MINI STOCK RULES
Blythe Speedway reserves the right to alter or amend the rules and regulations in the interest of safety, cost control, and /or fair competition. It is the responsibility of each competitor to read and understand the contents of these rules. If there is a disagreement or dispute regarding the meaning or application of these rules, the decision of Blythe Speedway Race Director will prevail. Any interruption or deviation of these rules is left to the discretion of the Race Director and the decision is final.
COMPETING MODELS AND BODIES
Any 1970 or newer American or Foreign 2 or 4 door hardtop car produced with a minimum 90” wheel base. No jeeps or high-performance models. Any 2-wheel drive, 3 or 4 cylinder or 2 rotor engines. Front or rear wheel drive. No rear or midengine model cars. All cars must maintain stock OEM body for year, make and model. Fiberglass, steel or aluminum complete stock appearing bodies are approved. No Carbon fiber, Kevlar or titanium parts. Roof must remain stock and out of stock material. Hood and deck lid pins required. Full stock steel floorboards and firewalls required in stock location. Rear trunk area may remain open. 4” x 50” rear spoiler.
Stock or fabricated bumpers are required. Front and rear bumper must be fastened to the fender and or quarter panel and must be safety chained to prevent falling onto racing surface.
A windshield made of Lexan may be used. Minimum thickness is 1/8”. Windshields must be supported between the dash bar and the roof halo bar with a minimum of two (2) evenly placed metal straps 1/8” by 1” or a single 1.5” bar in the center of the windshield welded to the dash bar and the roof halo bar. Wire mesh screen is allowed. No back window allowed; rear side Lexan windows permitted. Driver side window net is required on all cars. Net material must be minimum 1” wide and have openings of at least 1”. Net must be equipped with a quickrelease device on the top left corner. Rearview mirror is mandatory, a driver side mirror is ok but cannot extend past body.
Full NASCAR type roll cages mandatory. Bars must be a minimum of 1 ½” O.D. x .090” wall thickness, gusset as necessary for strength. Minimum of three (3) door bars required on both sides. Right side can be straight. Engine must remain in the stock location. Fuel cell protector required, no more that the width of the frame rails. Main roll cage uprights must be fastened to floor of uni-body cars with a minimum 3/16” thick plate, top and bottom, at all four corners. Plate must be a minimum of 4” square, with four (4) 3/8” grade 8 bolts at each location. Roll bar padding must be used at any point where driver may make contact. Driver door must be padded. Door bars must be covered with 1/16” thick steel metal plate, top to bottom, from Blythe Speedway Mini Stock Rules Page 2 of 5 03.10.23 front and rear uprights, welded to outside of bars. Stock frames only for year make and model. No modifications allowed.
WEIGHT, WIDTH AND WHEELBASE
Minimum weight 2200lbs and maximum 57% left side weight at anytime. Minimum wheelbase 90” must remain as factory produced. Maximum overall width (front or rear) shall not exceed 62.5” from inside wheel to outside of wheel. Front tire width will be measured at spindle height. All lead must be securely fastened to frame using two (2) grade 8, 1/2” bolts. All lead must be painted white and have car number printed on it. Weight cannot be mounted further back than rear axle and not further forward than firewall. Any lost lead will be subject to fine of a minimum $10 per lb lost.
The engine must be stock for year make and model. No turbo or supercharger. No titanium parts. Steel rods only. Stock length rods ok. Only 5.7 aftermarket rods produced by Manley or Esslinger allowed. Stock fuel injection add 50 lbs. 10.0 to 1 max compression ratio. Engine oil coolers allowed. No dry sump oiling. Oil pan must have a minimum 1” inspection plug inline with #2 rod. Aftermarket oil pans, valve covers, water pump, fan pullies are allowed. No “stroker” or lightweight cranks allowed, factory OEM unmodified cranks only. Heads: Stock heads only. A stock head will be characterized as a cylinder head which was offered as standard equipment with no performance advantage. Stock for year, make and model 2 plug head add 50 lbs. No special performance options will be allowed, including but not limited to, oversize valves, special cut valves, relocated intake or exhaust bowls or ports. Stainless steel valves approved. No porting or polishing will be allowed. No roller rockers on the valve, side or cam side permitted. Maximum cam lift is .480” measured at the valve. No billet camshafts. Cast iron camshafts only 2500 cc maximum plus maximum overbore .060”. Engine Blocks: Stock blocks only. No modifications allowed. Stock stroke for engine being used. No Teflon coated parts. Stock lifters only. Solid lifters permitted. Stock type timing chain or belt only. No gear drives allowed. No crank lightening or grinding allowed. No after market lightweight cranks allowed. No titanium parts allowed.
Stock Holley list 7448, 350 cfm carb only. Must remove choke butterfly plate, shaft and linkage. No other modifications allowed. 2 carburetor return springs required must be mounted to engine block. Any unmodified OEM intake manifold allowed, no turbo intakes, and maximum 1” thick carb spacer or adapter. No vacuum leaks. 8. AIR CLEANERS AND FILTERS – No cold air induction allowed; K&N air filters are allowed. No air deflector allowed on front. Air filters only. Top and bottom of air cleaner must be solid and same diameter. Tubes, funnels, or any device which may control the flow of air, will not be permitted inside the air cleaner or between filter housing and carburetor.
All mounts be securely bolted; adjustable mounts are not permitted.
Stock ignition only. No performance after market distributors, components, or magnetos allowed. No msd, or dui components allowed. No traction control. All cars must be equipped with a master electrical switch located in the cockpit of the car. The Blythe Speedway Mini Stock Rules Page 3 of 5 03.10.23 switch must be within reach of the driver and safety crew form the left side of the car, switch must shut off car. Batteries must be securely mounted within the confines of the body and behind the driver, in front of the rear axle and contained in electrically insulated container. No marine or plastic type boxes allowed.
ENGINE COOLING SYSTEM
Stock or electric fans are permitted and must have shroud. Water overflow catch can unit required. One (1) quart minimum, vented out to windshield, metal or plastic, mounted in engine compartment. No anti-freeze or similar products. This is a finable offense. Water Wetter ok. Any radiator in the stock location.
ENGINE EXHAUST SYSTEMS
Any Stock OEM cast exhaust manifold, steel or stainless-steel headers are approved. No aluminum or coated headers. An approved muffler is mandatory, must not exceed 95 dB at 100 feet. Exhaust must extend past driver’s compartment and remain under car. Exhaust may exit on passenger side of race car in front of right rear tire. 3” maximum exhaust pipe.
Stock type clutch and flywheel for model being used only. No lightweight cheater parts. Clutch disc must contain all magnetic steel parts. Stock steel OEM or after-market steel billet flywheel. Aluminum flywheels are not allowed. Minimum weight of the flywheel is 16 pounds. Steel scatter shield mandatory. Track scales will be official. Stock type transmission only. No modifications. All gears must be operable including reserve. OEM rear end differentials or spools only. No lockers. Rear end must be centered in car. Steel Floater type rear ends are permitted. No hollow axles. No quick-change rear ends. Any OEM steel rear end allowed. Must be mounted exactly as old rear end that was removed, may be used in any MFR line. 2 driveline straps, 1” x 1/8” required, mounting to be within 6” of the U-Joints are required on rear drive vehicles. Steel Drive shaft must be painted white and have car number for on track visibility in the event it should become separated from the car. No cambered or toe in rear ends. Cars with independent rear suspension call for approved modifications. No 9” rear ends.
SUSPENSION AND BRAKES
Stock OEM lower control arms for make and model, no modifications allowed. Stock OEM upper control arm for make and model, no modifications allowed. Any OEM factory production type of balljoint may be used. No “Mono Ball” ball joints. Upper ball joints may be moved to adjust camber and eliminate binds. Stock steel unmodified OEM spindles for make and model. No heim joints. Stock type bushings. Stock OEM for make and model steering components. Stock or stock type replacement steering rack permitted. Racing springs ok. Lowering blocks allowed. Sliders blocks approved. No coilovers unless stock production for your year make and model. All other suspension components must be of original design and origin for the chassis used. No after market look alike parts to widen suspension. Any steel non-adjustable, non-rebuildable, factory sealed (welded) shock that fits the stock mounts may be used. Shock ends must be the same as OEM shocks. No heim joint or tic rod ends. No remote shocks. No spacing shocks up or down. Stock mount only. One threaded weight jack bolt may be used for each spring aligned with the coil. After market pedal and master cylinder assemblies allowed. Rear disc brakes allowed. Stock steel calipers. All components must be steel. No light weight parts. Stock make and model brakes. 4-wheel hydraulic brakes required, Blythe Speedway Mini Stock Rules Page 4 of 5 03.10.23 and all must be in good working order. One adjustable brake bias valve allowed. Any steel 1 piece sway bar mounted in the stock position. Mounted with rubber or urethane bushings. Outer may be adjustable. No heim joints allowed on the sway bar. No moving of suspension mounting points front of rear. If car has crash damage and has been repaired, the mounting points must be to the stock specifications. Rear upper shock location may be moved to accommodate the lowering of the car. No travel limiters or bump stops of any kind.
Stock steel OEM for make and model steering components only. Quick release steering wheels are recommended. Steering column must be collapsible. U joints are acceptable. 16. FUEL SYSTEM – Pump fuel ok or track race fuel ok. No additives, octane boost, or methanol. No cheater fuel of any kind. If OEM gas tank is ahead of the rear axle, a shield must be installed under it. If the OEM gas tank is behind the rear axle, it must be replaced with an approved racing fuel cell and securely mounted in the trunk area as far forward as possible. Minimum 8” ground clearance. Fuel cell must be mounted with steel framework (1” x 1”, .065” minimum) and must have a vent hose and the hose must have a check valve in the end. Fuel cell must be totally enclosed in an 18-gauge steel box with a ½” drain hole in the lower right rear corner. Ground strap required from fill neck to frame. Tethered cap. Maximum fuel capacity 22 gallons. If the fuel line runs through the drivers compartment it must pass through a metal tube sealed at both ends and brightly marked “do not cut fuel line”. Must have fuel cell protection bar. Electric pumps permitted, must have oil pressure shut-off installed. 17. TIRES AND WHEELS – Steel wheels are mandatory, DOT tire maximum 8” width x maximum 15”, any offset, but offset must match all four wheels. Tire and wheel must stay inside of fender and quarter panel. Stock type after-market long wheel studs allowed and recommended. All studs must have threads showing through the lug nut. No Bleeders. Wheel spacers and wheel adapters allowed.
SEATS AND SAFETY EQUIPMENT
For all safety equipment. It will be the sole responsibility of the driver, not Blythe Speedway, their agents/officials or corporate officers to ensure that his/her safety equipment is correctly installed, maintained, and properly used. Please refer to manufacturer installation and usage guide lines and adhere to them. Aluminum professionally built high back racing seat required. No plastic, etc. Padded headrest required. Seat must be securely bolted to a mount assembly that is an integral part of the roll cage. 6 bolts minimum no smaller than 3/8” diameter bolts. A five (5) point safety harness, with quick release is mandatory. 3” wide lap belt, 2” or 3” shoulder belts, and a 2” submarine belt. All belts shall be attached to roll cage using minimum 3/8 grade 8 hardware. Loop around belts ok. Cotton harness components prohibited. Safety harnesses/seat belts may be no more then three (3) years old. Must have manufacture date. Snell SA2010 or SA2015 helmet required. Full face helmets with Lexan face shield required. Nomex helmet, skirt and Nomex covered chinstrap highly recommended. A HANS or Hutchens type head and neck restraint device is strongly recommended; minimum of a neck roll required. Window net mandatory. Minimum 1” webbing Blythe Speedway Mini Stock Rules Page 5 of 5 03.10.23 with release at top only. It is required that all window net releases be updated to the quick release seat belt type with releases located and facing the outside of the car. No close mesh off road type allowed. Fire suit mandatory at all times. Two layer one piece suit recommended. Two piece suite ok. Single layer proban suit ok with Nomex underwear. Approved racing gloves mandatory. No welding gloves, gardening gloves, etc. Approved racing shoes mandatory. Eye protection is mandatory and must be in proper place at all times. Current test date (2 pound minimum) fire extinguisher to be installed in the car within drivers reach while strapped in. Steel mounts only, no plastic. All cars will be required to have in their pits a minimum of one five pound, Halon or dry chemical fire extinguisher. This is to be visible to tech officials and all crewmembers. All crew members must be made aware of this location, and knowledgeable in the use of the fire extinguisher. Car and driver will be required to make safety rule violations comply PRIOR to racing any event. The use of a two-way radio with spotter and/or pit crew is required. 19.
APPEARANCE AND IDENTIFICATION
All cars are to be neatly and brightly painted. Numbers will be a minimum of 18” on the roof and both door panels. Numbers on the roof to face toward scoring tower (flag stand). Numbers assigned to car will be displayed on the top right front of windshield, 3” minimum. No duplication of numbers. Advertising or names on the windshield is not permitted. This will be reserved for division sponsor. Advertising that is deemed to be unsuitable/offensive, will not be allowed. Decision of Blythe Speedway Tech Director will be official Division sponsor decals, if any, must be placed on designated location of car to be eligible for awards. This is to be completed PRIOR to competing in any event. 20.
The use of a two-way radio for communication with spotter and driver mandatory. Spotter must be on spotter stand with proper identification.
No electronics monitoring computer devices capable of storing or transmitting information except tachometers. No electronic traction control devices allowed. Transponders are required. Must be mounted on the right rear frame rail 12” behind the rear axle.
All rules are subject to change at anytime if deemed necessary to ensure even competition within the division.