BIG DIAMOND SPEEDWAY 2017
358 MODIFIED, SPORTSMAN
PREFACE TO BIG DIAMOND 2016 RULE BOOK.
THE RULES AND/OR REGULATIONS SET FORTH HEREIN ARE DESIGNED TO PROVIDE FOR THE ORDERLY CONDUCT OF RACING EVENTS AND TO ESTABLISH MINIMUM ACCEPTABLE REQUIREMENTS FOR SUCH EVENTS. THESE RULES SHALL GOVERN THE CONDITION OF ALL BIG DIAMOND SPEEDWAY, AND BY PARTICIPATING IN THESE EVENTS
ALL BIG DIAMOND SPEEDWAY COMPETITORS/MEMBERS ARE DEEMED TO HAVE TO COMPLY WITH THESE RULES. NO EXPRESS OR IMPLIED WARRANTY OF SAFTEY SHALL RESULT FROM PUBLICATIONS OF OR COMPLIANCE WITH THESE RULES AND/OR REGULATIONS. THEY ARE INTENDED AS A GUIDE FOR THE CONDUCT OF THE SPORT
AND ARE IN NO WAY A GUARANTEE AGAINST INJURY OR DEATH TO
PARTICIPANTS, SPECTATORS OR OTHERS. IT IS UNDERSTOOD THAT FOR AND IN
CONSIDERATION OF THE GRANT OF A PIT PASS THE HOLDER DOES HEREBY RELEASE, INDEMNIFY AND SAVE HARMLESS THE MANAGEMENT, PROMOTORS AND OWNERS OF
BIG DIAMOND SPEEDWAY OF AND FROM ANY AND ALL LIABILITY, NEGLIGENCE OR
OTHERWISE AND FROM ANY AND ALL CLAIMS, SUIT, ACTIONS AND DEMANDS FOR DAMAGES DUE TO PERSONAL INJURY, DEATH OR DAMAGE TO PERSONAL PROPERTY WHICH MAY ARISE FROM ACCIDENT, THIRD PARTIES OR OTHERWISE WHILE ON THE PREMISES OF BIG DIAMOND SPEEDWAY AND AGREES THAT BY ACCEPTING A PIT PASS IS THE HOLDER THEREFORE EXPRESSLY ASSUMES THE RISK OF INJURY INCLUDING DEATH, TO HIMSELF OR INJURY TO HIS PERSONAL PROPERTY WHILE ON SAID PREMESIS.
MANAGEMENT RESERVES THE RIGHT TO MAKE AMENDEMENTS TO RULES FOR SAFETY OR OTHER CONSIDERATIONS OR WHEN DEEMED BENEFICIAL TO THE MAJORITY OF COMPETITORS. PRODUCTS OR DEVICES NOT SPECIFICALLY MENTIONED IN THIS RULE BOOK ARE NOT NECESSARILY LEGAL AND SAID PRODUCTS OR DEVICES WILL BE
EVALUATED ON AN INDIVIDUAL BASIS TO DETERMINE IF THEY ARE IN THE BEST
INTEREST OF RACING COMPETITION. MANAGEMENT RESERVES THE RIGHT TO OUTLAW ANY PRODUCT OR DEVICE NOT SPECIFICALLY PERMITTED BY THIS RULE.
READ CAREFULLY ALL RULES RELATING TO CONSTRUCTION AND SAFETY OF CARS ARE AN ABSOLUTE MINIMUM PROTECTION AND IN NO WAY GUARANTEE YOUR SAFETY.
THE STRUCTURAL INTEGRITY OF YOUR CAR AND THE SAFETY THEREOF IS TOTALLY THE RESPONSIBILTY OF YOU AND YOUR CAR MANUFACTURER. YOU MUST UNDERSTAND THAT AUTOMOBILE RACING IS A VERY DANGEROUS SPORT AND THAT ALL CONTAINED RULES AND REGULATIONS ARE MERELY PROCEDURES THAT ARE TO BE
FOLLOWED IN ORDER TO PRODUCE GOOD COMPETITION. EVEN AFTER STRICT COMPLIANCE WITH THE SAME, INJURY AND/OR DEATH MAY OCCUR AS A RESULT OF YOUR COMPETING IN AUTO RACING. ANY AND ALL PRODUCTS, DEVICES OR PARTS FOUND TO BE ILLEGAL UNDER THE PROVISIONS OF THIS RULE BOOK MAY BE CONFISCATED BY THE RACE TRACK. REFUSAL
OR FAILURE TO SURRENDER SIAD ILLEGAL PRODUCTS, DEVICES OR PARTS TO THE RACE TRACK UPON DEMAND AT THE TIME OF THE RULE INFRACTION SHALL RESULT IN AN IMMEDIATE SUSPENSION OF THE ILLEGAL CAR AND THE DRIVER FROM THE TRACK. A
FINE OF UP TO $1,000.00 MAY BE ENFORCED BY THE SPEEDWAY.
BIG DIAMOND SPEEDWAY GENERAL RULES AND REGULATIONS
*No computers or computer operated components of any kind allowed in or on any racing vehicle
1. Management reserves the right to reject any entry.
2. Management has the right to check any car anytime at no cost or protest fee. Refusal
will result in forfeiture of all monies earned at the particular event or if prior to competing,
the right to compete.
3. Any deviation to the following rules must be passed by the technical inspector.
4. Quick release safety belt and shoulder harnesses must be used, must be 3” nylon. All belts and arm restraints must bear the date of manufacture and may not be in use for more than 2 years from the date of manufacture. Anti-submarine belts and arm restraints must be used at all times when the car is on the track or getting ready to go on the track (line up areas). Driver’s side window net be in place when the car is on the track and in line up areas.
5. All drivers must wear flame resistant uniform, Nomex or similar fabric
and flame resistant gloves and shoes kept in acceptable condition (no holes, rips or tears). Flame resistant underwear, hood, and socks are recommended. These items will be checked from time to time and if not acceptable, must be replaced in order to compete.
6. It is recommended that helmets meet specifications set for in the Federal Motor Vehicle Safety Standard Regulations or meet the specifications set forth by the American National Standards Institute Inc. Snell Foundation Specifications SA 2005 Helmets or newer are recommended. Helmets marked “M” for Motorcycle are NOT ALLOWED. Full-face helmets are mandatory.
7. Hoods are mandatory at all times and must extend over and to the front of the radiator cap.
8. All cars must have self-starter in working condition. Cars not able to start on their own, on the initial start and require a “push” must start at the rear of the field.
9. 2-WAY RADIO OR TRACK TEAM COMMUNICATIONS ARE NOT PERMITTED.
10. Fan shield or shroud is mandatory.
11. Wheel weights are not allowed. Bolted on wheel covers are allowed.
12. Open drive shaft cars must have a retaining hoop and/or approved “tunnel” located at the forward end of driveshaft. Drive shaft must be painted WHITE. A 1/8” STEEL PLATE UNDER DRIVER’S SEAT IS MANDATORY FOR ALL CLASSES.
13. No electric or cam driven fuel pumps allowed.
14. No oil cookers, breathers or oil lines allowed in or near driver area.
15. Ignition switch and fuel shut-off must be painted bright orange.
16. All mandatory safety components such as bumpers, rub rails, hoods, fenders and body panels must be securely fastened and on car at all times, subject to the approval of the technical inspector. No weighted bumpers or rub rails.
17. No two cars may look exactly alike.
18. A fire extinguisher is required, securely mounted within the driver’s reach. This must be approved by the technical inspector. Gauge must be readable. An on board Halon type (no dry powder) fire system is mandatory . Must have discharge heads in driver and fuel tank areas.
19. No 4 wheel or front wheel drive cars permitted.
20. No V-6 engines allowed in any race division.
21. All rulings by the technical inspector and scorers are final.
22. Any car found to be illegal after the feature will be disqualified and lose all points and money earned for the night. Driver and/or car owner of any car found to be illegal after the feature, as far as engine or fuel, may be suspended for the minimum of the following two race meets.
Major offenses, as determined by the management, could result in total suspension and loss of points earned from the entire year.
23. Driver assumes responsibility for the action of their pit crew at all times and shall be the
sole spokesperson for their car owner and pit crew in any and all matters pertaining to the race event and with officials in charge.
24. Raceceivers in good working order must be used while cars are on the track. Only one
frequency is permitted and must match the track frequency for line up and yellow flag
communication purposes only. Those who refuse to listen to in car demands will be penalized.
25. Ignition: All ignition wires, and ignition boxes MAY NOT PASS THROUGH OR BE
LOCATED IN DRIVER’S AREA. The only exception is a single power wire. NO IGNITION WIRES may be grouped in with any other wire of any kind and may not be covered by tape or any other kind of wire loom. ALL IGNTITION WIRES must be clearly visible and routed in a way that is easy to follow. One ignition system per car. The white and any other unused wire must be clipped as close as possible to the box. MSD #8982 start/restart control & MSD #8680 adjustable timing control or any other remote or manual timing control will NOT BE PERMITTED.
26. Steel cooling fans only – all classes.
27. Any thing not covered in rule book is subject to official’s discretion.
BECAUSE IT IS NOT ADDRESSED
DO NOT ASSUME IT IS LEGAL!
ENGINE: 9:1 COMPRESSION
ENGINE BLOCK: NORTH AMERICAN V-8 ENGINES PERMITTED
A. OEM production engine blocks under 352 cubic inches but no less than 340 cubic inch
displacement. Bowtie, SVO, MOPAR D.C. After market blocks, OEM copies, are permitted. OEM
deck height and cam locations are required on all blocks.
B. An inspection plug must be installed in the oil pan, 1” pipe plug minimum, in line with the first two connecting rods.
C. 358 cubic inch (plus 3 cubic in. tolerance) is maximum displacement.
D. Flat top or dish pistons only. No dome. No offset pins. Three ring grooves. Top of the piston may be cut for proper compressions ratio but must remain flat or dished.
E. 9:1 compression ratio, maximum reading on the “Whistler” 9:4:1.
OEM stock production crankshaft required, must be manufactured by the manufacturer of the engine block used. No aftermarket crank allowed. Stock stroke only, no interchanging of crankshafts allowed. No bore/stroke combinations. You must use the crank for the block used.
Chevy Motor Example: If you use a 350 cubic inch Chevy block or Chevy bowtie block you must use a 350 Chevy crankshaft with a 3.48” stroke only. The following part numbers are the only 350 Chevy cranks that may be used: Steel-1182, 1184, 2690, Cast iron-310514, 3912335,
3932442, and 3932444. Ford Motor Factory forged steel of Factory case iron and must display the factory part number. Mopar Motor Example: If you use a Chrysler block, MOPAR D.C P3870873 X or R, you must use a Factory.
1. No offset grinding of journals, stock stroke only.
2. No polishing, grinding or knife edging of crankshaft or counterweights. You may debur sharp edges and pattern marks on crankshaft.
3. They must fit OEM templates.
4. Drilling permitted for balancing only.
5. Original factory casting number must remain on the crankshaft.
6. Balancing the crankshaft will be achieved by drilling the front and rear counterweights only.
All holes must be complete holes and changing the original shape of the counterweights will not be permitted. No metal removed from throw side of the crankshaft. Original templates will be
used to tech. the engines.
1. Any steel connecting rod permitted.
2. The only lengths to be used are: Chevrolet 5.7”, Ford 6.0”, and Mopar 6.125”.
One Holley 650 CFM, Part No. 4777, Model No. 4150, with Primary venturi 1-1/4”, Secondary
venturi 1-5/16”, Throttle bore 1-11/16”, or Holley CFM HP series with 4, 1-1/4” diameter venturi
and 1-11/16” Throttle bore. A 750 CFM carburetor, HOLLEY HP #0-80535-1, is permitted. No external modifications allowed including modifications visible looking into the venturi and bores.
Must maintain stock venturi, throttle bore and booster dimensions. Conventional Holley fuel feed locations only. No cutting or polishing and must remain stock appearing in all respects.
You may remove the choke horn. These are the only carburetors that may be used on the 9:1 engine. No individual velocity stacks allowed on carburetors. Maximum 2” thick spacer between the carburetor and the intake manifold is permitted; any additional spacer must be fully welded (360 degrees) to intake manifold. No moving parts in intake manifold or spacer.
Only cast iron OEM stock production cylinder head, cast by the manufacturer of the approved engine block is permitted. Aftermarket heads are not allowed.
Chevrolet: Any OEM stock production cast iron cylinder head or Chevy bowtie cast iron head. Raised runner or dart head is not allowed.
FORD: Any OEM stock production cast iron cylinder head or SVO Ford cast iron head is allowed.
Boss Ford raised runner head is not allowed.
CHRYSLER: Any OEM stock production cast iron cylinder head or MOPAR D.C W2 head is allowed.
Hemi head is not allowed.
1. Ports may be matched to intake manifold but must not exceed ½” depth.
Sandblasting, bead blasting, porting, polishing and welding prohibited. Valve seat
area may be opened or machined but not to exceed 1” in depth from the bottom of
the valve seat. 1” depth in the valve seat area does not allow you to machine over
the hump into intake ramp, machining should not be visible looking into the intake
or exhaust port perpendicular to the port face. Combustion chamber modification
accepted. Head may be machined for large push rods. 3/8” thick exhaust port
plates allowed. Valves must remain in stock location.
2. No acid dipping or porting permitted
3. Conventional style Rev Kit may be used. Push rod must be removed from top,
cannot be attached internally. No carbon fiber valve parts allowed.
No dry sump oil system and no external oil pump or oil system allowed.
No air pump of any style allowed.
No overhead camshaft permitted.
Gasoline or methanol Sunoco fuel permitted. Oxygenated race gas is NOT allowed. Use Sunoco type of fuel only. No blending of fuels, this will result in a DIRTY fuel test. The base fuel used for our testing will be the track Sunoco fuel.
ENGINE INSPECTION will occur at random. Big Diamond Speedway may request removal of an intake manifold, cylinder head or oil pan of any engine at any time. Any engine violation will incur the loss of ALL money for the event and a point’s penalty. A second offense will include indefinite suspension. An engine inspection will be required before reinstatement.
ENGINE: BRODIX ALUMINUM SPEC HEAD 10.5:1 COMPRESSION
Maximum of 10.5 on the whistler.
Carburetor: See page 8
Engine Block: See page 7
Must be cast aluminum production intake.
Chevrolet #SP CH, Ford # SP FO, and Mopar #SP MO only.
1. Spec heads will be supplied with CNC bowl blend and intake port match.
2. No grinding or blending of CNC machine work.
3. No grinding, polishing, or “undercover porting” anywhere on casting.
4. No welding or epoxy permitted.
5. No titanium valves.
6. Titanium valve spring retainers are permitted.
7. Maximum valve size, 2.080 intakes and 1.600 exhausts, stem diameter 11/32”.
8. Valve angle, position, seats and guides to remain as cast.
9. No altering or reshaping valve guides.
10. Angle milling maximum 1.0 degree.
11. Serial numbers will remain untouched.
12. Brodix is the authorized repair facility. Notifications, authorization and documentation must be supplied to Big Diamond Speedway for all repairs.
Any forged or cast steel crankshaft, OEM stroke for engine block used, is permitted.
Solid steel only, any length.
Flat top or inverted dome 3 ring only, compression ratio Maximum 10.5:1. Maximum overbore
.060”, 363 cubic inch maximum.
SECTION 1 – MANDATORY SAFETY RULES FOR MODIFIED CLASS
THE FOLLOWING RULES APPLY TO THE MODIFIED CLASS. THESE RULES ARE
MANDATORY AND WILL BE STRICTLY ENFORCED.
All cars are subject to Inspection at any time. All cars must be free from mechanical
defects and be in safe racing conditions. Track or Series officials’ decisions regarding
any safety infractions will be final.
1. Only round steel roll over bars may be used. Front and rear roll bars must be connected at top in a cage type configuration. Two round horizontal side bars on each side are mandatory.
The top side bar must be a maximum of 29” below the top roll bar. Proper bracing and
triangulations on front and rear roll bars is required. It is highly recommended that all roll bar bracing be a minimum diameter of 1.50”x .095” wall thickness. A minimum of one diagonal bar across the top of the roll cage is mandatory.
2. The rear main roll bar hoop must be a minimum of 26” measured across from outside to outside of tubing and must maintain that measurement from the bottom all the way to the top of the cage. Bottom of the real roll bar must be welded to the 2”x4” frame (no outriggers). The front roll bar must be measured and constructed the same way except that the allowable taper in the
frame rules will govern the width dimensions. Only two steel roll bar diameters will be
permitted, 1.750”x.095” wall and 1.50”x .120” wall.
3. Shock resistant roll bar padding must fully cover all bars that may come in contact with the driver’s head while strapped in the seat. Center steering housing, lines and fittings must be covered with shock resistant roll bar padding. The steering wheel center must be padded. The starter housing and any other points of contact that could potentially injure the driver must be adequately padded.
4. Driver’s seat must be securely fastened to frame or cage in six spots with a minimum of six (6) 3/8” bolts, four (4) on bottom and two (2) on the seat back. Seats must have a minimum 1/8” steel plate under and up the back 4” and be as wide as seat. A minimum 8” wide by 1/8” steel plate will be added to the top of this plate and centered and extend to the top seat mount. The seat must be one piece high back type with padded rib protectors only. The seat must be made of aluminum (no fiberglass). Seat and steering must be centered in frame.
Head, neck and shoulder supports are HIGHLY RECOMMENDED and will be
MANDATORY in the future.
5. All cars must have a functional padded head rest, which must be in line with center of driver’s head, if not built into the seat.
6. All cars must be equipped with 3” lap belt and 3” shoulder harness with 2 belts over the shoulder. Buckles must be quick release type. There must be a minimum of one submarine strap. All belts must be securely fastened to the frame or cage. Bolts may not be inserted through webbing for mounting. Cam lock seat belts are not allowed. When belts have cotter pin locks, the pins must be in place. Belts may be rejected if not in good condition. A sternum strap shoulder harness is highly recommended. Belts more than 2 years old will not be permitted.
7. All drivers must wear a helmet (Snell SA 2005 or new is mandatory), arm restraints, fire retardant driving gloves, shoes, and full fire suit are mandatory. The following items are highly recommended:
8. All cars must have a steel wind screen of substantial material with a maximum individual opening of 2”x1”x1/16” (no chicken wire or aluminum). Screen must cover entire windshield area left to right across the cage and from top of cage down to hood or cowl. Clear lexan or safety glass windshields may be used for additional protections if they are in the driver’s line of
sight. They must be shatterproof and mounted behind the screen enabling drive to wipe them clean. Any additional windshield must not obstruct the emergency exit of the driver.
9. Adequate window openings on both sides of the car must be maintained for emergency exit of the driver. The minimum opening size is that which will allow a rectangular box with
dimensions of 12” high x 18” wide x 30” long to be passed through the inside of the car from one window through to the other side. Any obstacles other than the driver’s head rest, which prohibit the passing of the inspection box through the cockpit, must be removed.
10. All cars must have a drive shaft cover. Cars with open drive shafts must have a tunnel made from a minimum of 1/8” thick steel which extends from 2” under front edge of seat to the back of the transmission, covering the shaft, “U” joint and output flange on top and both sides. It
must extend completely down to floorboard. It must be held in place with a minimum of four (4) 3/8” diameter bolts at bottom connected to a substantial cross-member. This drive shaft cover must be a solid unit with no cut-away for lightening purposes. NOTE: Closed drive type car with torque tube or ball that already have a 360 degree covering from “U” joint back to seat
will be accepted as is. To protect the driver, any suspension link such as a torque arm, coil over or trailer bar inside the driver’s compartment must have a steel cable 1/4” in diameter minimum or clamp connecting it to a substantial cross-member to limit its range should it break loose. It is also recommended that all these parts have no sharp edges and be padded. Open drive shaft cars must have two steel rings, diameter to suit, 1/4” wall thickness, 2”wide, each fastened by two 5/8 grade 5 bolts to torque arm side plates or frame. Must be installed around each drive shaft universal joint.
11. Firewalls, front and rear, are mandatory. The rear firewall must extend from top of fuel cell to belly pan to isolate the driver from the fuel cell, minimum .050” thick aluminum or steel. A minimal amount of sheet metal may be cut out for drive shaft clearance. The front firewall must isolate driver from the engine compartment.
12. Belly pan is mandatory and must extend from front firewall to rear firewall and be fastened securely. It is mandatory to have a separate floor to protect the driver’s feet in the event the belly pan comes off. This extra floor must be attached to the frame, cross member or both and extend from the front firewall past front edge of the seat.
13. All crews must carry an operable fire extinguisher pit side capable of extinguishing fuel and oil fires.
14. On board fire extinguisher (Halon type) for modified and sportsman is mandatory.
15. Battery must be properly secured and must have top and terminals completely covered by rubber. NOTE: It is recommended that batter be mounted outside of driver’s compartment and
that a battery shut-off switch be mounted and marked ON/OFF with a bright colored paint. The switch should be clearly visible and easily identified by the safety crew.
16. All cars must have an ignition switch which is easily accessible within the driver’s
compartment. The ignition switch should be marked ON/OFF with a bright colored paint and be clearly visible and easily accessible to the safety crew.
17. A fuel shut-off valve must be mounted within easy reach of the driver and the safety crew.
It must be labeled in a clearly visible location with words FUEL ON/OFF with a bright colored paint.
18. All fuel lines, power steering lines and fittings running through the driver’s compartment must be an approved braided type line. Plastic or glass fuel filters are not permitted. Any high pressure lines, fittings or any lines carrying hot fluids that run through the driver’s compartment must be encased or shielded by a deflector to prevent driver injury. All oil coolers must be
mounted below inner sheet metal. Louvers will be allowed for cooling oil coolers only.
19. All cars must have four (4) wheel hydraulic brakes in good working order. Brake tests may be conducted.
20. Rear wheels must have a minimum of five (5) lug nuts; a minimum of three (3) lug nuts are required on front wheels. Knock off hubs are not allowed.
a. MODIFIED FUEL TANK: PLASTIC DROP TANK NOT PERMITTED
An alcohol approved fuel cell encased in steel or aluminum container, with bladder and/or foam, is recommended. A square or rectangular plastic tank will be accepted.
b. ALL TANKS: Fuel tank height 12”, minimum from ground to bottom of tank. Fuel tank must also be centered inside of frame rail. Fuel lines must siphon from the top only. There must be a one-way safety check valve in the vent line. The fuel tank must be mounted behind driver. Fuel tank must be secured by at least two steel straps; each strap must be a
minimum of 1”x .125” and bolted with at least 5/16” diameter grade five (3 line) bolts. A third strap in opposite direction is recommended.
22. A horizontal bar with minimum diameter of 1.00”x.095” wall thickness must be mounted behind the fuel cell to protect it from rear crash damage.
23. Exhaust headers must be safe for the driver and must not point down towards the track surface.
24. No mirror or reflecting device that will enable the driver to the see the car behind is
25. Inspectors reserve the right to request body or sheet metal to be replaced and/or painted if they have sharp edges or do not adequately represent the sport.
26. A minimum of two (2) throttle return springs and a toe loop on throttle pedal are required.
27. Fuel drums are not permitted on track premises.
28. Cockpit adjustable components, except brake bias and pan hard rod, are not permitted.
SECTION II – MODIFIED & SPORTSMAN BODY RULES
ALL MEASUREMENTS WILL BE TAKEN WITHOUT DRIVER.
Aluminum or steel will be required for all inner and outer body panels. Fiberglass roof is required. Hood scoop may be fiberglass. The nose piece and front spoiler may be made of an approved plastic. Only clear lexan will be allowed for the rear spoiler and the rear wing windows.
1. Roof must be centered on roll cage and 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.
2. Length of roof: maximum 60”, minimum 48”. Width of roof: maximum 52”, minimum 48”, must be a turtleback style and shape. The roof contour must fit roof template patterns left to right and front to back (no flat roofs). Roofs cannot change shape or locations while racing.
3. Overall height (top of highest point): minimum 52” maximum 61” measured from the ground. Maximum roof angle is 5 degrees on a gauge with no deflections in roof contour.
4. Roof must be a single ply, one contour inside and out. Roll bars must be exposed from any angle. No vertical metal used to mount roofs will be allowed covering the roll bars.
FRONT DOOR POST:
1. Door post must be 2” wide from the side view from the roof all the way down to the door. The post must be flat, no angle shape or round tubing will be permitted. No lexan vent window or excessive sheet metal will be allowed in the vent corner where the post meets the door panel.
REAR WING WINDOW:
1. Window must conform to measuring template as shown in the “Body Style Diagrams”. The name of the body style picked must match the wing window design and be lettered as such
on the front center of the roof. All window style must be clear smooth lexan with no bends or breaks. No lettering or decals allowed on the wing windows.
2. Rear view of the wing window must go in a straight line from top of quarter panel or body line to the roof with a maximum gradual deflection of 2” in the center of wing window. Side view of the rear wing window must extend from the roof to the rear top of quarter panel in a straight line or in accordance with the window style chosen. A maximum of 3” higher than rear deck height at that point will be allowed.
3. Sportsman can use sail panels. Must be used on both sides. Minimum of 61″ and a maximum of 65″ and extend to end of quarter panel.
BODY WIDTH AND GROUD CLEARNACE:
1. Body width (measured anywhere along the body line, front to rear): 68” maximum, 60”
minimum. Minimum body and chassis ground clearance 2.50”. No fan or ground effect cars.
No rubber skirts, fins or spoilers are permitted under the car.
1. Side door panel: minimum 60”, maximum 70” in front of centerline of the rear axle. Door must be straight up and down within that measurement. Front door extension will be allowed 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 door must be a minimum of 6” and a maximum of 12” from the ground.
Door and rear quarter panel may have a maximum lip of 1.50” rounded at 90 degrees and facing inward only, on the top and bottom.
REAR QUARTER PANEL:
1. Rear quarter panels must match each other. They must be a maximum of 45” and a
minimum of 40” from the ground at the rear and continue in a straight line with top of door (see Modified Body Diagram). You may use a fender flare, up to a maximum of 2” from the body but overall body width must still be maintained at a 68” maximum. Rear quarter panel 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 panel must be a minimum of 8” and a maximum of 16”.
1. The rear spoiler must be clear lexan with a maximum height of 3” from the rear deck and must not have any lettering or decals on it. The rear spoiler must be non-adjustable, no hinges or slides.
2. A maximum of three vertical supports may be used to fasten the spoiler to the rear deck.
These supports may not exceed 2” in vertical height and 10 inch in length.
1. Must be a maximum height of 47” with ½” tolerance and minimum of 40” from the ground.
2. Rear deck 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” vertical coverage. This panel must
completely cover the fuel cell, filler hoses and vent lines. 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 additions 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. Any vent line nozzle used for catch can purposes must be mounted on the left quarter panel.
HOOD, NOSE AND FRONT SPOILER:
1. The hood, nose and front spoiler can be no wider than 36” and no narrower than 24”. Shock covers or deflectors may not be part or riveted to the nose or spoiler exceeding the 36” width maximum. Fabric shock covers are allowed as long as they are used for the prevention of dirt
getting to the shock and not used for any aerodynamic advantage. The front spoiler may not extend any more than 20” in front of the front axle centerline. The front spoiler must be nonadjustable,
no hinges or sliders. Hood shall be considered from the front roll cage to the top and even with the front of the radiator. Nose piece shall start where hood ends to a maximum of 20” in front of axle centerline. They all may have 2” maximum lips up or down on both sides
following contour of the body. 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. Hood must extend over the radiator and
have complete sides. Hood and sides must be easily removed for engine inspection.
2. Front windshield opening for the optional ram air style scoop, a 10” vertical measurement from lowest point of roof or roll cage to highest point on hood, including the hood scoop, is required. For the conventional type scoop an 8” vertical measurement will be required.
1. An optional hood scoop mounted on top of the hood for the sole purpose of enclosing the carburetor and air filter will be allowed providing it meets the following specifications; both style scoops may use fiberglass and the option of keeping the hood fully enclosed will be allowed.
2. Ram air type scoop: Maximum length, 30” from start to finish, maximum width 18” from start to finish. 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 10” of vertical vision for the driver. This measurement will be taken from a horizontal line from the highest
point of the hood and completely enclose the carburetor and air filter. A tolerance of ½” will be allowed on three dimensions.
3. Conventional non ram air scoop: A maximum of 25” is allowed from center of the carburetor forward. The width allowed 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.
INTERIOR SHEET METAL:
1. Any horizontal body support, other than the inner pods front or rear, must be a maximum of 1” deep by 1” thick tubing or flat stock only. No inside wings, outside wings, spoilers, air foils or wind deflectors are allowed. No double panels will be allowed that creates a wing effect. A 1”
maximum reinforced lip will be allowed on all lexan, but all allowable 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 allowed in this area.
2. No vertical fin, air dam or faring allowed on the side or behind the roll cage. Sheet metal must be a flat single plane across the inside of the car. No covered roll bars for aerodynamic purpose are allowed. Louvers or holes in the interior or exterior sheet metal are not permitted with the
exception to cool the radiator, engine or oil cooler. The belly pan may not be any wider than the frame from front to back and may not have any lips or fins facing downward.
1. Track handicapper will assign car number. Whenever possible a requested number will be assigned, but the handicapper reserves the right to issue all numbers in order to prevent duplication and maintain proper records.
2. Team cars must be clearly distinguishable from one another and use a different number or letter.
3. Numbers and letters will be limited to three digits. If three digits are used two shall be primary numbers. Numbers are required on roof, nose, rear deck and both doors.
4. All numbers and letters must be a minimum of 18” high on the roof and doors and 8” high for the rear deck and nose. All numbers and letters must be of equal size.
5. If numbers “3” “6” or “9” are used make sure that they are distinguishable. Do not let nerf bars block visibility.
SECTION III – CHASSIS SPECIFICATIONS FOR MODIFIED CLASS
1. Only 2”x4” box frames are permitted between axle centers front and rear. The 4” side must be vertical. Frame rails must be steel only. All 2”x4” rails must be .120” wall thickness. At the discretion of the officials, it may be necessary to drill a 3/16” hole in frame rail for inspections of
thickness. No other holes will be allowed. Round tubing allowed for the frame rails will be 1.50”x.095” wall or 1.750”x.095” wall.
2. Frame width shall be as follows; Front (at shock towers): 24” minimum, 35” maximum. Rear: 26” minimum, 35” maximum. The minimum frame width at the rear roll bar must be 26”. Measurements are to be taken from outside of the frame rails, these measurements shall be
taken at both top and bottom of frame at its longest length. Clips, sub-frames etc. are
considered the frame.
3. Minimum length of the of the 2”x4” frame rail must start at 14” in front of rear axle centerline and extend to front of the radiator. Kick up material must be same specifications as the roll cage or frame material. Left and right frame rails both top and bottom, must be in a straight line
and be an equal distance from drive line centerline along the total length of frame.
4. Titanium or carbon fiber materials are not allowed on the chassis.
1. Only round steel roll over bars may be used. Front and rear roll bars must be connected at top in a cage type configuration. Two round horizontal side bars on each side are mandatory.
The top side bar must be a maximum of 20” below the top roll bar. Proper bracing and
triangulation on front and rear roll bars are required. It his highly recommended that all roll bar bracing be a minimum diameter of 1.50”x.095 wall thickness steel tubing. A minimum of one diagonal bar across the top of the roll cage is mandatory.
2. The rear main roll bar hoop must be a minimum of 26” measured across from outside to outside tubing and must maintain that measurement from the bottom all the way to the top of the cage.
3. Only two steel roll bar diameters will be allowed, 1.750”x.095 wall or 1.50”x.120 wall.
4. Gussets are recommended at all roll cage joints.
1. Seat and steering wheel must be centered in the frame. The seat must be a maximum of 16” from the center of the rear axle to back of seat bottom (see body Diagram). A high-back seat made completely from aluminum with padded rib protector is mandatory. No fiberglass or
carbon fiber materials are permitted. Head, neck, and shoulder supports are HIGHLY
RECOMMENDED and will be MANDATORY in the future.
1. Only one (1) radiator allowed and it must be centered squarely, not angled, in front of engine in a vertical position. No plastic or carbon fiber allowed. No auxiliary cooling tanks or catch cans are allowed in driver’s compartment.
1. The engine must be centered in the chassis and placed in an upright position. Engine set back: minimum 56” maximum 66” with ½” 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. Rear engine car is not permitted.
1. 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 axle at racing speed. Transmission must have forward,
neutral and reverse gears in good working order. From a neutral position, with the engine running, a car must be centered in the chassis.
2. Car must have a battery and starter motor in good working order. The car must self start and move without assistance.
1. Chassis, driveline or suspension components made of titanium or carbon fiber are not permitted. Only two (2) universal joints per driveline, a drive line shield is mandatory (see safety
rules for detailed requirements). All of driveline must be centered in chassis.
1. Competition rear axle only. Hypoid, limited slip, locker spool or two speed rears are not
permitted. Rear axle must have solid aluminum or steel spool only. Axles on the closed rear must be steel. Rear spindles must be steel. Live rear axle with aluminum or steel axle is permitted. The rear axle or chassis may not be offset more than 4” measured from the inside of
the left rear tire to the inside right rear tire at axle height (see Chassis Diagram for rear axle offset details). The center line of rear axle must be centered in the chassis.
1. The front axle must be straight one piece steel tubing without camber adjustments. Split or dropped axle is not permitted. All brackets on the front 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 more than 4”, measured from the inside of the left
front tire to the inside of the right front tire axle height (see Chassis Diagram for front end offset details). Front wheels must be fully exposed. Fenders are not permitted.
WHEELBASE AND THREAD:
1. Wheelbase: minimum 106” maximum 110”. This measurement will be taken from the center of the rear axle to the center of the front axle, both left and right side with a maximum tolerance of ½”.
2. Tread width: front-maximum 86” minimum 74”. Rear treads, maximum 86” minimum 80”. Width measurements will be taken from outside of the tire side wall at axle height with a maximum tolerance of ½”.
CHASSIS GROUD CLEARANCE:
1. There must be a minimum of 2.50” ground clearance from the chassis or anything attached to it, including any part of the body. Metal, lexan, rubber air dam, fin, spoiler or skirt is not permitted under the car. Ground effect devise not permitted.
1. No independent suspension front or rear. No “A” frames or ball joints may be utilized for steering axle, kingpin only. Four wheel steering actuated by steering wheel is not permitted. All suspension systems must be mechanical with no form of electrical, radio or computer assistance.
1. Any form will be permitted; torsion bar, coil spring, leaf spring etc. providing they are steel.
Fiberglass, carbon fiber or titanium is not permitted.
1. One shock per wheel, no titanium.
1. Must be made from round steel tubing with a minimum diameter of 1.25”x.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.
1. Round steel tubing with a minimum diameter of 1.50”x.095” wall thickness for main bumper and all bracing is required. It must consist of two rails, an upper and lower, which must have
four sockets and horizontal support bars attaching to the frame. These rails must also be a minimum of 10” apart and a maximum of 16” measured from top to bottom and maintain that measurement for a minimum width of 64” or a maximum width of 86”. The rear bumper or any side bars cannot extend past the outside of tire sidewall on both sides. It must have an 18”
center measured from the ground up to middle of bumper. The rear bumper may not exceed 52” in back of rear axle centerline.
2. No V-shaped bumpers. Crash area must be flat and vertical for the full width of bumper. Bumper must have an anti-hook brace from outer hoop to the bumper mount extensions. When rear side rails are used they must be inside the body’s quarter panel. All rounded ends and no sharp edges.
1. Must be made of round steel tubing with a minimum diameter of 1.50”x.095” wall thickness.
All bracing must be a minimum diameter of 1.50”x.095” wall thickness. Maximum wall thickness must be.095” with no solid bars or ballast added inside. Rub rails must be outside of body panels but may not exceed the outside edge of the tires. The exception is the left rub rail, which
may extend an absolute maximum of 2” outside the left rear tire sidewall. Rub rail ends must be rounded with no sharp edges and bend at a gradual 90 degrees.
2. Rub rails must be a minimum of 50” long, end to end.
3. Double rub rails allowed on drive side only. If abused, will be removed on case by case basis.
MUFFLER AND EXHAUST SYSTEM:
1. Only two mufflers are permitted. Mounting position will be optional. The exhaust must exit safe for the driver and must not be directed to the track surface.
2. Any manufacturer of exhaust header is allowed, but header material is limited to steel or stainless steel. Cross over pipes connecting cylinder banks are not permitted.
3. Borla or Raptor mufflers are required.
1. Any ballast weight must be mounted within the vertical plane formed by the frame rail, must be securely fastened with at least 2 (two) ½ grade 8 bolts, and must remain stationary while racing. All ballast must be painted white and have car number on it. Weight ballast ma not be fastened to the inner side rail jigs or on any part of the roll cage above the inner sheet metal.
1. Aluminum wheels are permitted for the modified and sportsman class. Magnesium or carbon fiver wheels are not permitted. Bleed off valves are allowed.
2. Bead locks are mandatory.
3. Wheel covers or hub caps on the inside of the wheels are not allowed. Wheel covers are
allowed outside of the wheels providing they are one piece, attached as part of the bead lock and maintain a minimum thickness of .095” with a 4.5” diameter center hole. All wheel covers must be approved by management.
4. Foam inserts allowed and must display car number.
5. Wheel covers attached by dzus buttons are not permitted.
6. Wheel covers must be attached with all bead lock bolts and be inside of bead lock
1. American Racer tires must be used on all 4 corners at all times. The manufacturer will mark all legal tires.
2. No tire softener or liquid of any kind is allowed inside or outside of the tire. Heating the tire by torch, blanket or exhaust system etc. is not permitted. Any type of tire inner liner is prohibited. Durometer readings may be taken at random.
1. 2350 LB – Brodix Aluminum Spec. A 75 LB weight break will be given to modified
competitors that are running race gas.
2. 9:1 cast iron head engines-2325 LB. Ford N and Mopar cast iron head engines, w/650 CFM only.
3. Sportsman with aluminum wheels-2425lbs. Sportsman with steel wheels 2350. Crate sportsman 2350.
Weight is checked, with driver, after each event. Track scales will be official, no protests or appeals are allowed on their finding.
3. One trip over the scale only. If not sure of weight check it before warm-up starts.
4. Weight violation is subject to complete disqualification at the discretion of the official.
BIG DIAMOND SPEEDWAY RACE PROCEDURE RULES
1. A driver may get out of one car and drive another, but after driving the second car he may not get back into the first car. Any change must be reported to the pit steward and handicapper. Driver must drive the car he qualified for the feature.
2. No car will be allowed to run in rear of heat for practice laps.
3. Get your car on track promptly for start of race. When pit steward calls your car for race, get it out on track in time. Cars not on track in time will have to start in the rear. After starter has given signal to pole car to move, any car coming on track automatically falls in at rear of field.
4. When race is running the next event will be lined up behind turn 2. When race is over the next event should immediately enter track. Any car not in turn 2 by half way point will start to rear of field.
5. Once a car is reported scratched from a race that car may not be re-entered in that race.
6. A. In event of yellow flag and car not driven immediately to the starting line or to the rear field, will be considered involved in the accident.
B. After all cars have passed the scene of the accident, the remaining cars that have not assumed a position will go to the rear of the pack in the order they leave the accident.
C. If race must be stopped no work may be performed to car on the track. If you have problems go to the pits and upon return to track fall in at rear of field.
D. If you are involved in an accident and can move your car into the infield please do so race can proceed, if you cannot drive your car cooperate with towing operators so car can be removed from track as quickly as possible. ALL DRIVERS MUST STAY IN CAR UNLESS INJURED. ANY
DRIVER THAT LEAVES THEIR CAR WILL HAVE THEIR CAR TOWED INTO THE INFIED AND CAR WILL NOT BE REMOVED UNTIL THE END OF THE NIGHT.
E. If you drop out of the race into the infield while the green flag is out and the leader
passes your position and then the yellow flag comes out, your car will be scored as
being 1 lap down to the field.
7. Yellow flag laps will not be scored. Restart after red flag will revert to last completed
8. During yellow flag period, cars must run single file.
9. Single file restarts when 5 laps or less remain, in the feature event.
10. Use good judgment when car malfunctions by staying out of the racing groove so as not to hinder others.
11. Car must be signed in at pit office ninety (90) minutes prior to starting time or will start at rear of qualifying events.
12. Please refrain from use of profane language or repeated criticism of officials. This could result in suspension of car and driver. Driver is responsible for any misbehavior of any person or
persons signed into the pits with their crew.
13. Alcoholic beverages are not allowed in pits until races are complete. Violators will be
suspended from competition for a time designated by officials. Driver is responsible for anyone with their car.
14. No one allowed in infield and scoreboard area except track crew, firemen, ambulance crew, tow truck operators and photographers. Credentials are required. Any pit crew member found in the infield without permissions could cause their car to be disqualified.
15. Any unsportsmanlike conduct on race track may lead to disqualification of car and/or driver for time designated by officials. No warnings.
16. Any party who willfully or maliciously uses a race car on the track or in the pit area to injure, destroy or damage another person or personal property will be suspended plus subject to arrest.
17. “Set downs” (such as rough riding) will be for the following event. Instead of “set downs” driver may be penalized finishing spots on the same night.
18. You must be in assigned starting position for each event before the pace vehicle moves, if not you start at the rear of field.
BIG DIAMOND SPEEDWAY GENERAL PROCEDURE RULES
1. Any car desiring a warm-up must help “pack the track”. Registered driver, with all safety equipment in place, is the only one eligible to take a car on the race track.
2. Cars that spin out on the track will try to get going immediately and not stop the race.
Anyone deliberately stopping the race will be disqualified or penalized.
3. Any car spinning out twice without contact or bringing out the caution flag twice will be
4. Cars running more than 2 laps down or hopelessly out of competition and creating a hazard will be black flagged, at the starter’s discretion.
5. Cars moving through infield or pit area will do so with extreme caution. Any driver not doing so will be suspended.
6. No one is permitted at the pit gate at any time.
7. No one is allowed to ride in or on car at anytime.
8. Unsportsmanlike conduct on track or pit area may lead to suspension of car and/or driver.
9. Anyone who pulls a car across track, track entrance or scale at any time will be suspended for
balance of season.
10. Anyone fighting in pits or on track will be subject to disciplinary action. ANY DRIVER WHO EXITS THEIR CAR ON TRACK AND GOES AFTER ANOTHER DRIVER WILL HAVE ACTION TAKEN
AGAINST THEM. WE WILL NOT TOLERATE FIGHTING!
11. Drivers and pit personnel should stay in their own area. Anyone in a fight at another pit area will automatically be at fault. Anyone caught fighting will result in a $500.00 fine or a automatic two week suspension, final decision by officials.
12. There will be no harassment of officials, tow truck operators, safety crews or ambulance
crews. Anyone striking or threatening an official with bodily harm will be suspended
13. Any driver involved in an accident will be checked by the ambulance crew.
14. Drivers may not get out of their race car on track, except in an emergency.
15. There will be no repair to a car while on the track. Car must be taken to infield or pits, no repairs by tow crews. TOW TRUCKS WILL NOT HOLD YOUR CAR IN THE AIR WHILE YOU WORK ON IT. FOR SAFTEY PLEASE ALLOW TOW TRUCKS TO COMPLETELY DROP AND UNHOOK CAR
BEFORE YOU START YOUR WORK.
16. Any car causing the yellow flag to be thrown or involved in an accident will go to rear of field whether on the first lap or not.
17. Any crew person or driver going to announcer’s booth causing a disturbance will cause the car they are with to risk disciplinary action. Once again driver is responsible for crew.
18. Car must finish the consi to qualify for the feature.
19. In event of more than one consi, first none qualified cars will flip for first alternate.
20. Any car involved in an accident will be checked by officials before resuming to race.
21. No infield running. Drivers coming off infield causing accident will be disciplined.
22. Turn 1 is the only exit off the race track. Any driver that exits the track thru turn 2 will
be disqualified. Turn 2 exit is for scale use only.
POST RACE INSPECTION
Any car that is ordered to the post race technical inspection area will be checked by the officials to determine if it has conformed to the general as well as the specific rules.
Any member who fails to tear down an engine for inspection, when requested to do so by the track official, will be subject to a fine of not less than $500.00 and/or definite or indefinite suspension from
If a competitor believes that another competitor running in the same event has or will obtain a significant unfair competitive advantage by some action that they believe is in violation of the track rules, they may protest such action to a track official. The protest must be made in writing, signed and dated by the driver, crew chief or car owner within ten (10) minutes after completion of the event. Only a driver finishing on the lead lap can protest another drive also
on the lead lap. Once a protest is made it cannot be withdrawn. Protesting another car does not give you the right to watch over the tech inspector performing the protest. The subject being protested will be the only thing checked. Each protest shall be accompanied by a $1,200.00 protest fee. The track official shall decide whether the matter is valid and if so shall decide as promptly as possible and shall inform the parties of the decisions. In deciding the protest the track official may take whatever action deemed appropriate to further the interest of fairness and finality in competition results. Such actions includes, but is not limited to, revising the official race results, imposing penalties, disqualifications, suspension, monitory fine,
subtracting points or takes no action. Matters not subject to protest: No protest will be accepted that is directed to a decision of a track official or supervisory official on any subject.
*Any payoff that is not collected within 3 weeks will be forfeited and will be returned back to the tracks general fund.
ANY AND ALL FUEL THAT TEST CLOUDY AND DOES NOT SMELL PROPER WILL BE DEEMED ILLEGAL AND NOT PERMITTED TO RUN! THE BASE FUEL USED FOR OUR TESTING WILL BE THE SUNOCO TRACK FUEL.
SUNOCO gas and alcohol is the mandatory fuel to be used for the 2017 season.
New for 2016: No roller bearing crankshafts.
New for 2017:
-Not Responsible For Typographical Errors