Showtime Speedway 2016 Open-Wheel Modified
If these rules do not say you can do it then don’t do it! Be sure to check the general rules. All interpretations by the track are final. You are responsible to know the track’s position on all rules. IGNORANCE IS NO EXCUSE!
Cars must weigh 7 lbs per cubic inch minus burn off tolerance at the end of the race minimum weight 2,500 lbs. 56% Max Left side. No burn off after race. Aluminum heads must move 50 lbs. of lead in front of flywheel. Battery cannot be used as ballast. NO TOLERANCE.
1. Factory production complete full 1950 or newer parallel American passenger car frames only.
2. Frames may be cut in the rear only at a point no further than 36 inches 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 inch minimum ground clearance.
5. Front suspension and steering will not be altered and will be O.E.M. Heim Joint on end of steering optional for bump steering. Stock passenger car spindles only. No fabricated spindles. Bottom A frames cannot 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. NO bump stops, Coil Binding and chassis limiters are not allowed.
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 springs must be at least 4 ½ inches outside diameter. No fiberglass springs allowed. No torsion bars in rear.
10. No hydraulic, ratchet or electric weight jacks anywhere in or on the car.
11. One shock per wheel only. Additional shocks in other locations permissible. Any shock on car may be claimed for $100.00 per shock. NO bump stops, Coil Binding and chassis limiters are not allowed.
12. Minimum wheel base 108 inches both sides. NO TOLERANCE. No fiberglass suspension or rear end parts allowed. No aluminum drive shafts allowed.
13. No chassis or suspension adjustments from driver’s seat.
14. May use after market adjustable center link. Spindles may be slotted for Ackerman.
MODIFIED TUBE CLIP: May run fabricated front clip but must add 25 lbs. of lead in front of flywheel.
A. MUST USE STOCK LOWERS, STEERING BOX AND IDLER ARM.
B. MUST MAINTAIN 3 ¼ “FROM LOWER CONTROL ARM BOLTS TO BOTTOM OF CROSSMEMBER AT ALL TIMES.
C. LOWER MOUNTS MUST BE SOLID AND NONADJUSTABLE.
D. MUST MEASURE 17” +/- ¼” FROM CENTER BOLT TO CENTER BOLT ON FRONT SIDE OF LOWER CONTROL ARM AND 27” +/- ¼” ON REAR LOWER CONTROL ARM.
E. ANY TUBE CLIP THAT DOESN’T MEET THESE SPECS WILL BE DEEMED ILLEGAL.
Body: See body and chassis diagrams below
1. 1970 or newer American compact passenger cars only (no panel vans or station wagons). May use steel, aluminum 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. All cars in competition must have a complete paint job. Unpainted bodies of any kind are not permitted.
3. All cars will be numbered with large numbers at least 18” high. Numbers will be placed:
4. Original roof line of car must be maintained with maximum drop of 4 inches rear to front. No wings allowed. One spoiler not to exceed 5” x 60” (Single Plane) allowed on rear of car to be placed within the rear 5 inches of the deck lid. Side spoilers may be 5” and may not extend more than 16” forward of the base of rear spoiler. Monte Carlo and Mustang (bubble style) roofs are still allowed and must follow the original roof rake dimensions.
4a. Max. 1” lip any where else on car. (max of two on nose piece and two on roof).
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 any further forward than the back of the engine block.
9. Rear of bodies to be securely and completely closed in with a panel of at least 8 inches high.
10. Driver and passenger side windows must have a minimum 12 inches vertical opening although 14 inches is highly recommended.
11. Mirrors and radios Allowed.
1. 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 the rear axle. Engine off set must be kept within 2 inches of center of cross member. Engine height minimum will be 11 inches from ground to front center of crankshaft.
2. Any engine used in competition must be able to be used in conventional passenger cars without alteration. Motor mounts cannot be removed or altered. Castings and fittings must not be changed. No machine work allowed on outside of engine block.
3. Crate Motors – 604 OK with no weight break.
4. No machine work is allowed on front or rear of camshaft.
5. No dry sumps allowed.
6. No aluminum block.
The following boxes are okay
MSD’S BOXES 6400-6420-6425-6ALN
CRANE BOXES 6000-6410 6000-6412 6000-6430
Showtime Speedway reserves the right to claim Ignition boxes.
1. Any two (2) or four (4) barrel carburetor.
2. Must be naturally aspirated.
3. No fuel injection. No electric fuel pumps.
4. No magnetos.
1. Only OEM production type transmissions allowed 3 speed, 4 speed or automatic. Aftermarket transmission okay, pending tech
approval. (i.e.. Richmond replacement (Straight cut gears OK).
2. Manual transmission must be clutch operated.
3. With motor running and car in still position, driver must be able to engage car in gear and move forward and then backwards at time of inspection.
4. Transmission must have at least one gear forward and one reverse, plus neutral position and must be able to be shifted by the driver during inspection.
5. Clutch must be inside the bell housing.
6. Clutch type transmissions must be equipped with an explosion proof steel bell housing.
7. After market multi-disc allowed. The disc must be a minimum diameter of 5 1/2 inches.
a. Drive shaft loop is required and must be constructed of at least 1/4 inch by 2 inch steel and should be mounted no more than 6” from the front of the drive shaft. The 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.
2. Quick change rear end allowed. Center section and side bells may be aluminum. Axles and tubes must be steel. No cambered tube rears.
1. Exhaust system must be mounted in such a way as to direct spent gases away from the cockpit of the vehicle and away from areas of possible fuel spillage.
1. Must be OEM. No rack and pinion allowed.
2. No center steering.
3. Aluminum wheels, a frames, and spindles are not allowed. (A-Arm mounting shaft is allowed to be aluminum.)
1. Maximum of 22 gallon fuel cell mandatory. Cutting the trunk for the fuel cell is permitted. Fuel cell must be in 22 gauge steel.
1. Must consist of continuous hoops not less than 1.666 inches outside diameter and must have a wall thickness of at least .095.
2. Must be frame mounted in at least six (6) places.
3. Must consist of a configuration of front and rear hoops connected by tubing on the sides or side hoops. Drivers head must not protrude above the cage with helmet on and strapped in the drivers seat.
4. Low carbon, mild steel tubing is recommended. No brazing or soldering allowed.
5. Protection of feet is mandatory. Bar across back of engine with vertical bars and rub rails, or similar protection.
6. No brace bars forward of cage may be higher than stock hood height.
7. Driver door bars must be as parallel with the ground as possible and located perpendicular to the driver as to provide maximum protection for the driver, but without causing undue difficulty in getting into or out of the vehicle. The side bars must be welded to the front and the rear of the roll cage member. No brazing or soldering allowed. Door bars with less than .095 thickness must have four (4) bars at least 1 ½ inches in diameter.
1. Bumpers must be used front and rear.
2. Front bumper must be mounted frame end to frame end with the bottom lop parallel to the ground. Must be made of a minimum of 1 1/4 inch tubing and must be able to support the car if lifted by the wrecker.
3. Rear bumper, nerf bars and bodies must not extend beyond the width of the tires, and must not contain any sharp edges.
4. Rear bumper must protect the fuel cell.
5. Center of bumper, front and rear, must have 18 inch ground clearance.
1. Brakes must lock up all four (4) wheels during inspection.
1. Maximum overall width (front or rear) shall not exceed 78 inches from outside of the tire right side to outside of the tire left side. No tire warmers or air bleeders.
2. Track approved tires only.
3. Left rear tire must be visible outside of body from the top, side and rear of car. Tire cannot be tucked under the body.
The track reserves the right to add weight at its discretion for the fairness of competition.