Texoma Motor Speedway

2008 Modified 4 Rules
 

WHEELBASE AND WEIGHT

  1. Minimum wheelbase is 92” Maximum wheelbase is 102”
  2. Minimum weight after race with driver is 1700 lbs.

 

ROLL CAGE

  1. All cages must be 1-1/2” outside diameter x .095 wall steel tubing. (no welded corners )
  2. Driver’s head must be at least 2” below top of cage.
  3. All cars must have at least three (3) door bars on driver’s side of car. Door bars must be a minimum 1-1/2” x .095 wall steel tubing. Door bars must be sufficiently gusseted and tied to the car at the bottom. Cars must have at least one right side door bar that goes from front hoop to rear hoop diagonally.
  4. All cages must be a minimum of six (6) points.
  5. The frame may be 2 x 2 x .083 but he center section must be 2 x 2 x .120 or 2 x 3 x .083
  6. A minimum of three Ό” dia. Rods in windshield in front of driver are required.

 

BUMPERS

  1. Front bumpers must be centered on frame rails.
  2. Front bumpers may be 1-1/2” od, no more than 8” overall in height from top to bottom.
  3. Front bumpers can be no wider than 34”
  4. Rear bumper can be no more than 12” tall and may not extend back more than 6” from any body part.
  5. Rear bumpers that extend beyond 5” outside of mainframe rails must be bent back into frame and be welded.

 

NERF BARS

  1. Nerf bars must run in a horizontal direction and have rounded ends.
  2. Nerf bars must be welded or bolted to car.
  3. Nerf bars can be no wider than tires.
  4. 1-1/2” dia tubing or 1 x 2 rectangle only

 

ENGINE

  1. In line four-cylinder (carburetor type only) with a maximum displacement of 2450cc. Engines over 2450cc add 125 lbs, for a total weigh of 1825 lbs.
  2. Rear of engine must be at least 64” from centerline of the rear end housing.
  3. No rotary or turbo engines.
  4. No dual overhead cams.
  5. Engine must use stock block, head, distributor, and crankshaft.
  6. Must use stock intake. May be machined to receive carburetor only.
  7. Milling of head to increase compression allowed.
  8. No porting, polishing or port matching allowed. NO GRINDING INSIDE OR OUTSIDE OF PORTS.
  9. Carburetor must be un-altered Holley #4412 or 5200 series with a stock venture bore, stock throttle body, and stock booster location. May run stock OEM carburetor not to exceed 500cfm. No Weber or Mikuni carburetors.
  10. Battery type ignition in stock location only. No magnetos, dual points, MSD boxes, or any other aftermarket ignitions allowed.
  11. Any solid surface cam, valve springs, rockers, pistons, and lifters are allowed.
  12. Intake or exhaust valve size is not a tech item.
  13. Push rods are not a tech item.
  14. Stock exhaust or racing headers are allowed.
  15. Blocks must have engine numbers.
  16. Unless otherwise stated, only OEM production passenger car parts for engine are allowed. OEM parts must bolt on without modification.

 

DRIVE TRAIN

  1. Standard or automatic transmissions are allowed. Automatic transmissions must use OEM torque converter.
  2. All cars must have a scatter shield made of Ό” steel, 3” wide, that covers 180 degrees of top of bell housing. (Or approved blanket)
  3. Transmissions must have at least two (2) forward gears and one (1) reverse.
  4. Rear end must be locked.
  5. Rear ends must be stock type.
  6. Drive shafts may be altered or welded.
  7. Drive shafts must have a safety hoop 360 degrees around driveshaft 6” back from U joint.
  8. No dog clutches or multi-disc clutches.

 

SUSPENSION

  1. Front and rear suspension must be stock type, but may be modified.
  2. No welding springs solid. No wooden blocks in springs.
  3. One shock per wheel.
  4. Weight jacks allowed.
  5. Lower A-frames may be fabricated.
  6. No independent rear suspension.
  7. No one piece steering shafts.
  8. Upper A-frames may be tubular type. Heim joints are allowed.
  9. Coil-overs are permitted.

 

TIRES AND WHEELS

  1. 8” max steel wheels only. (Any offset) Rim centers must be completely welded and may be reinforced.
  2. ½” or larger Wheel studs are mandatory.
  3. D.O.T. tires or Hoosier oval track D.O.T. dirt tire 8” in width No mud or Knobbies tires allowed.
  4. Bead locks are allowed
  5. Tires may be ground or grooved. 

 

RADIATOR

  1. Only one (1) radiator is allowed and must be centered in front of car.

BATTERY

  1. One (1) 12 volt automotive battery allowed per car.
  2. The battery must be mounted to frame or cage and be in a marine type case.

 

FUEL AND FUEL TANK

  1. Fuel may be pump gas, racing gas, or alcohol. No additives.
  2. Racing fuel cell is required.
  3. Fuel cell must be vented and have ball type roll over valve.

 

BRAKES

  1. All cars must have a minimum of two (2) working rear brakes. Four-wheel brakes are recommended.

Rule Disclaimer: The rules and or regulations set forth herein are designed for the orderly conduct of racing events and to establish minimum acceptable requirements for such events. The rules shall govern all entrants. NO EXPRESS 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 deviations from any of the specifications, herein, or impose any further restriction, 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 deviations of these rules is left to the discretion of the officials. Their discretion is final.

January 1, 2008

Texoma Motor Speedway

Wichita Falls, Texas