Texas Thunder Speedway Rules

1. BODY:  ANY U.S. MANUFACTURED FULL BODY PASSENGER CAR, 1960 OR NEWER, 108” WHEEL BASE MINIMUM, FULL FRAME

OR UNIBODY. FRONT FIRE WALL WITH FLOOR PAN MUST BE IN STOCK LOCATION.  CAR BODY MUST APPEAR STOCK.   THE

MAX HOLE IN HOOD WILL BE 14” FOR AIRCLEANER. FRONT FENDER WELLS MAY BE REMOVED.   THE FUEL CELL, IF  LOWER 

THAN FRAME RAILS, NEED TO HAVE A REAR PROTECTION LOOP.  THE TRUNK LID, ROOF, AND HOOD MAY BE GUTTED.   ALL

BUMPERS MUST BE MOUNTED IN  THE ORIGINAL LOCATION, AND MAY NOT EXTEND PAST THE FRAME HORNS.  FRONT 

FENDERS MAY BE REMOVED.  ALL CHROME AND GLASS MUST BE REMOVED FROM THE BODY.  ALL HOLES AND FIREWALL 

MUST BE PATCHED WITH LIKE TYPE MATERIAL.  SPOILER, 4” MAX AND  NO WIDER THAN THE TRUNK.

2. NUMBER:  ALL CARS WILL BE NEATLY PAINTED AND NUMBERED. NUMBERING MUST BE OF CONTRASTING COLOR. DOORS 

WILL HAVE 3” WIDE AND 21” HIGH. TOP NUMBER WILL BE 3” WIDE AND 31” HIGH.

3. FRAME:  ALL UNIBODY CARS MUST HAVE ORIGINAL WHEEL- BASE WITH 108” MINIMUM WITH NO MORE THAN 1” 

DIFFERENCE FROM SIDE-TO-SIDE.  (MAY TIE REAR FRAME TO FRONT FRAME; TUBING ALLOWED) FULL FRAME CARS MUST 

REMAIN ORIGINAL WHEELBASE WITH 108” MINIMUM.

4. ROLL CAGE:

    A. A ROLL CAGE CONSISTING OF CONTINUOUS HOOPS NOT LESS THAN 1.666 INCH OUTSIDE DIAMETER AND HAVING A WALL THICKNESS OF AT LEAST .095, LOW CARBON MILD STEEL TUBING REQUIRED.    HALO MUST HAVE ONE CROSSBAR.  A FULL FOUR POINT ROLL CAGE WITH A MINIMUM OF THREE DRIVER SIDE DOOR BARS AND TWO PASSENGER SIDE DOOR BARS IS REQUIRED.   DOOR BARS MUST BE WELDED TO THE FRONT AND REAR OF THE ROLL CAGE MEMBERS. NO BRAZING OR SOLDERING ALLOWED. FULL FRONT AND REAR HOOPS ARE RECOMMENDED.  ADDITIONALLY, EACH CAGE MUST HAVE A DASH BAR AND A MINIMUM OF TWO DOWNRIGHTS NOT LOWER THAN 12” FROM THE TOP OF THE ROLL CAGE CORNERS EXTENDING DOWN AND BACK TO THE FRAME FOR ADDITION SUPPORT. ALL 90 DEGREE ANGLES MUST HAVE GUSSETS.

    B. DRIVERS HEAD MUST NOT PROTRUDE ABOVE THE CAGE WITH THE HELMET ON AND THE DRIVER STRAPPED IN THE DRIVER SEAT.

    C. NO BRACE BARS FORWARD OF THE CAGE MAY BE HIGHER THAN STOCK HOOD HEIGHT.  MAY HAVE BARS IN FRONT OF RADIATOR, WITHIN THE CONFINES OF THE BODY.

5. DRIVERS EQUIPMENT: SFI APPROVED GLOVES, FIVE POINT SAFETY BELTS, MINIMUM 3” LAP AND 3” SHOULDER. SHOULDER HARNESS MUST BE MOUNTED AT OR BELOW THE SHOULDER LEVEL.  CROTCH STRAP MANDATORY SFI APPROVED. FIRE RESISTANT FIRE SUIT REQUIRED;  HELMETS ARE REQUIRED AND MUST BE (SHCA) 85 SNELL OR BELL APPROVED OR BETTER. NECK BRACE AND RACING SEAT REQUIRED AND THAT THE RACING SEAT MUST BE SECURED TO ROLL CAGE. DRIVERS EQUIPMENT MUST ACCOMPANY CAR AT TIME OF INSPECTION AND WORN AT ALL TIMES THE CAR IS ON THE TRACK EXCEPT DURING PACKING. TECHNICAL APPROVED DOOR WINDOW NET, DIAL TYPE FIRE EXTINGUISHER, AND A FRONT WINDOW SCREEN IN FRONT OF THE DRIVER IS REQUIRED. ROLLBAR PADDING IS REQUIRED IN DRIVER’S COMPARTMENT.  SFI RACING SHOES RECOMMENDED.

6. ENGINES:   ALL ENGINES USED IN COMPETITION MUST BE ABLE TO BE USED IN PRODUCTION U.S. PASSENGER CARS WITHOUT ALTERATION. OPTIONAL SOLID MOTOR MOUNTS MAY BE USED IN STOCK LOCATION. CASTINGS AND FITTINGS MUST NOT BE CHANGED. NO MACHINE WORK ON OUTSIDE ENGINE OR ON THE FRONT OR REAR OF CAMSHAFT.   FLAT TAPPET CAM/LIFTERS AND STUD-MOUNTED ROCKER ARMS ONLY (NOTE...YEAR 2008 NO STUD GIRDLES, MAY ONLY USE STEEL STAMP ROLLER TIP ROCKER ARMS).  NO LIMIT ON ENGINE C.I., BUT MUST RUN GM WITH GM, FORD WITH FORD, ETC. O.E.M. FACTORY INTAKE ( NO AFTER MARKET INTAKES). HEADERS OPTIONAL, IMCA MUFFLERS REQUIRED.  NO 180’S. STOCK O.E.M. MECHANICAL FUEL PUMPS ONLY. NO ELECTRIC FUEL PUMPS. ALL CARS MUST HAVE OPERATIONAL STARTER. ENGINE COOLERS OPTIONAL (CANNOT BE LOCATED IN DRIVERS COMPARTMENT.)

7. CARBURETORS:    ALL CARS MUST RUN A HOLLEY TWO-BARREL MAXIMUM 500 CFM OR STOCK O.E.M. FOUR-BARREL

CARBURETOR, NO HOLLEY FOUR-BARREL CARBURETOR.  ADAPTER PLATE MAYBE USED, 1” MAXIMUM.     

8. COOLING SYSTEM:   ONE RADIATOR IN STOCK LOCATION. NO SECOND RADIATORS. REDUCTION PULLEYS, ELECTRIC FAN OPTIONAL. NO ELECTRIC WATER PUMPS.

9. TRANSMISSION:   ONLY OEM TRANSMISSION WILL BE ALLOWED. STEEL FLYWHEELS ONLY. NO COUPLERS. AUTOMATIC TRANSMISSION MUST HAVE OPERABLE TORQUE CONVERTER,  SCATTER SHIELD REQUIRED.  STANDARD TRANSMISSION MUST HAVE A SINGLE OEM TYPE CLUTCH WITHIN BELL HOUSING. CLUTCH TYPE TRANSMISSION WILL HAVE AN EXPLOSION PROOF BELL HOUSING. MAY CONSTRUCT A SHIELD OF AT LEAST 1/4” THICKNESS BY 6” WIDE STEEL. THAT COVERS THE CLUTCH AREA BY 180 DEGREES. IT MUST BE SECURELY FASTENED. ONE TRANSMISSION COOLER IS OK IN ENGINE OR TRUNK COMPARTMENT ONLY. IF IN TRUNK, THE LINES MUST BE STEEL, AND RUN IN CONDUIT.

10. SUSPENSION & STEERING COMPONENTS:  QUICK STEERING OPTIONAL, QUICK RELEASE STEERING WHEEL OPTIONAL. NO TILT STEERING. ANY O.E.M. CAR OR TRUCK REAREND AND FLOATERS ALLOWED, BUT NO AFTERMARKET OR QUICK CHANGE DEVICES. REAR SUSPENSION MUST MATCH FRAME WITH STOCK COMPONENTS ONLY, I.E. NO PANHAND BARS.  FRONT SUSPENSION & STEERING MUST BE OEM IN STOCK LOCATION.  BOTTOM A-FRAMES CANNOT BE ALTERED OR MOVED.

11. RACING FUEL CELL REQUIRED: FUEL CELL MUST BE COMPLETELY ENCLOSED IN FULL METAL CONTAINER. ALL FUEL CELLS MUST BE SECURED WITH TWO STEEL STRAPS 2” WIDE ATTACHED TO THE FRAME OR ROLL CAGE.  COMPLETE FIREWALL MUST BE BETWEEN DRIVER AND FUEL CELL. MUST BE STEEL.  FUEL LINES INSIDE CAR MUST BE STEEL OR RUN IN CONDUIT. GAS ONLY. NO ALCOHOL.  ROLLOVER VALVE REQUIRED.  SEE TRACK GENERAL RULES ON PAGE 3.

12. DRIVE SHAFT:  MUST BE PAINTED WHITE. MUST HAVE HOOP AROUND HALF OF DRIVE SHAFT 6-12” FROM FRONT YOKE.

13. SHOCKS:  ONE PER WHEEL;  NO AIR SHOCKS OR ADJUSTABLE COIL COVERS.

14. BRAKES:  OPERATIONAL ON AT LEAST 3 WHEELS. DRUM OR DISK COMBINATION. 

15. TIRES AND WHEELS:  ALL WHEELS MUST BE STEEL WITH AN 8” MAXIMUM WIDTH.  D.O.T.  TIRES ONLY WITH A MAXIMUM OF 9” TREAD SURFACE.  NO GROOVING, NO MUDGRIP, IMCA STAMPED TIRES ALLOWED.  BEADLOCKS OPTIONAL ON THE RIGHT REAR ONLY.

16. BALLAST:  WEIGHTS MUST BE SECURELY MOUNTED OUTSIDE DRIVERS COMPARTMENT WITH 1/2” BOLTS MINIMUM  TO FRAME OR ROLL CAGE, MUST BE PAINTED WHITE AND HAVE THE CAR NUMBER ON IT. 

17. BATTERY:  BATTERY MUST BE SECURELY ATTACHED TO FRAME OR ROLLCAGE WITH METAL STRAPS AND MUST BE ENCLOSED IN A BOAT TYPE BATTERY BOX WITH COVER.

18. ENGINE CLAIM / SWAP RULE: SEE GENERAL RULES.  DOES NOT APPLY DURING THE FIRST RACE NIGHT OF THE SEASON, OR TO A DRIVERS FIRST NIGHT AT THE TRACK.