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305 Sprint car Rules

Along with the 16-inch medium Hoosier, the H15, H20, and the W18 will be allowed for use.

Mufflers Required. Options include the existing Schoenfeld #112535 or the new #14272735-78 muffler in 2013 or the Flowmaster 14-inch #53545-10.

The following specifications have been prepared by Fremont Speedway and Attica Raceway Park as guidelines for the construction of the 305-Sprint Division. No warranty of safety is expressed or implied as a result of this publication of rules. These rules are intended as guide and are in no way guarantee against injury or death to participants, spectators, or others. Anything not covered by these specifications should be approved by the track officials and placed in writing. Continuous developments in auto racing and technology may mandate changes in these specifications. However, it is our intent to enforce and police these rules throughout the season. If a change is necessary, technical bulletins will be prepared and distributed in advance.

This division was developed for the fun of racing in a low cost fashion. This requires limits in various areas to keep competition equal and fair for all participants. In order to accomplish this, if it doesn’t say you can – don’t! With the help and consideration of the participants, this can be accomplished. Try to live within the spirit of the rules. If you have questions, please contact track officials before you are found illegal for competition.

Weight Rule

• Starting in 2019 – 1,500 pounds including the driver. Top 3 in A-Main must go to scales

Failure to report to scales or meet minimum weight will result in disqualification.

• The only titanium that is allowed is the in the rear end.

• Track officials have the final say in determining the eligibility of each participant.


1. All engines must be GM 305cid V8s. RaceSaver engines are also legal. The block must be stock production type with maximum 3.805 inch maximum bore (316 cid maximum). Dart and Bowtie Blocks will be allowed using the same maximum bore of 3.805 inch. Engine must have all casting numbers for identification purposes. The block must be completely stock appearing (no grinding) on the outside. All engines must have flat-top pistons. I or H beam style rods can be used. Polishing of the sides of the rod I-beam permitted. Pistons may not protrude out of the block. Crankshafts may be stock GM 305 cast iron shaft with 3.480 inch maximum stroke or the Callies compstar crank and this can also be used as it comes out of the box no lightning other than to balance.

2. Cylinder heads must be Brodix Spec or All-Pro Aluminum

Brodix spec head requirements are: P/N: SP ST (bare) or SP ST PKG (complete).

Both P/N’s are the same casting (casting marks and stampings). Head must remain as cast. No porting or polishing of any kind in the intake or exhaust ports, under or behind the valves. No port matching. Do not disturb the combustion chamber. Brodix stamps must be seen. Must pass a 11:1 compression ratio this will be checked with a whistler.

ALL PRO spec head requirements are: To be 305 spec ALL PRO Head must be remain as cast. The same rules apply as those of the Brodix head. All Pro head will have marks in the ports similar to the Brodix. These heads must also pass the whistler at 11:1 ratio.

3. Valve springs must be straight and stock diameter of 1.26 inches. Stud mounted roller rocker allowed. No shaft mounted systems. No stud girdles. No rev kits. Screw in studs and push rod guides plates allowed.

4. Any ignition may be used.

5. Only stock diameter (0.842 inch) Flat tappet or Hydraulic lifters may be used NO ROLLERS OF ANY KIND

6. The oil system must be a wet sump system. No dry sump systems will be allowed.

7. Maximum fuel injection size permitted is 2 3/16 with all fuel lines in the manifold. No down nozzles allowed. Only one nozzle per cylinder. No carburetors or carburetor-style injections allowed. Stacks must be removable for technical inspection.

Track Officials will have the right to check engines at any time and will have the final say in determining the eligibility of any engine. Any illegal engine parts will confiscated until end of season.

Fuel and Fuel Pumps

1. Only straight alcohol (methanol) allowed. No gasoline, nitro, or nitrous systems. An approved fuel bladder is mandatory. Fuel system infractions mandate immediate disqualification.

2. No electric fuel pumps.

Wheels and Tires

1. All wheels may be steel or Aluminum.

2. Any steel wheel is permitted with the approval of Track Officials.

3. All right-rear wheels must have a bead-lock system with a tubeless tire. These are subject to approval.

4. Bleeders are allowed

5. Along with the 16-inch medium Hoosier, the H15, H20, and the W18 will be allowed for use.

6. All tires must be available to everyone.


1. All brakes must be in good working order at all times.

2. Failure upon inspection mandate disqualification.

3. No carbon fiber parts will be allowed.


1. A top wing is mandatory. The wings must be a minimum of 15 sq. ft and a maximum size of 25 sq. ft. (Note, the 25 sq. ft. maximum size is consistent with both the “All Stars” and “World of Outlaws”.) Dished or Flat wings allowed

Dished wing no wicker bill, flat wing 2″ maximum wicker bill. 

2. 30 in x 70 in will be the maximum area allowed for sideboards. Max wing width will be 61 inches.

3. No wing adjustments from the cockpit will be allowed. No hydraulic cylinders or valves, no levers or cables for adjustments will be allowed.

4. Number must appear on both sides of the wing in sizes suitable for scoring purposes. Numbers must be 16 inches tall.

5. Front wings or nose wing will be allowed. If a front wing is used, the maximum size is 6 sq. ft. Leading edge of nose wing must be within 20” of leading edge of front axle.

Body, Frame and Bumpers

1. Frame and body must be sprint car appearing and must be inspected to be deemed safe for competition by Track Officials.

2. Front and rear bumpers are required. Any bent or broken bumpers not meeting the approval of Track Officials must be replaced. No aluminum or titanium bolts allowed anywhere on the car. No carbon fiber or titanium parts will be allowed. All bolts must pass a magnet test.

3. Nerf bars, right and left are required.

4. No rubber stretch straps or bungie cords.

5. No black pipe fittings.

6. No nut will have any internal threads visible. The bolt should be at least flush with the nut.

7. Workmanship, safety, and appearance shall determine whether or not a car will be allowed to compete.

Axles, Drivelines, Steering

1. Front spindles may be steel or aluminum.

2. Any torque tube will be permitted. A torque tube safety hoop is required. No straps.

3. No torque arms or open drivelines allowed.

4. Only approved racing steering boxes – Power or Manual.

5. No cockpit adjustments of any kind allowed. ( weight-jackers, shocks, wing sliders,…etc.)


1. Aluminum racing seat required – Full Containment Seats Highly Recommended

2. Five point seat belts required. Belts cannot be over 2 years old.

3. Helmet – Snell 2010 or newer HIGHLY Recommended.

4. Flame retardant driving suit required.

5. Flame retardant driving gloves required.

6. Flame retardant driving shoes required.

7. Fire proof underwear and socks recommended.

8. Arm restraints recommended.

9. Roll bar padding, headrest and rock screen recommended.

10. Side head restraints recommended – Head and neck restraints Highly Recommended

Tethers and kingpins not required for weekly events.

Technical Procedures and Penalties

1. Any car may be inspected after an event by Track Officials. If a car is found to be illegal during technical inspection after event, the illegal car will lose its finish position, all points, and money for that event.

2. Upon the occurrence of the second infraction, all points earned for the year up to date will be forfeited as well as the points and money for that event. The owner/driver and car will be suspended for four dates of competition. This suspension can be carried over to the following season.

3. Track officials will have the final say in determining the validity of a protest or rules infraction.

4. Transponders required

5. Raceceiver radios required

6. Track officials have the right to ask for the removal any decal or signage deemed to be disrespectful, inappropriate, or offensive.

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