or exterior sheet metal are permitted with the exception
being the cooling of the radiator, engine, and oil cooler.
• The floor pan or underpan may not be any wider than the frame, from front to back, and
may not have any lips or fins facing downward.
14. NUMBERS
• The Track or series handicapper reserves the right to issue or change a car’s number
to
prevent duplication and maintain proper records.
• Team cars must be clearly distinguishable from one another and use a different number
or letter.
