Open-Wheel Modified Rules



If these rules do not say you can do it then don’t do it! Be sure to check the general rule.

All interpretations by the track are final. You are responsible to know the track’s position on all rules. Ignorance is no excuse!

Car Frame:

Cars must weigh 7 lbs. Per cubic inch minus bum off tolerance at the end of

the race, minimum weight 2500 lbs. 56% max. Left Side.

1. Factory production complete full 1950 or newer parallel American passenger car

frames only.

a. May run Fabricated front clip but must add 25 lbs. In front of flywheel.

2. Frames may be cut in the rear only at a point no further than 36 ins. From center of rear end housing.

3. Frames will not be widened or narrowed and must be able to support the roll cage on both sides. Front cross members may be notched for radiator clearance only.

4. Minimum ground clearance of 4 inches from level ground except fuel cell which shall be 8 inches minimum ground clearence.

5. Front suspension and steering will not be altered and will be OEM Heim. Joint on end of steering optional for bump steering. Stock passenger spindles only. No fabricated spindles. Bottom A frames can not be altered or moved.

6. Tube type upper A frame allowed and can be moved.

7. No coil over shocks allowed either front or rear. No homemade coil covers used anywhere on vehicle.

8. No Jeep, Bronco, Sports car, 4-wheel drive, front wheel drive frames allowed.

9. Rear of frame may be altered to accept leaf or coil springs. Any coil spring must be at least 4 ½ inches outside diamenter. No fiberglass springs allowed. No torsion bars allowed in rear.

10. No hydraulic, Or electric weight jacks anywhere in car or on car. Rachet adjustment may be on car but not in reach in the driver compartment and rachet must be out of car when racing.

11. One shock per wheel only. Addiitional shocks in other locations permissible.


12. Minimum wheel base 108 inches on both sides. NO TOLERANCE. No aluminum or fiberglass suspension or rear end parts allowed. No alluminum drive shafts allowed.


1. 1970 or newer American Compact Passenger car only(no panel vans or station wagons.) May use steel, Alunimum or fiberglass full size roof, Should be stock in appearance, stock appearing front windshield and rear window support unit. Painted roll bars are not an acceptable substitute.

2. Fire wall and floor boards are mandatory. All body parts should be recognizable as factory production vehicle. Fiberglass or metal duplicates of body parts are permitted. Hand made body parts may be constructed of steel or fiberglass or aluminum, but should be recognizable as factory production. No slab bodies are permitted.

3. All cars will be numbered with large numbers at least 18 inches high. Numbers will be placed.

4. Original roof line of car must be maintained with maximum drop of 4 inches rear and front. No wings allowed. One 90 degree spoiler not to exceed 5 in. by 60 in. allowed on rear of car to be placed within rear 5 inches of the deck lid.

5. No ground effects allowed.

6. Engine compartment will remain open, no side panels.

7. Hoods may have a maximum of 4 inch drop and must be enclosed at the rear of the hood.

8. Bodies may not extend further forward than the back of the engine block.

9. Rear of bodies tobe securely and completely closed in with a panel of at least 8 inches verdical opening and 14 inches is highly recommended.

10. Mirrows allowed.


1. Any American made engine may be used as long as rear of engine(bell housing flange)

Is mounted at least 72 inches forward of center of line of rear axle. Engine offset must be within 2 inches of center of cross member. Center of crankshaft minimum of 11 inches from ground.

2. Any engine used in competiton must be able to be used in conventional passenger car without alterations. Castings and fittings must not be changed. No machine work allowed on outside of engine block.

3. No machine work is allowed on front or rear of camshaft.

4. No dry sumps allowed.

5. All engines must have operable self starters.

6. ALUMINUM HEADS 50 pounds of weight in front of fly wheel.


1. 3 speed, 4 speed,or automatic. No 5 speed transmission allowed.

2. No “in and out” boxes allowed.

3. Manual transmission must be clutch operated. Aluminum bell housing approved with multi-disc clutch. All other clutches must be inside explosion proof, steel bell housing. Minimum disc diameter or 5 ½ inches.

4. Automatic transmission must remain in OEM case and have approved scatter shield or blanket inch x 4inches wide band. 270 degrees around flywheel required.

5. With motor running and car in still position, driver must be able to engage car in gear and move forward and then backwards at of time of inspection.

6. Steel drive shaft required. Drive shaft must be painted white.


1. Any passenger car type rear end may be used. No aluminum allowed except lowering blocks, axle cap, drive plate and hubs.

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