TEXAS THUNDER MOD

2008

Chassis/Body

FRAME: 1978-1987 GM metric full frame only.

Wheelbase = 107-inches minimum, 109-inches maximum, both sides. Frame cannot be widened, narrowed, shortened, or lengthened. Front frame horns may be removed in front of steering box. Front frame may be cut for radiator clearance. Rear of frame may be removed behind the upper shock mounts and replaced with rectangle, square, or round tubing. No other frame alterations allowed.

ROLL CAGE: Must consist of minimum 1.5 inch O.D. tubing, with a minimum wall thickness of.095 inch for main cage. Cages must be steel or chromyl. X-bracing is allowed. Driver’s head must not protrude outside cage with helmet on. Roll cage must be securely supported and braced with minimum one cross bar in top halo. All bars forward of cage must be lower than hood.

DOOR BARS: Minimum three driver side door bars. Must be parallel to ground and perpendicular to driver, and welded to front and rear of roll cage. Minimum two passenger side door bars required, must have at least one cross door bar. Must have steel door plate, 18 gauge or heavier, that is securely welded to outside of driver side door bars.

BODY: Engine compartment must remain open (no side panels).  Roof posts and roofs not allowed. Aluminum or fiberglass hoods allowed and must completely cover top of radiator and engine, extending from nose to interior deck and enclosed at rear. No plastic body panels or filler panels allowed. Must have complete interior deck from side to side. Quarter panels must remain 90-degrees to ground, with a maximum 45-degree bend 4-inches from bottom.

DRIVER COMPARTMENT: Must have minimum three 5/16 inch O.D. windshield bars in front of driver. Aluminum racing seat only, must be securely bolted to roll cage. Must have complete interior deck from side to side. Floor pan must be steel or aluminum and cover entire driver compartment. Bottom of seat can be no lower than bottom of frame rail. Driver compartment must be sealed off from track, driveline, engine, fuel cell, canisters and pumps. No oil coolers allowed in driver compartment. No driver adjustable items allowed other than brake bias. No mirrors allowed.

FRONT SUSPENSION: All components must be steel, unaltered OEM, in OEM location, and match frame. No jack bolts allowed. Adjustable spring buckets are allowed. Must use OEM upper and lower A-frames and mounts.  Upper A-frame mounts may be modified and moved for caster and camber adjustment, but must remain OEM material. Lower A-frame mounts and bolt holes on frame must be in OEM location, mount may be notched for clearance. All A-frame bushings may be aftermarket, but no bearing/helm type. OEM style ball joints only, may be tacked in. Sway bars and brackets must remain OEM.

STEERING: All components must be steel, unaltered OEM, in OEM location and match frame. No lightening or welding on of any steering parts. Bolt-on spindle savers are allowed. Steel steering shafts and knuckles only. Quick Steer allowed. Quick release steering wheel required. Power steering pump and reservoir must remain one unit and be located on front of engine. No rack and pinion steering.

WEIGHT: Minimum weight of 2,350 pounds after race with driver in car. Weights must not be used in driver compartment or outside body. All weights must be securely mounted with at least two, 1/2" bolts. Any added weight must be painted white and have car number printed on weight. Solid steel fasteners only.

SHOCKS: One steel shock per wheel only. Shock must be in OEM mounts and location, using OEM style shock. Weld or screw-on shock ends are not allowed. No air, coil-over shocks, or remote reservoir shocks. Any or all shocks may be claimed by the track or another competing driver for fifty dollars each.

SPRINGS: One steel OEM-style spring per wheel in original location. Minimum 4.5-inches O.D. No progressive coil springs allowed. No torsion bars or air bags.

BUMPERS/RUB RAILS: Steel only. Two bar front bumper and single bar rear bumper must be used on car at all times and welded, or bolted securely. Must be maximum 1.50-inch O.D. tubing, .095-inch wall thickness on front and 1.75-inch tubing, .095-inch wall thickness on rear. Maximum 1.50-inch O.D. tubing, .095-inch wall thickness fuel cell protection bar required, must cover rear and extend past both sides of cell, may be welded to rear bumper. Rear bumper to not extend more than 6-inches beyond rear deck. All bumpers and rub rails must be capped with no sharp edges. Single bar rub rail from front to rear wheel allowed on each side, no center supports allowed, maximum 1.50-inch O.D. tubing and .095-inch wall thickness, must be mounted to cage at front and rear of rub rail.

TIRES/WHEELS: 275/60 or 255/60 D.O.T tires only. Tire must be able to be warranted. Grooving allowed. No re-caps. Asphalt pull offs are allowed with the correct rear end gear. 15”X 8” steel wheels in any offset allowed. External steel bead lock allowed on right rear only. One foam or plastic mud cap allowed on right rear only.  Must use minimum 1-inch O.D. lug nuts. No wheel spacers allowed with OEM studs. No bleeder valves.

BRAKES: Must be steel OEM with minimum of three working brakes. Brakes may be drum or disc. OEM dimensions for hubs/rotors and calipers must be maintained. No lightening of any brake parts. Bolt pattern may be changed. Single or dual aftermarket master cylinders allowed. Driver adjustable brake bias allowed. Additional proportioning valve allowed, but must be out of driver reach. Rear rotors may be aftermarket with maximum 12-inch O.D. No scalloped or single-phase rotors allowed. Rear caliper brackets must be welded to housing.

Engine

ENGINE SPECIFICATIONS: Must use OEM cast iron, Chevrolet made V-8 small block engines only. No bowtie, SVO or W-2 components allowed. All engines must be able to be used in conventional passenger car without alterations. No aluminum, titanium or carbon fiber components allowed. Maximum cubic inch limits: GM 362 c.i., no tolerance. No 400 or larger cubic inch parts allowed. Flat top or dished cast/hyper pistons only, Chevy must use 4 valve relief. No gas ported or floating pistons. 3.48-inch maximum GM stroke. Maximum 160 lbs. per cylinder compression, no tolerance. Compression checked with one spark plug removed, turned five engine revolutions. Oil filter system must remain OEM. Wet sump oiling system only. OEM-style rods. Chevy must use maximum 5.7-inch rod. Steel or cast OEM crankshafts only. Racing oil pans allowed. Fluid dampener balancer allowed. No roller bearings allowed. Belt driven, OEM style water pumps only. No aluminum water pumps on Chevy engine.

OIL PAN PLUG : all motors must have a one inch inspection plug (between the second and third, from the front, oil pan bolt either side will work. Which ever is most easy to access.      NO PLUG NO RACE

CYLINDER HEADS: Must use one of the following OEM GM cylinder heads (last 3 digits): 126, 185, 336, 441, 445, 487, 493, 598, 624, 862, 882, 920, 993, 997, with valve no larger than 1.94-inch intake and 1.50-inch exhaust. No Vortec, bowtie, SVO, W-2 or aftermarket heads allowed. No porting, polishing, or alterations to heads of any kind. Flat milling allowed. Guide plates, screw-in studs (3/8” only) and polylocks allowed. No stud girdles. Stamped steel, OEM style, stud mounted rocker arms only.

INTAKE: Must use unaltered OEM cast iron two or four-barrel intake. No aftermarket intake manifolds. No porting or polishing allowed. No alterations of any kind. All intakes must have unobstructed 0.250-inch vacuum fitting. One inch adapter is allowed not a spacer gaskets can not measure over ¼”

CAMSHAFT: Non-roller hydraulic cam/lifters only. Maximum lift of .420”, measured at valve. Lifter bores cannot be altered. Must be chain driven, no gear/belt drives. 12” of vacuum @ 1000 rpms

EXHAUST: Schoenfeld headers, part number 161, are the only headers allowed on Chevy engines.

FUEL SYSTEM: Racing fuel cell required with maximum 22 gallon capacity. Must be in minimum 18 gauge steel container. Must be securely mounted between frame rails in trunk area only. Any fuel cell vent must have check valves. No part of cell can be lower than protective tubing. OEM mounted, mechanical push rod fuel pumps only. No regulators, bypass fuel systems, pressurized, or return lines allowed.

CARBURETOR: One Rochester two-barrel required. Carb must remain unaltered with the exception that a circle track float may be installed. No other carburetors allowed. Carb must mount directly to intake manifold. No adapters/spacers allowed. Maximum base gasket thickness of 5/16". Any air cleaner allowed.

FUEL: 93 octane "pump gas" only. Racing fuel not allowed. No performance enhancing additives. Fuel sample may be taken from any car at any time.

ENGINE COMPARTMENT: Rear of engine (bell housing flange) must be mounted at least 70-inches forward from centerline of rear axle. Minimum 11-inch engine height from ground to center of crankshaft. One radiator allowed, steel or aluminum, 27-inches by 19-inches maximum in size, must be mounted in front of engine. Racing radiator cap and electric cooling  fans allowed. No sprinklers. Catch can required. Side engine mounts (OEM or 45-degree style) must be steel, aluminum mid-plate allowed.

BATTERY/STARTER: One 12-volt battery only. Must be securely mounted. Aftermarket starter allowed, but must bolt in OEM location. Must have capability of starting without being pushed or pulled.

IGNITION: OEM style ignitions only. GM-style HEI distributor is required, no matter make of engine (must remain one unit). Any aftermarket module may be used that fits inside the distributor with no alteration. Vacuum advance may be removed and pick-up coil locked. No external coils allowed. No GM or aftermarket ignition boxes allowed. No electronic traction control devices.

Transmission/Rear

TRANSMISSION: Only OEM production TH-350  ONLY allowed. No aftermarket transmissions allowed. Transmission fluid coolers allowed. Flex plate and converter must be steel. Must use functioning converter with a minimum 11” diameter. No direct drives, couplers, or bleeder style valve bodies. All gears must function. An approved scatter shield constructed of minimum .125-inch by three-inch steel, 270 degrees around top of flex plate is recommended .

REAR END: Must use OEM 7.5-inch GM 10 bolt rear end. Must remain stock width. No Ford or floater rear end allowed. Steel components only. Bracing of housing is allowed. OEM mounts on lower control arms must remain in OEM location. Aftermarket axles, mini-spools and C-clip eliminators allowed. Rear-ends must be locked at all times, either by welded spider gears or mini-spools. No full or aluminum spools allowed. Pinion angle cannot be changed. No quick-change devices.

Required ring/pinion ratios:

If running street tires  – 2.41 is the only ring/pinion ratio allowed

If running asphalt pull offs -2.29 is the only ring/pinion ratio allowed

DRIVE SHAFT: Minimum 2-inch diameter, white, steel drive shaft only. Steel slip-yokes only. 360-degree drive shaft loop required, constructed of at least 0.125-inch by 2-inch steel, or 1-inch tubing, mounted 6-inches back from front U-joint.

REAR SUSPENSION: All control arms and mounts must be steel, unaltered OEM, in OEM location, and match frame. No jack bolts allowed. Adjustable spring buckets allowed. Control arms may be reinforced, but cannot be shortened or lengthened. Control arm bushings may be aftermarket, but no bearing/heim type. No aluminum parts allowed, other than bushings.

Misc.

SAFETY EQUIPMENT: Roll bar padding required in driver compartment. SFI-approved full fire suit required. Fire retardant neck brace, gloves and shoes required. Driver-side window net required, minimum 16"x20" ribbon or mesh style, and must be mounted so quick release latch is at top front of window. Minimum three-inch wide five point safety belt assembly required. Must be mounted securely to roll cage. Kill switch required within easy reach of emergency personnel.

ENGINE PROTEST PROCEDURES: Within 5 minutes after race, any driver starting feature may, for $250, protest any engine. $50 of the protest fee goes to track and will not be refunded, regardless of protest outcome. Driver may not protest another driver finishing in a position behind them and may not protest same driver more than once per calendar year. Under this protest, following MUST be inspected: intake manifold, cylinder head (removal required), stroke, and visual inspection of crankshaft (pan may be removed). $200 will be returned to protestor if engine is found illegal. If engine being protested is found legal, $200 protest fee will be paid to driver being protested. If parts are found illegal, or if driver refuses to submit to protest, first infraction will result in forfeiture of all cash and contingencies, trophies and points earned in feature.

ENGINE CLAIMING RULES:   
        (A) $750 cash and exchange claim on engine, with $50 going to wrecker for pulling engines.
        (B) Claim covers carb to oil pan; water pump to rear mounting flange of block. The following items will not be included in the claim:

·         Flywheel, nor anything aft of the flywheel.

·         Breathers

·         Starter

·         Motor mounts

·         Any sending units (temp, pressure, etc.)

·         Pulleys/Fan

·         Balancer

·         Distributor

·         Plug wires

·         Headers

·         Water neck

Track has right to claim