The rules and/or regulations set forth herein are designed to provide for the
orderly conduct of racing events and to establish minimum acceptable
requirements for such events. These rules shall govern the condition of all
events, and by participating in these events, all participants are deemed to
have complied with these rules. 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 reasonable and appropriate
deviation from any of the specifications herein or impose any further
restrictions that in his/her opinion do not alter the minimum acceptable
requirements. NO EXPRESSED OR IMPLIED WARRANTY OF
SAFETY SHALL RESULT FROM SUCH ALTERATION OF
SPECIFICATIONS. Any interpretation of the rules is left to
the discretion of the officials. Their decision is final.
The Management of Tennessee National Raceway Inc.
PRINT FRIENDLY VERSION OF RULES
E-MOD RULES 2013
– 1970 or newer American compact passenger car only (no panel vans or station wagons).
– An aluminum half-windshield may be used on driver's side front window opening only. Mud deflector, sun visor.
– Stock appearing front window support units must be used (painted roll bars are not acceptable substitutes).
– A minimum window opening of 12” must be maintained on all four window openings (front, back, left and
– OEM Gremlin roofs are not allowed.
– Original roof line of vehicle must be maintained with a maximum of 5" of slope from rear to front. No more
than 1.5" stiffener allowed at the rear of the roof and must turn down perpendicular to the ground.
– Sail panels must be of matching design with matching styles on both sides of racecar.
– Sail panels may have no more than 4" bow from top to bottom, no more than 2” bow front to back and
maximum 5" tall at rear of decking and must remain separate from rear spoiler and spoiler supports.
– Hood may be no more than 2" above decking. Reverse hood rake is not allowed. Hood must be level or slope
forward toward nose of racecar.
– Belly pans are not allowed. A belly pan will be defined as any object or material that alters the airflow under
– Panel(s) in front of the right door next to the engine compartment are not allowed.
– Bodies with excessive damage (as determined by an official) will not be allowed to compete.
– After market plastic nose permitted.
– Maximum 2" lip on front nose.
– Maximum 5" spoiler is permitted with a maximum of 2 center supports and 2 side supports.
– Spoiler supports may be a maximum 15" long, maximum 2" tall at front and maximum 6" tall at back,
and may not exceed 6" tall for more than one-half of the overall length of the spoiler support.
– Aluminum roofs are permitted.
– Excluding the hood and nose piece, the top body may extend no further forward than the back of the
engine block, and the bottom no further forward than 6".
– Skirts and/or engine covers are not allowed.
– Center of bumpers (front and rear) must be at least 16" from the ground and no more than 20" from
– Both front and rear bumpers must be used, and must not have any sharp edges. Bars must be
capped on ends. Front bumper
must be mounted with the bottom loop parallel to ground. Bumpers must be made of a minimum of
one and 1 1/4" tubing and must be able to support the racecar if lifted by a tow vehicle.
– Rear bumpers and side rail bars must not extend beyond the width of the rear tires.
– Rear bumpers may be constructed of tubing or flat stock. Rear bumpers may be no more than 2"
wider than the body on each side and may not be open-ended
– All racecars must be numbered with large legible numbers on both sides, on top and on the nose.
Numbers on the sides of the racecar should be in contrasting color from the body and be at least 4"
thick and at least 18" high. Top numbers should be at least 4" thick and 24" high.
–Overall width of the racecar may not exceed 78".Width shall be measured from the widest
points on each side of the tires.
2. ROLL CAGES:
– Round steel tubing, seamless roll-over bars are required for the basic roll cage, and must be acceptable to officials. Acceptable tubing is as follows: 1.75" by 0.9" or 1.5" by 0.095" for mild steel and DOM tubing. Aluminum and/or other soft metals are not allowed. Roll bar connections must be properly welded.
– Roll bars within the drivers reach must be padded with an accepted material as determined by an official. Fire retardant material is highly recommended.
– Installation and workmanship must be acceptable to officials.
– Must be frame-mounted in at least 6 places.
– Must consist of a configuration of front and rear hoops connected by tubing on the sides or side hoops.
– With helmet on and driver securely strapped into the racing seat, top of drivers head must not protrude above the roll cage.
– Must have a protective screen or bars in front window opening in front of drivers face.
– Protection of drivers feet utilizing a bar across the back of the engine with vertical bars and rub rails or similar protection is mandatory.
– Brace bars forward of roll cage may not be higher than the stock hood height.
– A minimum of 3 driver side door bars must be parallel to ground and located perpendicular to the driver so as to provide maximum protection for the driver, but without causing undue difficulty in getting in or out of the racecar. Side bars must be welded to the front and the rear of the roll cage members. Door bars with a thickness of less than 0.9" should have 4 bars at least 1.5" in diameter at a minimum of 0.083" thickness and be gusseted in place. The door bars must have 6 vertical studs per side of 1.75" by 0.083" minimum seamless round tubing equally spaced.
– 1964 or newer OEM perimeter American rear-wheel drive passenger car frame only.
– No sports car frames. Jeep, Bronco or similar four-wheel drive frames are not allowed. No front wheel drive.
– Frame must be full and complete, cannot be widened or narrowed, and must be able to support roll cage on both sides.
– Weight jack within 1" of original center line of spring tower.
– Frame may be cut a maximum 36" forward from center of rear end housing.
– Frame horns may be removed in front of steering box.
– Frame may be notched maximum one inch at for tie rod and shock clearance.
– Front crossmember may be notched and boxed for radiator and/or steering clearance.
– Maximum 7" wide opening in side of spring tower for spring removal.
– Maximum overall width shall not exceed 78" from outside of tire to outside of tire.
– No part of frame can be lower than 4" from ground except front cross member.
– Wheelbase must be a minimum of 108" on both sides and a maximum of 112" on both sides (no tolerance).
– Tubular front clips are not allowed.
– Loose objects and/or weights are not allowed.
– Air bags are not allowed.
– Rear view mirrors are not allowed.
– Floor and firewall must be complete in the drivers compartment.
– A minimum window opening of 12" must be maintained. Driver must be able to exit the racecar from both sides.
– Must be OEM and remain within original bolt pattern for type of frame used
– Rack and pinion is not allowed.
– May be modified to suit driver, but must remain on left side of cockpit (no center steering).
– Quick-release metal coupling on steering wheel is mandatory. Plastic couplings are not allowed.
– Factory-manufactured racing seats are mandatory, and must be acceptable to officials.
– Homemade aluminum, plastic or fiberglass seats are not allowed.
– Must be properly installed and seat back cannot be back further than rear edge of quarter post.
– High-back aluminum seats only. Full containment racing seats are strongly recommended.
7. FRONT SUSPENSION:
– All components must be steel, aftermarket tubular A-Frames may be used as stock replacements as long as they mount in the stock location and are the same dimensions as the OEM parts.
– Upper control arms can be moved.
– Aluminum cross shafts on tubular uppers are allowed.
– Stock passenger car spindles only, must match side to side make and dimensions. Fabricated spindles are not allowed.
– Bottom A-frames mounts must be in stock location on frame. Cannot be altered or lightened.
– Front sway bars may be used. Must be made of steel and may be attached to the bottom A-frame using steel heim joints. Must be solid full-length OEM.
8. REAR SUSPENSION:
– No floating birdcages allowed.
– No brake floaters allowed.
– All suspension points must mount directly to the rear end. (NO Floating suspension parts)
– Suspension or rear-end parts, including jack bolts and mounting brackets, must be made of steel.
–Steel or aluminum coil-over eliminators/kits allowed.
THREE LINK DESIGN:
– One lower control arm per side, 15" minimum, 22" maximum.
– Must use one upper control arm, pull bar or lift arm.
– Must use minimum 19" Panhard or J Bar.
– Spring sliders permitted.
LEAF SPRING DESIGN:
– Steel Mono or multi leaf springs allowed
– No fiberglass/carbon fiber springs permitted.
– Coil springs must mount centered on top of rear end housing.
– Adjustable aluminum lowering blocks allowed.
– Pull bar or Lift arm permitted.
– No Panhard or J Bar.
OEM FOUR LINK DESIGN (GM METRIC REAR):
– Upper control arm mounts must be minimum 22" separation on frame.
– Upper control arms must mount on top of differential housing on rear end.
– One lower control arm per side, 15" minimum, 22" maximum.
– No Panhard or J Bar.
– No Pull bar or Lift arm.
– Spring Sliders permitted.
9. REAR END:
– Any steel OEM passenger car or truck non-cambered rear end (housing and carrier) allowed.
– Safety hubs (floater rear end) allowed.
– All components must be steel, except lowering blocks.
– Full steel spool, steel mini spool or welded rear ends only. Must be locked rear end.
– Steel axles only.
– No quick change rear ends.
– No torque dividing differentials.
10. SHOCKS:($100 SHOCK BUY RULE)
– One shock per wheel only.
– One additional shock allowed in pull bar/lift arm area.
– Steel non-adjustable shocks only.
– No Canister or shrader valve shocks.
– Threaded coil over shocks not allowed.
– All coil springs must be at least 4.5" outside diameter.
– Steel springs only.
– Bump stops (internal or external) are not allowed.
– Progressive rate springs are not allowed except on the pull bar, lift arm.
– Must be securely mounted inside frame rails.
– One (1) 12-volt battery only (no 16-volt batteries).
13. FUEL SYSTEM:
– Automotive gasoline, racing gasoline.
– E-85 Racing fuel not allowed.
– No Alcohol, or oxygenated fuel.
– No Electric Fuel Pumps.
– No Belt driven fuel pumps. Pumps must bolt to block in stock location.
14. CARBURETOR:($400 BUY RULE)
– Must be Holley 500 CFM unaltered two-barrel (Part No. 4412).
– Grinding and/or polishing of any kind is not allowed.
– Throttle bore maximum is One (1) and 11/16" in diameter.
– Venturi maximum is One (1)and 3/8" in diameter.
– Adapter plate or spacer allowed. One (1) and 1/4 Inch allowed between carburetor and top of intake manifold.
– The choke plate may be removed. Choke tower must remain.
– Casting line at venturi must be present.
– Venturi and throttle bores measured with go no/go gauge.
15. FUEL CELL:
– Must be commercially manufactured and must be mounted utilizing at least 2 steel straps. Straps must be 2" wide at all measuring points.
– Must be enclosed in a steel container and mounted securely.
– Fuel cell may be no lower than 10" from the ground.
– A ball-type, flapper or spring or filler rollover valve is highly recommended for fuel cells without a positive seal filler neck/cap system.
– Maximum capacity of thirty-two (32) gallons.
– Steel Wheels only
– Must be 15" in diameter and 8" in width.
– A steel bead lock may be used on the right rear wheel only.
– Wheel covers are permitted on right side wheels only. Inner mud plugs are permitted.
– Wide five wheel adaptors are not allowed.
– Steel or aluminum spacer between hub and wheel is permitted, but overall width of racecar cannot exceed 78".
– American Racer G60 or KK704 stamped or non-stamped tires are permitted.
– Hoosier G60, stamped or non-stamped are permitted.
– Any Steel Belted D.O.T. 60 series tire. 275/60/15 Maximum. No Mud/Snow tires.
– Grooving and/or siping is permitted
– Altering tires with any chemicals which alter the manufacturers baseline-settings of the tire is not allowed.
– Rear Tires must punch 50 at anytime.
18. BRAKING SYSTEM:
– Must be operating on all four wheels and must lock up all four wheels during inspection.
– Must have caliper and rotor on all four wheels. Vented rotors are required on front wheels.
– Electronic brake actuators are not allowed.
– Must be single piston OEM design.
– Rotors must be steel and may not be lightened, scalloped or drilled. Rotors may be re-drilled for different bolt patterns or larger studs.
– Front-to-rear brake bias are permitted (no left to right).
– Brake shut-offs are not allowed.
– Brake lines must be visible.
19. DRIVE SHAFT:
– A loop is required and must be constructed of at least 0.25" by 2" steel. Loop must be mounted no more than 6" from the front of the drive shaft tube.
– Must be steel and minimum 2 inches diameter and be painted white.
– Must utilize OEM style distributor and ignition.
– Multiple spark ignitions are not allowed.
– Kill switch required within easy reach of the driver.
– Crank trigger ignitions are not allowed.
– GM must utilize OEM HEI type distributor. Ford may use aftermarket HEI or utilize stock-type components.
– MSD, Crane, or any other Circuit board type modules are not allowed.
– Digital gauges or digital Tachs are not allowed.
– With motor running and racecar in stationary position, driver must be able to engage racecar in gear and move forward, then backward, at time of inspection.
– OEM three or four speeds permitted.
– Automatics permitted.
– BERT, BRINN, FALCON transmissions ARE permitted. 50 lbs weight penalty mounted in front of midplate. 25lbs each side of engine. Refer to rule 25 Ballast.
– Ball spline transmissions are not allowed.
– One (1) forward gear and one (1) reverse gear must be in working order, plus a neutral position, and must be able to be shifted by driver.
– All flex plates must be SFI certified.
– Starter must bolt to engine block or in factory location. Bump starts are not allowed.
– All racecars must have the capability of starting without being pushed or pulled.
–Radiator must be mounted in front of engine.
– Zoomies, Crossovers, 180 degree, or Tri-Y headers are not allowed.
– Exhaust system must be mounted in such a way as to direct spent gases away from the cockpit and away from areas of possible fuel spillage.
– Any American made push rod engine may be used.
– Rear of engine (bell housing flange) must be mounted at least 72" forward from the center line of the rear axle - NO TOLERANCE.
– OEM cast iron block only, casting numbers must be visible. .
– 362 Cubic Inches maximum.
– Max cylinder bore allowed is 4.060".
– No grinding or lightning of block.
– Maximum of 175 PSI compression #
– Any Cast or hypereutectic pistons, or forged pistons allowed See # above
– No stroking or destroking, stock stroke for engine used, not to exceed 362 Cubic Inches.
– OEM or Aftermarket CAST cranks permitted. GM: 3.48 Max, Ford: 3.50 Max
– Only stock appearing cranks permitted. No lightened crankshafts. No Knife edge crankshafts.
– Crank Shaft must weigh a minimum of 48LBS
– Maximum 6" I beam rods, cap screw rods permitted.
– Balancing of engine permitted.
– Maximum .480" valve lift, measured at camshaft lift.*
– Hydraulic flat tappet camshafts only, Maximum of .004 valve lash measured at valve.
– Must pull 15 inches of vacuum @ 1000 RPM.
– Screw in studs permitted.
– Roller Rockers permitted. Maximum 1.5 to 1 ratio GM, Maximum 1.6 to 1 Ford see * above
– Stud Girdles are permitted.
– Shaft rockers not allowed.
– O.E.M. Cast iron stock production heads only casting numbers must be visible.
– No Aluminum Heads
– No Aftermarket Heads allowed.
– No Angle Plug Heads GM
– Maximum 2.02 intake Valve, 1.60 exhaust Valve. GM and Ford.
– Minimum 58CC chambers. see # under rotating assembly
– 3 angel valve grinding allowed
– No Bowties
– No Grinding Porting, polishing anywhere.
– The overall weight of the racecar shall be measured at the conclusion of an event with the driver in the cockpit.
– The overall weight of the racecar must be a minimum of 2,450 pounds. See Transmission rule 2500 pounds
– No allowance for fuel burn off.
– May not be mounted in cockpit, above decking, or outside of body.
– Must be securely mounted, painted white and clearly marked with the car number.
– Must be attached with at least one Grade 8 or higher 1/2" bolt.
– May not be attached to rear bumper.
– Drivers should have in their pit area, at all times, a fully charged dry chemical, fire extinguisher.
– Driver must wear required helmet, fire suit and five-point safety harness whenever the racecar is on the racetrack. This includes during track packing, warm ups, hot laps and races
– Complete one- or two-piece fire suits of a flame retardant nature are mandatory. A fire suit certified to SFI Spec 3.2A/5 is strongly recommended.
– The use of a five- six- or seven-point driver restraint system (safety belts, sub-belt and shoulder harness) is required. Factory-type shoulder belts or straps are not allowed.
– Any driver who finishes in the top 4 on the same lap as the leader may place a claim.
– Claims may only be placed by the driver, cash only.
– Claims must be filed with the tech official within 15 minutes of completion of the feature race.
– Claim must be written, stating what they are buying and from what car, and signed by driver.(see tech for form)
– Air cleaner, linkage, and adapter plate not included.
SHOCKS ($100 each):
– Includes heim Joints.
– Coil over eliminators/kits not included.
*Tech official may penalize any car not conforming to the rules with weight*