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Mid Michigan Raceway Park

Late Model Rules*

2017 Schedule of Events
2017 Special Events
Test & Tune 2017
Kids Night 2017 / MARFC
Racers Memorial
2017 Corn Harvest
Late Model Rules*
Modified Rules*
Street Stock Rules
Mini-Stock 4 Cylinder Rules*
Pro-Stock / Pro-Truck Rules*
General Rules/FAQ
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Mid Michigan Raceway Park

Late Model Rules

2017 Season

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 events, and by participating in these events, all participants are deemed to have complied with these rules. NO EXPRESSED OR IMPLIED WARRANTY OF SAFETY 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 a participant, spectator or official.

The race director shall be empowered to permit reasonable and appropriate deviation from any of the specifications herein or impose any further restrictions that in his opinion do not alter the minimum acceptable requirements. NO EXPRESSED OR IMPLIED WARRANTY OF SAFETY SHALL RESULT FROM SUCH ALTERATION OF SPECIFICATIONS. Any interpretation or deviation of these rules is left to the discretion of the officials. Their decision is final.


Only conventional type V-8 engines with the cam in the block will be permitted. There will be no limit on the cubic inch displacement. All engines must be based on a manufactured, factory design. Aluminum or steel blocks will be permitted. All engines must be normally aspirated with a single conventional-type four (4) barrel carburetor. The engine must have an operating self-starting mechanism. Vehicles that require a ‘push start’ will not be permitted. Only a single distributor and magneto will be permitted. Coil pack and/or engines that have individual ignition systems, electronic or mechanical for each cylinder will not be permitted. A maximum of 25 ”-inches from the center of the ball joint to the front of the motor plate/engine bell housing flange will be permitted. Only two (2) valves and one (1) spark plug will be permitted per cylinder (1).


Direct drives systems of any-type will not be permitted. The transmission must be bolted to the engine it must have forward and working reverse gear(s) and must be able to shift to forward or reverse with engine running. All cars must be equipped with a working self-starter. The driveshaft must be a minimum of 2”-inches in diameter (1). All drive shafts must be painted white (2). Only one (1) drive shaft connected from the transmission to the center section of the rear end will be permitted. A minimum of one (1) driveshaft hoop / sling must be fastened securely to the frame. It is recommended that two (2) driveshaft hoops / slings be used. Any type of rear end differential / center section will be permitted. Live-axle type rear ends will not be permitted. Independent rear suspensions will not be permitted. Floater-type widefive hub assemblies will be the only hub assemblies permitted (1). All cars must have loop in place (1), if installed correctly (2).


All cars must have fuel cells that meet and/or exceed FT3 specifications. The fuel cell may have a maximum capacity of 35 gallons. The fuel cell must be enclosed completely in a container that is a minimum thickness of 20-guage magnetic steel and/or .060”-inch aluminum. The entire container must be visible for ease of inspection. The fuel cell must be mounted behind the rear axle between the rear tires, a minimum of 4”-inches ahead of the rear bumper. The bottom of the fuel cell must not be any lower than the bottom of the rear end/quick change housing. The fuel cell must be mounted with a minimum of two (2) .125”-inch thick steel straps. The straps must cover the entire cell. Fuel cells that are mounted in a square tubing frame will be permitted (1). A minimum of 7/16”-inch ASTM Grade 8 bolts must be used to mount the fuel cell to the frame. The fuel pick up must be positioned on the top or right side of the fuel cell and be constructed of steel. The fuel pick up must have a check valve (2). Only racing gasoline or alcohol will be permitted for competition. Nitrous oxide, nitro-methane and/or propylene oxide will not be permitted. For the purpose of inspection, the driver and/or crew must be prepared to drain fuel upon request for inspection and/or measurement. Only mechanical and/or belt driven fuel pumps will be permitted. Fuel injection system(s) and/or electrical fuel pumps and/or any type of pressurized fuel system will not be permitted (1).

A fuel shut off valve is required on each car. “Fuel Shut Off” securely mounted and easily accessible. The Michigan Dirt Track Inspector has final decision on mounting of shut off valve.

See below page for fuel shut off options:

If running a ball valve: A fuel shut off ball valve is required to be within reach of driver and safety crew and to be mounted with the handle through the deck or firewall not to be mounted inside the cockpit. The valve and handle must be painted bright orange, and clearly labeled with “Fuel Shut Off” securely mounted and easily accessible.

If running an Oberg Valve: An Oberg Fuel Line Safety Valve is required to be installed under body/deck and behind firewalls, in the fuel line and per manufacture instructions; not to be mounted inside the cockpit. The valve must be securely mounted and easily accessible for inspection. Car must be clearly labeled with "Oberg Fuel Valve" composed of a vinyl sticker (1" stroke orange letters with a white 1/2" outline) sticker must contrast from body and graphics to be easily readable. Two stickers will be required; one on the deck where the ball valve would have been mounted and one on the fuel cell or on the trunk lid (2).


The exhaust flow must be parallel to the ground. Exhaust systems that direct the flow toward the ground will not be permitted. All exhaust systems/headers must end with a collector (1). Muffler is mandatory maximum of 98 decibels at 100 feet (3).


All electronic and/or computerized wheel spin and/or ignition retardation and/or acceleration limiting and/or traction control devices of any type will not be permitted. Adjustable ping control devices, dial a chip controls, timing controls and/or automated throttle controls will not be permitted. Adjustable restrictor plates will not be permitted. Remote control components of any-type will not be permitted. Radios and/or devices for transmitting voice and/or data will not be permitted. Data acquisition systems will not be permitted. All ignition system wires must be visible for inspection (1). …Approved cameras must be mounted above the deck - no suspension cameras allowed. …Highly recommended all additional ports or plugs on ignition box be securely taped to prohibit accessories getting plugged into them.

6. FRAME The wheel base minimum will be 103”-inches with a maximum wheel base of 105”-inches. All frames must be fabricated from magnetic steel with a minimum of 2”-inches x 2”-inches or approved rectangular magnetic steel with a minimum material thickness of .083”-inches. A minimum of 1.75” Outside Diameter magnetic steel tubing, 4130 Chrome Moly or DOM with a minimum material thickness of .083”-inches, will be permitted for frames that are fabricated from round tubing (1). Rear bumpers that are stubbed may only extend a maximum of 8”-inches beyond the frame. Any stubbed rear bumper that extends further than the maximum of 8”-inches must be formed and directed 8”-inches toward the front of the car. External rub rails will not be permitted. All cars must be equipped with a tow hook and/or strap for the purpose of towing (2). All battery supports and/or mounts must be secure and braced in two (2) horizontal positions and one (1) vertical position (2). Any frame built on or after January 1st, 2006, must have the builder’s unique serial number plate prominently attached to the left side roll cage upright. The plate must be welded in place. All characters on the plate must be a minimum of ”-inch in height and the serial number must not exceed 8 characters(2).

7. WEIGHT The total weight of the car with the driver will be: A minimum of 2,300 lbs as weighed on the track scales at the end of any race (3). Weights up to 50 lbs must be positively fastened by 2, -inch minimum, grade 5 bolts with a minimum of two (2) weight clamps. Threaded rods will not be permitted. All weights must be painted white and clearly labeled with the car number on it (2). Any weight(s) must be securely attached to the frame below the body decking. Any car that loses any weight/ballast during an event may be subject to a penalty (1). Weights attached to the rear bumper and/or outside the frame will not be permitted (2). Pellet-type and/or liquid-type weight/ballast will not be permitted. Driver operated weight adjustment, ‘weight jacking’ devices will not be permitted (1).

8. OVERALL APPEARANCE The car must be neat in appearance and must display the car number on the front nose and the rear fuel cell. The minimum height for the number will be 6”-inches. The car must have legible numbers on each side and on the roof a minimum of 18”-inches high, the driver’s last name must be placed in legible letters on passenger and driver doors or rocker panels (2).

9. BODY (SEE DIAGRAMS 1-5) The nosepiece must match the body style of the make and manufacturer of the car and be the same as the make and manufacturer of the motor (GM, Ford, Mopar). All cars must have a minimum half-inch (1/2”) and a maximum of one (1) -inch radius at the top of fenders, doors and quarter panels. Sharp edge(s) will not be permitted. The floor boards and firewall must completely cover the driver’s area with no openings (2). Fins and/or lips (1) or vortex generators (2) of any-type will not be permitted anywhere along the entire length of the car. The body line must be a smooth even line from front to rear. Wedge shape cars and/or body styles will not be permitted. “Belly pans” or any type of enclosure on the bottom of the car will not be permitted. A skid plate to protect the oil pan is permitted. A maximum 1/8” skid plate will be permitted. Wings and/or tunnels and/or any type of air deflection device will not be permitted underneath the body and/or chassis of the car (1). A maximum of one (1) stone deflector, for rear mounted oil pumps, oil filters, and for the main oil tank will be permitted. The deflector may be made of steel, aluminum, or heavy gauge wire. The cover may only be mounted near the unit it is designed to protect with a maximum size of 18” x18” and only mounted from the upper right frame rail to the lower right frame rail (2). Panels of any type under the rear deck running from the front to the rear of the car will not be permitted. Bodies that are non-approved will be assessed a weight penalty. The minimum weight penalty will be as follows; 25 lbs per inch of the infraction. Any style air cleaner scoop used must be positioned in front of/or around the air cleaner and must not exceed 1”-inch in height above any part of the air cleaner (3). Any type of flange and/or air deflection device and/or fin that is designed to direct airflow will not be permitted. Cockpit adjustable components with the exception of brake bias adjusters will not be permitted. Adjusters of any-type, including but not limited to adjustable shocks, hydraulic or pneumatic weight jacks, trackers, ignition boxes or similar adjustable components will not be permitted inside the cockpit of the car or within reach of the seated driver (1).

10. NOSEPIECE Only the following approved nosepieces may be used; MD3, Performance Bodies, 2009 Dominator, ARP, Five-Star MD3 type or Performance Bodies/Five Star MD3 2015. Approved nose assemblies must be installed per the manufactures instructions. All nose assemblies must meet the maximum/minimum dimensions, shall maintain manufacture appearance and not be altered. Front nose assemblies, not meeting the maximum/minimum dimensions, at the series discretion, may be permitted to compete as a “non conforming” nose with a minimum of 50 additional pounds mounted in front of the motor plate. At series discretion, degree on non-compliance may require additional weight and/or placement of penalty weight in front of radiator. All nosepieces must be made of molded type material. Two piece noses must be positively fastened together in the center. Spacers added to gain width will not be permitted. The nosepiece must be mounted in a manner that does not alter its original shape (1). The nose shall remain flat above the nose lip/wicker bill (2). Alterations and/or additions made to this area other than cooling holes will not be permitted(1). The nosepiece can extend a maximum of fifty-two inches (53”) from the center of the front hub to the farthest point extending forward. The nosepiece must display a headlight decal package. A one-race grace period, running contrasting color tape in the shape of a headlight will be permitted (2).

11. ROOF The roof length from front-to-back must be a minimum of 44”-inches with a maximum of 54” inches. The roof width from side-to-side must be a minimum of 48”-inches to a maximum of 52”-inches. The roof must be stock appearing and be mounted level to the body. The minimum height of the roof will be 45”-inches with a maximum height of 48”-inches.The roof must be mounted parallel to the body and near the center of the car as viewed from the front of the car. A maximum 1-1/2” roll, turned downward will be permitted along the front of edge of the roof. A maximum 1”-inch roll, turned downward, will be permitted along the rear edge of the roof. These modifications will be permitted to improve the strength of the roof. Any other modifications to the roof will not be permitted. Flat and/or odd shaped roofs will not be permitted. Bellied and hollowed roofs will not be permitted. Any sun/antiglare shields may not exceed a 4” drop from the top roof line, and must hinge for easy exiting. A maximum of two (2) roof edge bead rolls of a maximum height of ”-inch the length of the roof will be permitted. The roof posts and spoiler support(s) may not overlap. Only single plated roofs will be permitted. The maximum thickness of the roof at any point will be ”-inch. The roll cage and associated frame members above the interior panels (decking) must remain open. Enclosures will not be permitted (2). 5 2016 Michigan Dirt Late Model Rules 2016 Michigan Dirt Tracks. All Rights Reserved. Approved for racing at: Crystal Motor Speedway, I-96 Speedway and Tri-City Motor Speedway.

12. ROOF SUPPORTS AND WINDOW SIDE PANELS All roof side panels must extend to the edge of the body. The roof side panel window size must be a minimum of 10”-inches x 15”-inches and must match drawing number -2- side view. A maximum crown of two (2) inches will be permitted, measured from the center of a common tangent point on either side of the crown. The side window area may be covered with clear Lexan and/or equivalent type material, be cut out and/or represented by a decal. Both roof support openings must be covered and/or both must be left open. The left and right side openings must be the same size with a tolerance of one (1) inch. The left and right side window panels must match. A maximum bow of two ( 2”)-inches outward on the window side panels as viewed from behind will be permitted. The front roof supports up to 2”-inches in width must extend forward to the rear of the hood (2).

13. FRONT FENDERS, FENDER FLARES, AND HOOD The hood and the front fenders must be level and flat from the left to the right side of the car. The outside edges of the hood and/or the fender must remain inside the overall bodyline. The front fender may be a maximum of 37”-inches in height, measured vertically from the ground to the top of the fender behind the front tires. The front fender flares must be made of plastic and must not alter the original shape of the nose piece. The front fender flares must not extend beyond the front tires more than 1”-inch per side to a maximum width, edge-to-edge, of 90”-inches in width with the wheels pointed straight. The front fender flares must be flat across the entire width of the car. The front fender flares must have collapsible supports (2).

14. DOORS The door-to-door measurement must not exceed 76”-inches in width at the top of the doors. The door-to door measurement must not exceed 82”-inches in width when measured at the bottom of the doors in the center of the car. The doors must not exceed 37”-inches in height when measured from the ground to the top of the door. The door sides may not break inward from the top 76”-inches and bottom 82”-inch measurements. Hollow and/or belled doors will not be permitted. The minimum ground clearance will be 3”-inches (2).

15. QUARTER PANELS The maximum distance from the center of the rear hub to the top rear of the quarter panel is 52”-inches. The quarter panels must not exceed 76”-inches in width at any point as measured at the top of the panels. The rear deck must taper in a symmetrical manner from the center of the rear hub to the rear spoiler with a minimum width of 72”-inches and a maximum width of 76”-inches. The maximum width for the quarter panels measured from outside-to-outside measured 19”-inches from the ground and/or at the bottom of the quarter panel will be 86”-inches. Any breaks and/or bends formed in the sides of the quarter panel that move the panel toward the center of the car will not be permitted. Hollow and/or bellied panels will not be permitted. The maximum distance from the center of the rear hub to the rear trailing edge of the quarter panel will be 48”-inches. The maximum height from the ground to the top of the rear deck at the top of the rear quarter panel is 38”-inches. A minimum of 2”-inches of tire clearance between the tire and the body will be required. Skirting that extends behind the rear quarter panel will not be permitted (2).

16. SPOILER Only aluminum and/or Lexan and/or Lexan-type rear spoilers will be permitted. The maximum overall height of the rear spoiler will be 8”-inches. The maximum width of the rear spoiler, including braces and/or supports is 72”-inches. The rear spoiler must begin at the deck and extend 8”-inches from that point. Suspending the spoiler to create a wing-type device will not be permitted (1). The rear spoiler must begin at the rear most point of the quarter panels. Only three spoiler braces/supports will be permitted. The front edge of the spoiler brace/support must be in line with the spoiler. The outside spoiler supports must not be mounted any-wider than the top of the quarter panel(s) and must be centered on the rear deck. In the event that aluminum angle is used to bracer the upper edge of the spoiler, the angle must not add to the height and/or length of the spoiler in any way (2).

17. INTERIOR The interior of the cockpit must be a minimum of 11”-inches below the top of the roof and/or roll cage, measured perpendicular to the ground from the bottom of the roof to the cockpit deck. Roof rolls are not part of the measurement. The side window opening(s) must be 15”-inches from the top of the door to the bottom of the roof. Supports bars that block the right window from the driver exiting the cockpit will not be permitted (1). A single rock guard (Lexan screen) tapered back from the steering wheel to the height of 1”-inch in line with the driver’s chest providing the 11”-inch minimum clearance is met at any point from the roll cage to the body and/or rock guard. If the interior deck drops the drop must begin at the rear of the engine plate with a maximum of 4”-inches and must not drop below 4”-inches rear of the hood. The start of the dropped interior must remain closed as a part of the fire wall. The entire width must be closed off with sheet metal. The interior must gradually taper up to the quarter panel height and must be level for a minimum of 20”inches from the rear of the quarter panel and deck (2).

18. DRIVER COMPARTMENT A full metal firewall fabricated from magnetic steel and/or aluminum must encompass the driver’s compartment from front-to-rear, on both sides and floor boards (2). The driver’s seat must be a high back aluminum seat, designed specifically for racing, located on the left side of the car and mounted per the manufacturer’s instructions securely to the frame. The seat design should be one from a current manufacturer and/or recommended to include the full containment design. Installation of the full containment seat should follow the manufacturer’s instructions. All cars must be equipped with a quickrelease type steering wheel (1). The driver compartment must have a starting switch and/or button within reach of the driver. A clearly labeled electrical on/off ignition ‘kill’ switch must be to the right of the driver and within drivers reach (2). Mirrors of any-type will not be permitted. Radios and/or electronic and/or data communication devices will not be permitted (1). Any edge and/or sheet metal end in and around the driver compartment must be protected with trim and/or beading and rounded. Sharp and protruding edges will not be permitted (2). A substantial rock guard with a minimum of three (3) additional roll bars must be mounted in front of the driver (1). The rock guard must be made from wire screen. Windshield screens must be a minimum of .090-inches and must be securely fastened (2). A fully charged fire extinguisher meeting SFI 167.1 specifications, with activation push and/or pull knob, within reach of the driver is recommended (3).

19. BRAKES All cars must be equipped with an operating four wheel disc brake system (1). Brake lines must be visible for inspection (2).

20. SUSPENSION All shock absorbers must be constructed of magnetic steel and/or aluminum. Remote reservoirs will be permitted. Coil springs must be magnetic steel. Leaf springs may be composite material or magnetic steel (1).

21. ROLL CAGE All cars must have a roll cage fabricated from a minimum 1-1/2” outside diameter, .065”-inch thick seamless DOM magnetic steel tubing (1). The side roll bars and/or door bars must extend into the door panels (2). A minimum of thee (3) bars must be utilized on the left side of the car in the door area. Any of the bars that are utilized for the top portion of the roll cage, including, but not limited to the front and rear hoops, the top hoop and the uprights, must extend a minimum of 1”-inch above the driver’s helmet (1). All new frames and/or roll cages built on or after January 1st, 2006 an additional vertical side brace is required on the left side in vertical alignment with the steering wheel (2). …Requirements are mandatory for main cage, which consists of halo and for down bars. Tracks are supplied with a ‘go-no-go’ gauge to check this tubing. Gauge is strictly for a quick check - should tubing be questionable, use calipers for accurate measurement. …Cross bar may be installed side-to-side, front-to-back, or diagonally.

22. WHEELS Only steel or aluminum wheels will be permitted for competition. The wheels must be mounted to the hubs utilizing racing / safety lug nuts. “Knock off” and/or single type wheel mounting systems will not be permitted. The maximum wheel width that will be permitted is 14”-inches. The maximum front track width will be 90”-inches and the maximum rear track width will be 88”-inches, measured from the outside edge of the tire to the outside edge of the tire. Wheel spacers will be permitted provided the track width(s) do not exceed their maximum dimensions (1).

23. TIRES Only American Racer AR56 27.5/11.0-15DT, 28.5/11.0-15DT, & 29.0/11.0-15DT Tires, with the MRTW stamp, will be allowed for regular race nights. No other tires will be allowed on any corner of the car. (1) There will be a tire hoop used for inspection and the tire must pass through the tire hoop freely, without any manipulation or outside contact. Tires changes will not be permitted once a car has been presented to the starting grid/lineup area for any race. Any cars making a tire change will forfeit their assigned starting position for that particular race and start from the rear of the field. Chemical alterations, vulcanizing, tire softening, defacing and/or altering the face of the tire lettering and/or tire stamping will not be permitted. Chemicals or tire softening is not permitted at any time. Tires may be inspected at any time. Tires will be subject to a durometer test. Your tires must be harder that the baseline determined by MICHIGAN DIRT TRACK officials. Any violation with any tire presented for competition may result in immediate disqualification from the events and/or other penalties including but not limited to; loss of money, fine, loss of points and/or suspension. Only approved tires will be permitted for use in competition (1).

24. SAFETY EQUIPMENT Rules apply at all times car is on track. Snell-rated SA2005, SA2010 or SA2015 helmet required (1). Roll bar padding required in driver compartment (2). Recommended: Fire retardant padding. SFI-approved full fire suit required(1). Fire retardant gloves, shoes and neck brace (or head and neck restraint) required. Competitors under the age 18 are highly recommended to use an SFI 38.1 head and neck restraint system due to the young body and developing bones. Right and left seat head supports required if using head and neck restraint system. Recommended: Fire retardant head sock and underwear, collapsible steering shaft. Driver-side window net required, minimum 16 inch by 20 inch ribbon or mesh style (1), and must be mounted to roll cage so latch is at top front of window (2). Minimum three inch (two inch with head restraint system) wide SFI-approved five point safety belt assembly required (1), must be mounted securely to main roll cage. Recommended: Safety belts no more than two years old. Kill switch required within easy reach of driver and must be clearly marked ‘OFF’ and ‘ON’ (2). …M-, K- OR SA2000 rated helmets are not allowed. Rating sticker is located inside helmet liner. …Mechanics gloves are not fire retardant, must wear fire retardant gloves. …Roll bar padding must be on cage anywhere the driver can come into contact with it. …No Y-type shoulder harnesses allowed. Harness should not be mounted to tail section or tail section bracing. …Any driver voluntarily stopping during competition requiring assistance to restart goes to rear of field. If stopped by officials and assistance is needed, driver gets spot back.