Preble County Demolition Derby Rules and Regulations Revised 2010

General Car Regulations

1.      Any front engine, 2WD, hard top or station wagons is allowed, except 66 or older Imperials.

2.      All chrome and ornaments must be removed from outside of car.  Carpet and headliner must be removed.  All glass, including headlights, taillights, mirrors, etc., must be removed.

3.      All dirt and loose pieces must be swept clean of car.  No work to be done at track.

4.      Maximum 5 gallons of fuel.  No original fuel tanks.  Must use D.O.T. or Coastguard approved container.

5.      Driver’s door reinforcements not to extend more than 6” past the driver’s door.  No driver door hitting.

6.      A maximum of 2 batteries and one transmission cooler may be moved to any reasonable position in the car as long as they are securely fastened to the car by #9 wire, metal straps, etc., and have a suitable shield.

7.      Headers must extend straight up.  If headers are not used, you must have a 12” hole above the carburetor.

8.      Metal to patch rust must be heavier that original.  No patching holes caused by removing lights.

9.      Engine mounts may be chained, wired, or welded.  Radiator must remain in original position.

10.  Intoxicating substances or the use of such are prohibited prior to or during the event.

11.  Safety belts, approved helmet, and eye protection are required and must be worn.

12.  Drivers have one minute to make aggressive contact.  Drivers sandbagging will be disqualified.

13.  Derby officials may inspect any car at any time.  Officials reserve the right to impose additional rules.

14.  Do not leave car unless officials tell you to do so or until the last car has stopped.

15.  Fuel tank must be securely fastened, leak free, and covered behind driver.

16.  Car must set reasonably level.  Minimum height of 17 inches, maximum height of 22 inches to the bottom of the bumper.  Backend of car may not be flattened.  Bumpers must remain in stock position on frame.

17.  Inside of driver’s door must be covered by original upholstery, foam rubber or similar safe covering.

18.  Drivers only in derby cars—no riders.  Only one person in the inspection line with each car.

19.  Same car and driver winning the heat must run in the feature.  (No switching)

20.  Paint car numbers on both doors and the roof.  Use contracting colors so they are visible from the announcers stand.

21.  No patching rust on the frames in any cases.  You can dip a frame, but no overlap of frame.  Must be welded together by a simple butt weld.  No wider than a ¾ inch wide weld.

22.  All patching must be able to be pierced.

Modified Cars

1.      Doors must be fastened shut by wire, chain or welded.  Tailgates and trunk lids may be welded.

2.      Straps on doors not to exceed 1/8 inch thickness and 3 inches in width.

3.      Tubes, water, and tires inside of tires and welded or locked rear ends are permitted.

4.      All cars can be sprung with leaf springs, back shackles not to exceed ¼ inch in thickness and 4 inches in width, no longer than 9 inches.  Front shackle may only be 4 inches long (welded or bolted to the frame).  Leaf springs may be added to the rear of a coil spring car.  Maximum of 12 leaf springs per side, 4 clamps per side, and only one mainspring per side.  Springs not to exceed 3/8 inch in thickness, 2 ½ inches in width, 60 inches in length.  Clamps not to exceed ¼ inch in thickness and 2 inches in width.  Leaf springs may not extend more than 30 inches from center of rear axle to center of front eye hole.  No spring is to be longer than the mainspring.  If you choose not to leaf spring a coil spring car, you may have a plate welded on the outside of the rear humps; plate may not be bigger than 6 inches by 22 inches and no thicker than ¼ inch.  Plate must be straight across the rear humps.  Plate or Leaf spring NOT BOTH!

5.      You may use all thread to pull down your car from the shock mount to where the coil spring was to the rear end.

6.      Hoods may be wired and/or bolted, maximum of 4 bolts not to exceed 1 inch in diameter by 6 inches in length, maximum of 4 double strand wires from front of hood to bumper.  Hood hinges must not be removed and must be operable.  Springs should be removed from hinges.

7.      Six double strand twisted wires may be used between roof and cowl, providing at least a 30” hole in the center to escape fire.  No other windows may be wired.

8.      Station wagon rear floor doors must be completely removed.

9.      The only welds permitted on the frame are welding the bumpers to the frame using only stock brackets, welding the front suspension to the frame to raise the front of the car, motor mounts, and welds for the addition of brackets to add rear leaf springs to car.  Maximum bracket size is 4´and bracket may not extend across top of frame.  NO SEAM WELDING ON THE FRAME!  No added reinforcements, plating, or leading inside or outside the frame.  Factory frame hole must be open for inspection.

10.  Bumpers may have two straps on each bumper.  Strap size no bigger than 3 inches by 12 inches long by 1/8 inch.

11.  Body may be bolted directly to top side of frame.  No extra bolts in body or frame.  Body bolt washers (3” maximum).  No bolts through the bottom of the frame.  Top side of frame only.  You cannot bolt through the top of the core support with your front two body mounts.

12.  Any or all body seams may be welded.  No steel, other that ¼ inch bead of weld, on the seams.

13.  A Four-sided steel structure may be used for driver protection running no further than 12 inches behind seat, across front passenger door, dash area and driver’s door.  Must be securely fastened inside car.  THIS IS THE ONLY BARS IN THE CAR, NO KICKERS!

14.  The two-hand hole covers on 1971-1976 GM leaf spring wagons (located on the underneath side of the tailgate compartment and fastened with four screws each) must be removed.

15.  When patching rust on the body in this class it can be welded 100%.  With 2 inches of overlap.

16.  There will be no teaming!  The officials have the authority to break your stick after the first warning.  This is that warning!

Compact Cars

1.      Wheel base must be 102” or less.

2.      Doors must be fastened shut by wire, chain or welded.  Tailgates and trunk lids may be welded.

3.      Straps on doors not to exceed 1/8 inch thickness and 3 inches in width.

4.      Tubes, water and tires inside of tires and welded or locked rear ends are permitted.

5.      All cars can be sprung with leaf springs, back shackles not to exceed ¼ inch in thickness and 4 inches in width, no longer than 6 inches.  Front shackle may only be 4 inches long (welded or bolted to the frame).  Leaf springs may be added to the rear of a coil spring car.  Maximum of 10 leaf springs per side, 4 clamps per side, and only one mainspring per side.  Springs not to exceed 3/8 inch in thickness, 2 ½ inches in width, 60 inches in length.  Clamps not to exceed ¼ inch in thickness and 2 inches in width.  Leaf springs may not exceed more than 30 inches from center of rear axle to center of front eye hole.  No spring is to be longer than the mainspring.

6.      You may use all the thread to pull down your car from the shock mount or where the coil spring was to the rear end.

7.      Hoods may be wired and/or bolted, maximum of 4 bolts not to exceed 1 inch in diameter by 6 inches in length, maximum of 4 double strand wires from front to bumper.  Hood hinges must not be removed and must be operable.  Springs should be removed from hinges.

8.      Six double strand twisted wires may be used between rood and cowl, providing at least a 30” hole in the center to escape fire.  No other windows may be wired.

9.      Station wagon rear floor doors must be completely removed.

10.  The only welds permitted on the frame are welding the bumpers to the frame using only stock brackets, welding the front suspension to the frame to raise the front of the car, motor mounts, and welds for the addition of brackets to add rear leaf springs to car.  Maximum bracket size is 4” and bracket may not extend across top of frame.  NO SEAM WELDIING ON THE FRAME!  No added reinforcements, plating, or leading inside or outside of the frame.  Factory frame hole must be open for inspection.

11.  Bumpers may have two straps on each bumper.  Strap sixe no bigger than 3 inches by 12 inches long by 1/8 inch.

12.  Body may be bolted directly to top side of frame.  No extra bolts in body or frame, body bolt washers (3” maximum).  No bolts through the bottom of the frame.  Top side of frame only.  You cannot bolt through the top of the core support with your front two body mounts.

13.  Only inside body seams may be welded.  You cannot weld underneath the car (uni-body to body welding is not permitted).  The only welding on the outside of the car is the doors, hatch, or trunk lid.  No steel, other than ¼ inch bead of weld, on the seams.

14.  A four-sided steel structure may be used for driver protection running no further than 12 inches behind seat, across front passenger door, dash area and driver’s door.  Must be securely fastened inside car.  THIS IS THE ONLY BARS IN THE CAR.  NO KICKERS!

15.  When patching rust on the body in this class it can be welded 100%.  With 2 inches of overlap.

16.  There will no teaming!  The officials have the authority to break your stick after the first warning.  This is that warning!