Classes

Click on the class to view the details on the rules.

Engine 600cc 4 cylinder 4 stroke as comes on a stock production bike for public sale in the
U.S.A. No current year production engines.
Except as noted, all internal and external engine parts must remain stock with no
modifications, metal removal, blueprinting.
Valve seat inserts may be reworked. Valve springs may be shimmed with standard or
aftermarket shims.
Cylinder head combustion chambers may be cleaned by bead blasting with valves seated in
place.
Cylinder head gaskets may be replaced only with original equipment manufacturer’s stock
parts (All 3 layers of the head gasket must be used). All other gaskets may be replaced with
duplicate aftermarket parts.
Light cleaning of gasket surfaces with steel wool, Scotch-Brite, etc. is allowed.
Transmission gears may be shimmed only for the purpose of proper engagement. Standard or
aftermarket shims may be utilized.
Aftermarket cam chain tensioner allowed for safety of motor.
Fuel injection engines may run carburetors. Injected with power commander allowed gas or
alcohol. No timing modules allowed. Fuel injection engines running carburetors may change
all fuel metering devices to tune fuel curve, Billet intake boots allowed.
Modification of oil pan & pick up allow allowed or aftermarket ok.
Modification to thermostat cover allowed or aftermarket ok.
Modification to water pump cover allowed or aftermarket ok.
Any air box, stock appearing CDI, aftermarket washable replacement air filter, power
commander on fuel injection models only.
Any 600cc OEM CV carburetors (no flat slides allowed).
Fuel cell securely mounted. Tank used for qualifying heats must remain for all events.
No flammable liquids allowed in cooling systems.

Engine 600cc 4 cylinder 4 stroke as comes on a stock production bike for public sale in the
U.S.A. No current year production engines.
Except as noted, all internal and external engine parts must remain stock with no
modifications, metal removal, blueprinting.
Valve seat inserts may be reworked. Valve springs may be shimmed with standard or
aftermarket shims.
Cylinder head combustion chambers may be cleaned by bead blasting with valves seated in
place.
Cylinder head gaskets may be replaced only with original equipment manufacturer’s stock
parts (All 3 layers of the head gasket must be used). All other gaskets may be replaced with
duplicate aftermarket parts.
Light cleaning of gasket surfaces with steel wool, Scotch-Brite, etc. is allowed.
Transmission gears may be shimmed only for the purpose of proper engagement. Standard or
aftermarket shims may be utilized.
Aftermarket cam chain tensioner allowed for safety of motor.
Fuel injection engines may run carburetors. Injected with power commander allowed gas or
alcohol. No timing modules allowed. Fuel injection engines running carburetors may change
all fuel metering devices to tune fuel curve, Billet intake boots allowed.
Modification of oil pan & pick up allow allowed or aftermarket ok.
Modification to thermostat cover allowed or aftermarket ok.
Modification to water pump cover allowed or aftermarket ok.
Any air box, stock appearing CDI, aftermarket washable replacement air filter, power
commander on fuel injection models only.
Any 600cc OEM CV carburetors (no flat slides allowed).
Fuel cell securely mounted. Tank used for qualifying heats must remain for all events.
No flammable liquids allowed in cooling systems.

Engine 600cc 4 cylinder 4 stroke as comes on a stock production bike for public sale in the
U.S.A. No current year production engines. Except as noted, all internal and external engine parts must remain stock with no modifications, metal removal, blueprinting.

Valve seat inserts may be reworked. Valves must remain as produced with no modifications.

Valve springs may be shimmed with standard or aftermarket shims.

Cylinder head combustion chambers may be cleaned by bead blasting with valves seated in
place. Intake and exhaust ports may not be bead blasted.

Cylinder head gaskets may be replaced only with original equipment manufacturer’s stock
parts (All 3 layers of the head gasket must be used). All other gaskets may be replaced with
duplicate aftermarket parts.

Light cleaning of gasket surfaces with steel wool, Scotch-Brite, etc. is allowed.

Transmission gears may be shimmed only for the purpose of proper engagement. Standard or
aftermarket shims may be utilized. Aftermarket cam chain tensioner allowed for safety of
motor.

Fuel injection engines may run carburetors. Fuel injection engines running carburetors may
change all fuel metering devices to tune fuel curve, Billet intake boots allowed.
Modification of oil pan & pick up allowed or aftermarket ok.Modification to thermostat cover allowed or aftermarket ok.

Modification to water pump Cover allowed or aftermarket ok.

Any air box, stock appearing CDI, aftermarket washable replacement air filter.

Any 600cc OEM CV carburetors (no flat slides allowed).

Restrictor plate must have hole diameter .750 inside, outside must be tight against inside of
boot, absolutely no allowance, plate must be against carburetors. Restrictors must be flat, no
cones.

a.) Briggs World Formula - KSUSA Engine Rules (Rule #22)
b.) Age 6-12 (Rule #1)
c.) 400lb. Minimum Weight (Rule #8)
d.) Spec. RR tire (Rule #14)
e.) 6 sq. ft. Min. wing size (Rule #17)
f.) Fuel Bladders NOT Required, but STRONGLY RECOMMENDED!

1. Age. Drivers ages 6 through 12 (A driver whose 13th birthday falls during the racing season will be allowed to finish the season in which they began accruing points before their birthday.) may compete in the Junior Sprint Class. (exception drivers age 5 with prior racing experience that can prove they can safely handle the car can participate with the tracks approval and must start at the rear for a min. 3 weeks)

2. Roll cage. Roll cages shall be at least 1 inch .083 wall thickness mild steel, or 1 inch .065 wall thickness chromoly steel minimum. The front section of the cage shall be no further back than the steering wheel. Roll cage shall have sufficient fore and aft bracing and strength to support the weight of the car & driver in case of an upset. Bends must have at least 3 inch radius. No square or pointed corners allowed. Roll cage must be a minimum of 3" above the drivers helmet to the top of the cage at any point above the drivers helmet. It is mandatory to install a cross brace behind the seat to support the shoulder harness at a point not lower than 1 1/2 “ below or above the top of the drivers shoulders.

3. Bumpers and Nerfs. Car must have bumper extending beyond the front and rear tires. Nothing may extend beyond a tangent line from the outside edge of the tires to the bumpers. Nothing may extend beyond the outside edge or the tires or wheels, whichever is the widest. No sharp corners or design as to hook or damage. Front bumpers not parallel with front frame bar must be straightened or replaced. All cars must be equipped with nerfing bars. Nerfing bars must extend to inside edge of tires, but not beyond the outside of tire.

4. Safety. Seat belts must be securely attached to the car and used at all times. Metal to metal latches only. 5 point seat belts, shoulder harness and
   sub strap are required. Belt dates must not be over three years old. (Example: Oct 09 may be used in 2010, 2011 and 2012.) Arm restraints are mandatory and must be adequately adjusted to keep the drivers hands below the top of the roll cage. Helmets must be full head coverage competition type and one of the three latest SNELL approvals. Nomex head socks recommended. All drivers will wear a name brand flame-retardant uniform. Neck braces and\or cage nets with a SFI 3.2-1 rating or higher or Total Head containment seats are mandatory. SFI gloves are mandatory for safety.
   Total Containment Seats are strongly reccommended but are not mandatory.

5. Cockpit Controls. On and off switches must be on dash, top of the cowl or on steering wheel. On/off switch must be functional. No radio communication is allowed with the car or the driver. Cockpit controls: carb adjusters, kill switch, starter button and engine monitor. No wing sliders or pan hard adjusters driver operated in cockpits.

6. Battery. All wet cell batteries mounted in the cockpit must be covered and vented outside the cockpit area.

7. Fuel. "Junior Sprint" Class cars must run SUNOCO PURPLE or track approved fuel !. No Ethanol or other additives are allowed!

8. Weight. Minimum car and driver weight: 400 lbs.

9. Suspension. Aluminum or steel body shocks are legal. Torsion bars and coil overs are legal

10. Wheelbase; Maximum 52 inches. Minimum 50 inches, center of front axle to center of rear axle. Rear axle to be steel or splined aluminum 1 1/4" min dia.

11. Maximum Tread Width. not to exceed 55” outside of tire to outside of tire.

12. Steering; Front wheels must be connected by a solid or tubular aluminum or steel tie rod. Rear wheel drive only. All suspension bolts except wheel nuts must be secured by some type of locking device.

13. Brakes. Brakes will be of sufficient strength so as to slide the rear wheels while the car is in motion at any given time.

14. Tires and Wheels. Wheels to be 8" diameter steel, or aluminum Wheels must be held on with 3 or more standard lug nuts or knock-off hubs.

15. Bodies. All cars must have complete bodies of Sprint Car design only. Tail sections must be in place for time trials and all races. There must be a metal firewall between driver and engine, made of 24 gauge steel or .060" aluminum. Body of car must be made of aluminum, metal, fiberglass or high impact plastic. No rear view mirrors. The only part of the car allowed to be dismantled for driver to enter or exit is a quick release steering wheel hub. All mechanically operated devices must be mounted below the driver’s shoulders for safety.

16. Transmission. The drive will be by engine or jackshaft mounted clutches. No axle mounted clutches allowed. No direct drive will be allowed. Chain guards will be made of .090 inch thick aluminum or equivalent and will run on top of chain from the front of the front sprocket to the center of the rear axle. Driver must not be able to touch the chain or sprockets while sitting in the cockpit.

17. Wings. Right side board, maximum 42" x 20". Left side board, 42" x 20". Minimum size is 6 sq. ft. The wing cannot be mounted outside the centerline of the tires. No wood except for ribs or spars inside center section. Lower front corner of the wings sides cannot be more than 4" below top of roll cage. Nose wings cannot exceed 24"x 18", and must carry car number. Top wings are mandatory to enter a night's
    event.

18. Numbers. All cars must have legible numbers on both sides of car and the nose. Minimum height of numbers is 8" on the nose or nose wing, 10" on each side of the tail and 12" on the wing.

19. License. No license is required to enter a night’s event (Minimum age requirements must be met, Rule #1).

20. Ballast. Any material used for ballast must be firmly attached as a part of the car's structure. No liquid or loose ballast such as water, fuel, oil,
    sand bags, rocks, log chains etc. allowed.

21. Hubs. Front hubs minimum 3/4" bearings designed for racing. Rear hubs: Douglas 5 x 130 type or equivalent designed for a racing application.

22. Engine Rules. Briggs & Stratton World Formula engines as defined by the Jr Sprint USA. The Briggs World Formula will use a RLV 5442S header or stock pipe and RLV 4100 silencer as defined in the Jr Sprint USA Briggs World Formula rules. Stock pipes may be cut and turned as necessary to fit the race car as long as the pipe still retains the original length, diameters and volume as the original stock pipe.

All engines must be within the guidelines that are stated in the “Jr Sprint USA Briggs World Formula Rules
2012” .

Fuel:

• Fuel to be SUNOCO PURPLE with NO ADDITIVES. Fuel may be checked by any means against a common source. Each competitor is allowed one courtesy check of fuel in his tank with the method to be used at the event. Compliance with the common source will be determined by zeroing a Digitron gas meter in a sample of source fuel and allowing each competitor a deviation of +/- 5 points from zero and/or by any Digitron recommended method. Track approved fuels must pass same common source test.

Drivers must be a minimum of 13 years of age.

1. Roll Cage minimum size 1 ¼”, .095 4130 Chromoly Tubing. The front section of the cage shall be no further back than the steering wheel. Roll cage shall have sufficient fore and aft bracing, and strength to support the weight of the car and driver in case of an upset. Cage shall have gussets at the intersecting bars to the uprights. Bends must have at least 3 inch radius. No square or pointed corners allowed. Roll cage must be a minimum of 3 in. above the driver’s helmet.

2. Wheelbase shall be 64” to 74”.

3. Must be Chain Drive.

4. Chain guards mandatory. It must shield Driver from chain.

5. Must have sprint car style hood, tail and have the appearance of an open wheeled dirt sprint car. No modified styles or radical offsets.

6. Motor not to be offset more than 6” from chassis centerline. (No sidewinders)

7. All cars to be equipped with either a steering gear or rack and pinion.

8. A firewall between engine and driver is required.

1. Tire Rule: Right rear must be a Hoosier RD15, D15, SP2, SP3 or Ecotech.

2. 13” wheels only.

1. Only reciprocating piston engines allowed. No Turbo charging, supercharging or rotary engines allowed. Approved Lighting Sprint car engine is described as a production engine of which at least 100 engines of identical design and assembly have been manufactured and made available for sale.

2. 1205cc maximum displacement. No downsizing.

3. Original equipment manufacturer (OEM) crankshaft only, must be stock stroke.

4. No aftermarket cylinders.

5. No traction control allowed. If part of factory ECU, it must be disabled.

6. Aftermarket use and or modification of ignition, exhaust, carburation, and mechanical or electronic fuel injection allowed.

7. Transmission - must be operable in all gears.

8. Oil Pan and pickup modifications allowed.

9. Dry sump oil system allowed.

10. Must have operable on-board battery, starter and clutch.

11. Must have stock (working) charging system. No cut out allowed.

12. Methanol or Gas. No Nitrated fuels.

13. Mufflers mandatory. Tulsa Fairgrounds requires each vehicle’s noise level be below 95DB.

(Post race with driver)

Methanol: 1001-1205cc engines 1000 lbs.
1000cc or less engines 925 lbs.

Gas: 1001-1205cc engines 975 lbs.