PROUD SPONSORS
OF
THUNDERHILL RACEWAY
 







2013 E-Mod OPEN WHEEL RULES

RACECIEVERS ARE MANDATORY

BODY:
A) 1970 or newer American compact passenger car only (no panel vans or station wagons).
B) Original roof line of vehicle must be maintained with a maximum of 5" of slope from rear to front. No more than (0.5") stiffener allowed at the rear of the roof and must turn down perpendicular to the ground.
C) Sail panels must be of matching design with matching styles on both sides of racecar.
D) 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.
E) 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.
F) Belly pans are not allowed. A belly pan will be defined as any object or material that alters the airflow under the racecar.
G) Panel(s) in front of the right door next to the engine compartment are not allowed.
H) Bodies with excessive damage (as determined by an official) will not be allowed to compete.
I) After market plastic nose permitted. Maximum 2" lip on front nose.

FRAME:
A) 1964 or newer OEM perimeter American rear-wheel drive passenger car frame only.
B) No sports car frames. Jeep, Bronco or similar four-wheel drive frames are not allowed. No front wheel drive.
C) Frame must be full and complete, cannot be widened or narrowed, and must be able to support roll cage on both sides.
D) Weight jack within 1" of original center line of spring tower.
E) Frame may be cut a maximum 36" forward from center of rear end housing.
G) Frame horns may be removed in front of steering box.

H) Frame may be notched maximum one inch at for tie rod and shock clearance.
I) Front crossmember may be notched and boxed for radiator and/or steering clearance.
J) Maximum 7" wide opening in side of spring tower for spring removal.
K) Maximum overall width shall not exceed 78" from outside of tire to outside of tire.
L) No part of frame can be lower than 4" from ground except front cross member.
M) Wheelbase must be a minimum of 108" on both sides and a maximum of 112" on both sides (no tolerance).
N) Tubular front clips are not allowed.

SPOILERS:
A) Maximum 5" spoiler is permitted with a maximum of 2 center supports and 2 side supports.
B) 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.
C) Aluminum roofs are permitted.
D) 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"

E) Skirts and/or engine covers are not allowed.

COCKPIT:
A) Loose objects and/or weights are not allowed.
B) Rear view mirrors are not allowed.
C) Floor and firewall must be complete in the driver compartment.

STEERING:
A) Must be OEM and remain within original bolt pattern for type of frame used
B) Rack and pinion is not allowed.
C) May be modified to suit driver, but must remain on left side of cockpit (no center steering).
D) Quick-release metal coupling on steering wheel is mandatory. Plastic couplings are not allowed.

FRONT SUSPENSION:
A) 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.
B) Upper control arms can be moved.
C) Aluminum cross shafts on tubular uppers are allowed.
D) Stock passenger car spindles only, must match side to side make and dimensions. Fabricated spindles are not allowed.
E) Bottom A-frames mounts must be in stock location on frame. Cannot be altered or lightened.
F) 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.

REAR SUSPENSION:

A) No floating birdcages allowed.
B) No brake floaters allowed.

C) All suspension points must mount directly to the rear end. (NO Floating suspension parts)
D) Suspension or rear-end parts, including jack bolts and mounting brackets, must be made of steel.
E) Steel or aluminum coil-over eliminators/kits allowed.

THREE LINK DESIGN:
A) One lower control arm per side, 15" minimum, 22" maximum.
B) Must use one upper control arm, pull bar or lift arm.

C) Must use minimum 19" Panhard or J Bar.
D) Spring sliders permitted.

LEAF SPRING DESIGN:
A) Steel Mono or multi leaf springs allowed
B) No fiberglass/carbon fiber springs permitted.
D) Coil springs must mount centered on top of rear end housing.
C) Adjustable aluminum lowering blocks allowed.
D) Pull bar or Lift arm permitted.
E) No Panhard or J Bar.

OEM FOUR LINK DESIGN (GM METRIC REAR):
A) Upper control arm mounts must be minimum 22" separation on frame.
B) Upper control arms must mount on top of differential housing on rear end.
C) One lower control arm per side, 15" minimum, 22" maximum.
D) No Panhard or J Bar.
E) No Pull bar or Lift arm.
F) Spring Sliders permitted.

REAR END:
A) Any steel OEM passenger car or truck non-cambered rear end (housing and carrier) allowed.
B) Safety hubs allowed.
C) All components must be steel, except lowering blocks.
D) Full steel spool, steel mini spool or welded rear ends only. Must be locked rear end.
E) Steel axles only.
F) No quick change rear ends.
G) No torque dividing differentials.

SHOCKS:($100 PER SHOCK BUY RULE)
A) One shock per wheel only. STEEL BODIED OIL SHOCKS ONLY
B) One additional shock allowed in pull bar/lift arm area.
C) Steel non-adjustable shocks only.
D) No Canister or shrader valve shocks.
E) Threaded coil over shocks not allowed.

SPRINGS:
A) All coil springs must be at least 4.5" outside diameter.
B) Steel springs only.
C) Bump stops (internal or external) are not allowed.
D) Progressive rate springs are not allowed except on the pull bar, lift arm.

 BATTERY:
A) Must be securely mounted inside frame rails.
B) One (1) 12-volt battery only (no 16-volt batteries).

 FUEL SYSTEM:
A) Automotive gasoline or racing gasoline only. NO E-85 FUEL Allowed
B) No Alcohol, or oxygenated fuel.
C) No Electric Fuel Pumps.
D) No Belt driven fuel pumps. Pumps must bolt to block in stock location.

CARBURETOR:

($400 BUY RULE)

A) Must be Holley stock 4412 500 cfm unaltered 2 Barrel

B) Grinding and/or polishing of any kind is not allowed.
C) Throttle bore maximum is One 1 and 11/16" in diameter.
D) Venturi maximum is One 1 and 3/8" in diameter.
E) Adapter plate or spacer allowed. 1 and ¼” allowed between carburetor and top of intake manifold.
F) The choke plate may be removed. Choke tower must remain.
G) Casting line at venturi must be present.
H) Venturi and throttle bores measured with Go No/Go Gauge.

FUEL CELL:
A) Must be commercially manufactured and must be mounted utilizing at least 2 steel straps. Straps must be 2" wide at all measuring points.
B) Must be enclosed in a steel container and mounted securely.
C) Fuel cell may be no lower than 10" from the ground.
D) A ball-type, flapper or spring or filler rollover valve is highly recommended for fuel cells without a positive seal filler neck/cap system.
E) Maximum capacity of thirty-two 32 gallons.

WHEELS:
A) Steel Wheels only
B) Must be 15" in diameter and 8" in width.
C) A steel bead locks may be used on the right side of car only.
D) Wheel covers are permitted on right side wheels only. Inner mud plugs are permitted.
E) Wide five wheel adaptors are not allowed.
F) Steel or aluminum spacer between hub and wheel is permitted, but overall width of racecar cannot exceed 78".

TIRES:
A) American Racer G60 or KK704 stamped or non-stamped tires are permitted. Hoosier G60, stamped or non-stamped are permitted.
B) Any Steel Belted D.O.T. 60 series tire. 275/60/15 Maximum. No Mud/Snow tires or Recaps.
C) Grooving and/or siping is permitted
D) Altering tires with any chemicals which alter the manufacturers baseline-settings of the tire is not allowed.
E) Rear Tires must punch 60 at anytime.

BRAKING SYSTEM:
A) Must be operating on all four wheels and must lock up all four wheels during inspection.
B) Must have caliper and rotor on all four wheels. Vented rotors are required on front wheels.
C) Must be single piston OEM design or approved by track tech personnel.
D) Rotors must be steel and may not be lightened, scalloped or drilled. Rotors may be re-drilled E) for different bolt patterns or larger studs.
F) Front-to-rear brake bias are permitted.
G) Brake shut-offs are Allowed, Left or right across the front permitted

DRIVE SHAFT:
A) 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.
B) Must be steel and minimum 2 inches diameter and be painted white with car # painted on it.

IGNITION:
A) Must utilize OEM style distributor and ignition.
B) Multiple spark ignitions are not allowed.
C) Kill switch required within easy reach of the driver.
D) Crank trigger ignitions are not allowed.
E) GM must utilize OEM HEI type distributor. Ford may use aftermarket HEI or utilize stock-type components.
F) MSD, Crane, or any other Circuit board type modules are not allowed.
G) Digital gauges or digital Tachs are not allowed.

TRANSMISSION:
A) 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.
B) OEM three or four speeds permitted.
C) Automatics permitted.
D) BERT, BRINN, FALCON transmissions ARE permitted. 50 lbs weight penalty. 25lbs each side of engine Mid-Plate mounted in front or back of midplate.. Refer to rule 25 Ballast.
E) Ball spline transmissions are not allowed.
F) One forward gear and one reverse gear must be in working order, plus a neutral position, and must be able to be shifted by driver.

STARTER:
A) Starter must bolt to engine block or in factory location. Bump starts are not allowed.
B) All racecars must have the capability of starting without being pushed or pulled.

ENGINES:

A) Radiator must be mounted in front of engine.
B) Zoomies, Crossovers, 180 degree, or Tri-Y headers are not allowed.
C) Rear of engine (bell housing flange) must be mounted at least 72" forward from the center line of the rear axle - NO TOLERANCE.

BLOCK:
A) OEM cast iron block only, casting numbers must be visible. .
B) 362 Cubic Inches maximum.
C) Max cylinder bore allowed is 4.060".
D) No grinding or lightning of block.

ROTATING ASSEMBLY:
A) Maximum of 175 PSI compression
B) Any Cast or hypereutectic pistons

C) No Forged Pistons
D) No stroking or destroking. Stock Stroke For Engine Used, not to exceed 360 Cubic Inches.
CAST Cranks ONLY, NO STEEL CRANKS. GM: 3.48 Max, Ford: 3.50 Max, Dodge: 3.60
E) Only stock appearing cranks permitted. No lightened crankshafts. No Knife edge crankshafts.
F) I beam stock rods only, ie: Stock length Rod to make and manufacturer of the engine type: ie: Ford 6" , Chevy 5.7", Dodge
G) Balancing of engine permitted.

VALVE TRAIN:

A) Max cam 480 lift measured at cam shaft lobe lift (Times rocker arm ratio)
B) Hydraulic flat tappet camshafts only, Maximum of .004 valve lash measured at valve. Must pull 15 inches of vacuum @ 1000 RPM.
C) Screw in studs permitted.
D) Roller Rockers permitted. Maximum 1.5 to 1 ratio GM, Maximum 1.6 to 1 Ford
E) Stud Girdles are Permitted.
F) Shaft rockers not allowed.

HEADS:
A) Open Chambered Heads Only

B) No Aluminum Heads
C) No Aftermarket Heads allowed.
D) No Double Hump Heads
E) No Grinding Porting, polishing anywhere.
F) Can Hone up to 2.02 Intake Valves & 1.60 Exhaust Valves

CRATE

Performance parts 602 crate engine (part #88958602 or #19258602) All engines are sealed from the factory and such seals may not be removed, touched, modified or broken. All engines and components must be in their original form as delivered from the factory. Any changes to the factory sealed delivered configuration and assembly will result in disqualification and no points awarded. No upgrades are allowed to any engine. Any part of a sealing bolt that has been tampered with and or removed will result in a $1000 fine, loss of points for the year, loss of winnings for the night. This is considered to be a serious offense and will be treated as such. No changes are allowed to the engine – intake manifold, heads, valve covers, front cover, oil pan, harmonic balancer or any other part / or parts on / or in engine.

WEIGHT:
A) The overall weight of the racecar shall be measured at the conclusion of an event with the driver in the cockpit.
B) The overall weight of the racecar must be a minimum of 2,450 pounds. Cars running Bert, Brinn, Falcon Transmission. 25lbs added to each side of mid-plate front or back to weigh 2500 pounds
C) No allowance for fuel burn off.

BALLAST:
A) May not be mounted in cockpit, above decking, or outside of body.
B) Must be securely mounted, painted white and clearly marked with the car number.
C) Must be attached with at least one Grade 8 or higher 1/2" bolt.
D) May not be attached to rear bumper.

CLAIMS:
A) Top 4 cars can protest: Example: 4th place to 1st place protest, if 1st place illegal, you go to the next position 2nd, 3rd until Legal car found. If 1st is found protest is over.
B) Claims may only be placed by the driver, cash only.
C) Claim must be given to tech man or his designate, stating what they are prostesting/buying and from what car within 15 Minutes of the conclusion of the feature race.

CARBURETORS ($400 BUY RULE):
A) Air cleaner, linkage, and adapter plate not included.

SHOCKS ($100 Buy Rule Per Shock)

A) Includes heim Joints.
B) Coil over eliminators/kits not included.
*Tech official may penalize any car not conforming to the rules with weight*