2008 Modified Rules

1. DRIVER AGE REQUIREMENT
Driver registration is open to persons 16 years of age or older. Age requirements are subject to change and will be affected by insurance coverage. All drivers who are less than 18 years of age must have all required releases and waivers on file at Sedalia's State Fair Speedway.

2. SAFETY
Full face helmets with a face shield are mandatory and must be Snell SA 2000 or newer certification. Fire suits (minimum 1 layer SFI-5 rating) are required. Fire retardant neck braces, gloves and shoes are required. Nylon or vinyl shoes are not allowed. Arm restraints or full-size (minimum 16"x20") driver-side window net required (no string-type nets). Window net to be mounted so latch is at top front of window. Minimum 3” wide five point safety belt assembly required. The shoulder harness must be mounted securely to the roll cage at a point below the driver’s shoulder height. Restraint equipment may not be over 2 years old and must be in good condition. All helmets and safety apparel must have rating/tag label intact. Roll bar padding required in driver compartment. Fire retardant padding recommended. Aluminum seats only. Seat must be mounted inside the frame rail and ahead of the rear tire. Bottom of seat can be no lower than the bottom of the frame rail. Kill switch required within easy reach of driver. Switch must be clearly marked 'OFF' and 'ON'. 360-degree drive shaft loop required and must be constructed of at least quarter-inch by two-inch steel, or one-inch tubing, mounted six inches back from front U-joint. Steel drive shafts and yokes only. Drive shaft must be painted white. Head and neck restraint system recommended, but not required.

3. ROLL CAGES
Must consist of continuous hoops not less than 1.666-inch outside diameter with a wall thickness of at least .095-inch. Low carbon, mild steel tubing is recommended. Must be frame-mounted in at least six places. No brazing or soldering allowed. Must consist of a configuration of front and rear hoops connected by tubing on the sides or side hoops. Driver's head must not protrude outside cage with helmet on and strapped in driver's seat. Must have minimum of one cross bar in top halo of roll cage. Roll cage must be securely supported and braced. Protection of feet is mandatory. Bar across back of engine with vertical bars and rub rails, or similar protection. No brace bars forward of cage may be higher than stock hood height. Main cage no further forward than engine plate.

4. DOOR BARS
A minimum of three driver side door bars, at least 1.5-inch O.D., must be as parallel with the ground as possible, and located perpendicular to the driver so as to provide maximum protection for driver, but without causing undue difficulty in getting into or out of vehicle. The side bars must be welded to the front and rear of the roll cage members. Must have at least one cross door bar, minimum 1.25-inch O.D., on passenger side of car, either horizontal or angled. Steel door plates, 18 gauge or .049-inch minimum thickness metal, must be securely welded to outside of door bars on driver's side. Plate must cover the area from the top door bar to the bottom door bar and from the rear down post to five inches in front of the seat. Must be visible for inspection.

5. ELECTRONICS
No transmitting or listening devices in car. No electronic monitoring computer devices capable of storing or transmitting information except tachometers allowed. No digital gauges. No electronic traction control devices allowed. No adjustable ignition control boxes allowed. Only one ignition box allowed on car. The only changes that can be made with ignition box is rev-limiter settings, and only one high-end setting is allowed. This setting can be changed through one chip only, or an internal setting inside the box. No timing retard controls allowed.

6. EXHAUST
Exhaust system must be mounted in such a way as to direct spent gasses away from cockpit of vehicle, away from ground, and away from areas of possible fuel spillage. Mufflers required.

7. FUEL SYSTEM
Racing fuel cells required and must be mounted by at least two solid steel straps, two inches wide around cell. Fuel cells must be enclosed in steel container and must be mounted securely behind rear axle and between the rear tires, no lower than six inches off the ground, protected by roll-cage tubing . Protective tubing must cover the rear and extend past both sides of fuel cell. Fuel cell must be a minimum of four inches ahead of rear bumper and no part of fuel cell shall be lower than protective tubing. Fuel cells must have check valves, and bladders are highly recommended. Fuel cells are limited to 32-gallon maximum capacity. Pick-up must not be underneath fuel cell.

8. FUEL
May be either gasoline or alcohol. NO Nitrous Oxide. No performance-enhancing fuel additives of any kind. One 2- or one 4-barrel carburetor allowed; must be naturally aspirated. NO fuel injection; NO electric fuel pumps.

9. BATTERIES
One 12-volt battery only, must be securely mounted and shielded. All vehicles must have the capability of starting without being pushed or pulled. All cars must join lineup on demand, unaided, or go to rear of that race.

10. WEIGHTS
Loose objects and/or weights must not be used in driver's compartment or outside of the body or hood area. Any weights added to other areas of vehicles must be securely mounted and must be painted white and have the car number on it, and attached with at least two half-inch bolts. No titanium products, parts or components allowed anywhere on race car. No gun-drilled, tubular or hollow bolts or studs anywhere on car. Car and Driver must weigh a minimum of 2450 lbs AFTER RACE.

11. TIRES AND WHEELS
McCreary American Racer G-60 (KK704) or IMCA stamped Hoosier G60. No softening or conditioning of tires allowed. No re-caps allowed. All wheels must be steel. No wide-five wheel adapters allowed. Aluminum or steel spacers allowed. May use bead lock, on right side only. External, steel bead lock only and it cannot make the wheel any narrower than 8 inches and no wider than 8.75 inches. Must use only steel bolts. Foam type or mud cap allowed on right side only. May weld three tabs, no more than two inches long, on wheel for mounting of mud cap. Bleeder valves are allowed. Grooving and siping allowed.

12. FRAMES
No part of race car can be lower than four inches from the ground (exception is front cross member and oil pan). Factory production complete full 1960 or newer parallel American passenger car frames only. Frames may be cut in rear only at point not further than 36 inches from center of rear end housing. No front clips or tube type allowed. Maximum two inch wide by four inch tall frame stiffener may be welded directly to outside of frame rail. Frames may not be widened or narrowed and must be able to support roll cage on both sides. Must be full and complete both sides. Front cross member must remain full and intact where joined at the frame rails, center of cross member may be notched for radiator and/or steering clearance only. No Jeep, Bronco (etc.) or four-wheel drive frames allowed. No sports car frames allowed. No front wheel drive allowed. Minimum wheelbase, 108 inches, both sides. Measured from center of front spindle to center of rear axle. No tolerance. Maximum overall width (front or rear) shall not exceed 78 inches from outside of tire to outside of tire.

13. SUSPENSION AND STEERING
Front suspension and steering must be unaltered, approved OEM, be in stock location, and must be replaceable by stock parts. Outer tie rod end and adjustment sleeve may be replaced by a minimum .625-inch rod end and steel tube. Weight jack must be in original center line of spring. Stock passenger car spindles only; no fabricated spindles. Spindles can be ground for brake caliper clearance only. Bottom A-frames cannot be altered or moved (exception: can weld shock mount on A-frame). Steel after market parts may be used as stock components as long as they mount in the stock location and are the same size as the OEM parts and may not be adjustable. No offset lower control arm bushings. Tube-type upper A-frames allowed and can be moved. Front sway bar must be approved OEM. No aluminum or fiberglass suspension or rear end parts allowed. Steering box must be steel approved OEM and must remain within original bolt pattern for type of frame used. No rack & pinion allowed. Steel steering shafts and knuckles only. In-cockpit steering may be modified to suit driver's taste, but must be kept on left side of cockpit. No center steering allowed. Steel coil over eliminators or steel/aluminum coil over kits allowed. One mechanical traction bar (pull or lift, not both) Rear of frame may be altered to accept leaf or coil springs; any coil spring must be at least 4.5 inches outside diameter. One steel coil spring per wheel only. No torsion bars allowed in rear. Progressive springs allowed only on pull or lift bar. No devices allowed that would enable driver adjustment to alter wheelbase or for weight jacking while car is in competition. No air shocks or air bags allowed. One shock per wheel only. One Additional shock allowed on rear suspension. No covers on suspension parts except clear cover on slider and a shield to protect the shocks. This shield can cover no more than the front half of the shocks. No Schrader valves allowed.

14. BRAKES
Brakes must be operated on all four wheels and must lock up all four wheels during inspection. Handles must be removed from brake shut offs. Proportioning valve allowed, front to rear only. Brake lines must be outside frame rails and visible. Vented rotors only. Rotors cannot be lightened. Rotors may be re-drilled for different bolt pattern or larger studs. Must be steel, approved OEM calipers, and they cannot be lightened. No titanium products, parts or components allowed anywhere on race car. No gun-drilled, tubular or hollow bolts or studs anywhere on car.

15. BODIES
1970 or newer American compact passenger car only, no panel vans or station wagons. Stock appearing front windshield and rear window support unit, painted roll bars not acceptable substitute. May utilize a flat half-windshield, with no wings, mounted to the roll cage. Mirrors not allowed. Must have a minimum of three windshield bars in front of driver. Cowl panel in front of driver can be no wider than cockpit and no farther back than the steering wheel. Firewall and floorboards are mandatory. Fiberglass or metal duplicates of body parts are permitted. Handmade body parts may be constructed of steel, aluminum, or fiberglass. All cars in competition must have a complete paint job, no reflective doors or quarter panels. No plastic body parts allowed. Body must be the same width, front to rear, and parallel to the frame. Original roof line of vehicle must be maintained. Must be full size roof. May be aluminum but must be same size as full size fiberglass. Flat roofs will be allowed with a maximum one inch difference between the front of the roof and the rear of the roof. This measurement will be from the deck. No wings or any other ground effects are allowed anywhere outside or inside car. 8" spoiler allowed measured from deck. Spoiler mounts, maximum of 4, no taller than 8” high measured from deck. Sail panels must closely resemble examples shown on “Modified Body Dimensions” at end of these rules” and be the same on both sides of car. Any reinforcing lips on rear of sail panels must be 180 degree bends. All cars must be numbered with large legible numbers on both sides, on top and rear panel. Numbers on sides and top of car must be in contrasting color from body, be at least four inches thick and at least 20 inches high. Sponsors' names must not interfere with car numbers and must be neatly lettered. Engine compartment will remain open, no side panels; hood sides may have maximum four-inch drop and must be enclosed at rear of hood; maximum hood scoop height - six inches. Passenger side of body must be no further forward than rear of block. No panel in front of right door to engine compartment. No inner panels. Driver and passenger side windows must have at least 12-inch opening, measured at center of window, between the lowest point at the top of window, whether the roof or roll cage, and the highest point at the bottom of window, whether the interior or body. (See “Modified Body Dimensions” at end of these rules)

16. TRANSMISSIONS
Must have at least one gear forward and one reverse, plus a neutral position. With motor running and car in a still position, driver must be able to engage car in gear and move forward, then backward. No five speed transmissions, 'in and out' boxes, or quick change devices allowed. All manual gear-type transmissions must have a standard OEM appearing case. Disc-type clutch must be inside an explosion-proof steel bell housing. Bert or Brinn transmission allowed. No ball splines. Automatic transmissions must remain in OEM stock appearing automatic case. Original bell housing must remain. Must have an approved scatter shield or blanket. Scatter shield may be constructed of quarter-inch by three-inch steel, 270 degrees around flex plate or flywheel.

17. BUMPERS
Center of top bumper bar, front and rear, must be 18 inches, plus or minus two inches, from ground. Steel bumpers must be used both front and rear. Two-bar front bumpers must be mounted frame end-to-frame end, no wider than the width of material outside frame horns, with the bottom loop parallel to the ground. Top bar must be directly above bottom bar so bumper is perpendicular to ground. Must be made of minimum 1.25-inch tubing and must be able to support car if lifted by wrecker. Rear bumper, steel nerf bars and bodies must not extend beyond width of rear tires, and must not contain any sharp edges. Rear bumper no more than two inches wider than body on each side. Rear bumper must resemble one of three configurations. (1) Straight bumpers can be no wider than five inches outside each frame rail. (2) If the bumper is wider than that it must be bent forward on the ends at a 90-degree angle. (3) A bumper constructed in a loop design. (See examples in “Modified Body Dimensions” at end of these rules.

18. REAR END
Any approved OEM passenger car type or truck rear end may be used. No aluminum allowed, except lowering blocks, axle cap, and drive flange. A one-inch inspection hole in center section is recommended. Full steel spool, steel mini spool or welded rear ends only. Steel axles only. Quick change is optional: steel tubes only; ten inch ring gear only; pinion and carrier bearings must be tapered; titanium is not allowed; wide-five wheel patterns are not allowed; aluminum spools are permitted; magnesium will be permitted until such date that the cost increases, at which time only magnesium rear ends purchased prior to that date will be permitted and must have original serial number. No cambered rear ends, one piece drive flange only. No electronic or mechanical traction control devices allowed (includes Gold Track, TrueTrack or similar type components). No torque dividing differentials allowed.

19. ENGINES
No aluminum blocks! Aluminum heads allowed with 50 pounds of weight (25 lbs. on each side) added in front of the bell housing. Any American make engine may be used as long as rear of engine (bell housing flange) is mounted at least 72 inches forward from the center line of rear axle. Engine offset must be kept within two inches of centerline of front cross member with engine level. Engine height minimum will be 11 inches from ground to front center of crankshaft. All engines used in competition must be able to be used in conventional passenger car without alterations. Motor mounts cannot be removed or altered. Castings and fittings must not be changed. No machine work on outside engine or on front or rear of camshaft. NO magnetos. 'Wet' oiling system only. Oil coolers must not protrude above interior. Cooling system may be modified. Any overflow tubes must be directed to the ground, between frame rails. Radiators to be mounted in front of engine only.