- MINIMUM TUBING SIZE AND THICKNESS
- All of the following are subject to inspection.
- BOTTOM RAILS: Must be minimum 1 3/8" diameter x .095 thickness or 1" diameter x .083 thickness.
- BRACE: Must be minimum 1" diameter x .065 thickness.
- REAR END SAFETY BAR: Rear safety bar is a mandatory piece. Must be a minimum of 1" diameter x .083 thickness.
- ROLL CAGE TOP CROSS MEMBERS: Must be a minimum 1" diameter x .095 thickness.
- ROLL CAGE UPRIGHTS: Must be a minimum 1 3/8" diameter x .083 thickness.
- TOP RAILS: Must be a minimum 1" diameter x .095 thickness
- UPPER RAILS: Must be minimum 1 3/8" diameter x .083 thickness.
- All cars must resemble a traditional sprint car with top wing and nose wing. Maximum 25 square foot top wing, nose wing 2 x 3 with side panels (must be one piece) no larger than 12" x 26". Center foil must be one piece and no wider than 60", with maximum sideboard 30"x72". No kick outs. Maximum 3" wicker bill. No split wings or bi-wings are allowed. Top wing must not extend beyond outside of rear tires. Maximum dish 2". No turnouts or any other foils allowed. Two stationary foils or rudders will be allowed to run the entire length of the underneath portion of top wing. Maximum height proportions are 1" at the front and 3" at the rear. Nowhere shall the foil exceed 3" in height. Leading edge of nose wing must be 20" from leading edge of front axle.
- Drag links and tie rods must utilize 4130 steel of at least 1.125" outside diameter and .058-wall thickness. Heim ends for both parts must be made of steel only. A magnet must stick at all times. No wedging of the tubing will be allowed.
- Drilling of any bolts, fasteners or heims ends is prohibited.
- No carbon fiber or composite materials allowed.
- No filing of frame rails, nerf bars or bumpers. No solid steel nerf bars or bumpers.
- No part of the car can extend past front bumper, with bumper no more than 23" from front and rear axle. No body pieces to extend beyond or underneath front torsion tube except hood.
- No pieces may be added to the basic fame so as to resemble, imitate, or be specifically designed to deflect, trap, or form a windbreak of any nature, except those used to cool or protect the motor and breaking system.
- No wedges or foils underneath race car.
- The drivers right side opening must be a minimum 10" vertical opening at any point and a minimum 21" horizontal opening at any point. Body panels or sheet metal may extend reward to triangular bar at back of roll cage and may extend downward past shock mount to horizontal bar at driver's compartment. No gurney lips or turnouts are allowed on any body panels. Bottom frame rails behind driver's seat cannot be enclosed. Hoods may be a multiple piece design, but must appear to be one continuous piece.
- Titanium brake controls are allowed. Titanium is NOT allowed on chassis construction, front and rear axles, steering arms, torsion arms, bumpers or nerf bars.
- DRIVE LINE
- Drive line hoop or strap is mandatory.
- Drive line hoop should be steel and welded or bolted in.
- Has to be center line of chassis.
- Must be completely enclosed.
- Open engine rule, 410 max.
- FRONT AXLES
- Minimum sizes 2" x .156 or 2" x .120 or 2 3/8" x .095 0r 2" x .095
- Must be steel only.
- Fuel bladders, are mandatory.
- No blowers.
- No nitrous oxide (NOS).
- No smaller than 24-gallon fuel tank allowed at anytime (27 gallon or larger fuel tank recommended).
- No turbo chargers.
- MANDATORY SAFETY EQUIPMENT
- 5 point harness must have manufactured tag with date not to exceed 3 years old. Belts must be installed to manufacturer's specifications.
- All cars must have aluminum racing seat and attached directly to roll cage.
- All cars must run a window net on driver's side that latches at the top is mandatory.
- An operational 2 and a half pound minimum fire extinguisher with gauge visible for inspection purpose is mandatory.
- Arm restraints.
- Drag link safety strap.
- Flame retardant diver suit. Must be minimum of 2 layers
- Flame retardant racing gloves.
- Flame retardant shoes.
- Head rest padding.
- Inside of roll cage must have protection padding where head can make contact.
- Mandatory 1/8 inch steel plate for drivers door.
- Right head net or support, head net equipped with a quick release capability
- SNELL SA 2000 approved helmet with sticker no more than 8 years old. (In 2010 sticker must be dated after 2002)
- Some type of neck restraint device must be worn at all time on the track. Neck collar, Hans devise, D-cell or G-force.
- NEW OR EXPERIMENTAL
- Anything new or experimental must be approved by Butler Speedway Officials in advance of race date.
- REAR BUMBERS
- Minimum 1" diameter, .065 thickness.
- Must be steel or stainless only.
- Nerf bars are mandatory and must be steel or stainless steel only.
- TRACTION CONTROL
- The penalty for having traction control will be loss of money and points for the night.
- Traction control devices are strictly prohibited.
- Car and driver are weighed as one unit, with driver seated inside the car.
- Car with driver cannot weigh less than 1375 pounds at the end of feature.
- If found light your car and driver will forfeit all points and money for all of that nights racing events and be disqualified from any finish.
- If weight is lost during a race, the car will be black-flagged.
- It is your responsibility to remove mud before any weigh-in.
- Track scales govern all cars!!!
- Weight, if added must be bolted to mainframe and have car number on it.