Pro-4 Rules
1. Any car or truck with a single or dual cam 4 cylinder engine may be run. It must be completely stock as manufactured, engine, drive train, and suspension and fuel system, except as noted below. No turbos. No rear or mid engine vehicles.
2. All glass, mirrors, body molding and trim must be removed. All insulation and any other combustible material must be removed. Steering and pedals must remain stock. Dash may be modified for roll cage clearance.
3. A box type 6 point roll cage of 1 1/2” x .095" wall minimum steel tubing is required. Roll cage legs must
be welded to 1/8” plates, 4” x 8” minimum size. Truck frames may use a 2"x3" tubing to construct a perimeter frame to attach roll cage and door bars.
4. Driver sides must have 3 bars, 1 1/2” x .095 minimum. Passenger side may be an “X” but must have 3 bars. The roll cage must be a box over, behind and in front of driver. The hoop behind the driver must have a diagonal brace. Roof
loop must have a center bar. Extra bracing inside the cockpit is allowed.
5. Doors must be welded or chained shut. Windshield must be replaced with heavy guage wire mesh.
6. Strut towers may be reinforced. Right front hubs may be reinforced. Wheel centers may be reinforced. Larger
wheel studs and nuts are recommended.
7. Passenger car tires only, no low profile tires.
Minimum Inflation for all tires shall be the maximum as determined by the manufacturer and stated on tire.
If tire has no stated maximum, It may not be run.
8. Fuel cell in steel can, or steel tank may be securely mounted in trunk. Must have firewall between the tank and driver.
9. Battery must be securely fastened down, if in cockpit it must be completely enclosed. Must run battery master
disconnect switch with in reach of driver. Third brake light must remain operable.
10. Racing seat mandatory. A quick release 5 point racing type seat belt is required. Seat and seat belts must mount
to frame or roll cage, and meet approval.
11. All cars must have a window net.
12. Must have a registered number 16” tall in contrasting colors on both doors and on roof facing driver’s side.
Driver’s name recommended on both sides of the roof above the doors.
13. No profanity or suggestive slogans may appear on the car.
14. Continuous developments in racing may necessitate changes that we cannot foresee at the time the rules are written. Hence, we may update, modify, add to or delete rules.