General Restrictions
a. The use of carbon fiber and/or Kevlar reinforcement, titanium, ceramic, high strength composites and similar materials is prohibited, unless specifically permitted. The use of the word “unrestricted” in any section does not indicate their allowance.
b. The use of materials other than those specified in section 9.1.1.D.a above for seals, bearing and bearing liners, thread locking systems, windscreens, mirrors, instruments, wiring, electronic systems, electrical systems, cooling, hydraulic and oil systems, etc., is permitted.
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D.7 Chassis/Frame
Formula Ford 1986 construction requirements as of January 1, 1986 as revised January 1, 201x. All new Formula F and FC cars are to be built to the specifications covered in D.7 and D.8. Exceptions specific to FC are stated in the FC rules.
a. The chassis and all bulkheads shall be of steel tube and panel space-frame construction only.
The soles of the driver’s feet shall not extend beyond the front edge of the wheel rims (in normal position; (i.e., pedals not depressed) and shall remain behind the front bulkhead. The lower main frame rails shall be a minimum of 25 centimeters (9.84 inches) apart (inside dimension) from the front bulkhead to the rear roll hoop.
Forward-facing braces that protect the driver’s legs and feet shall extend from the front roll hoop to the front bulkhead. (The front bulkhead is defined as the vertical and transverse section of the frame immediately ahead of the pedals and drivers feet. This does not preclude a secondary forward bulkhead ahead of this “front” bulkhead.)
Further reinforcement of the frame structure shall be in accordance with the allowances specifically stated herein. No other methods of reinforcement will be allowed. No panels or components other than the required and optional load bearing panels may be attached to the chassis for structural purposes.
The chassis shall carry a mandatory load-bearing floorpan, and may incorporate optional load-bearing bulkhead panels on the main and dash hoops and the front bulkhead immediately ahead of the driver’s feet. The optional bulkhead panels may be attached in the same manner as the floorpan fastening and use the same material requirements.
At a minimum, the floorpan shall extend from the rear main hoop bulkhead to the front bulkhead. Floorpan material is restricted to heat treated aluminum alloy, minimum thickness .060 inch, and/or steel sheet, minimum 18 gauge.
At a minimum, the floorpan shall be attached to the chassis lower rails at or adjacent to its full perimeter by any combination of welding, bonding, riveting, or bolting. The centers between any two adjacent fasteners shall be no more that 6 inches apart. The floorpan may not “wrap up” on to the chassis sides to any point above the top surface of the lower main frame rails.
The floorpan may be constructed in more than one section. For its entire length, the floorpan shall consist of substantially flat panel(s) in plane(s) approximately parallel to the ground plane (not counting chassis “rake”). In addition, “stepped” or sloped floorpans ahead of the dash hoop are permitted, however, the maximum vertical distance from the point of attachment to the base of the main hoop to the point of attachment at the front bulkhead shall be 25.4mm (1 inch).
b. The area between the upper and lower main frame tubes from the front roll hoop bulkhead to the rear roll hoop bulkhead shall be protected by at least one of the following methods to prevent the intrusion of objects into the cockpit.
1. Panel(s): minimum of either .060 inch heat treated aluminum (6061-T6 or equivalent) or 18 gauge steel, securely attached to the outside of the main frame tubes. No other material types will be allowed for these panels.
2. Reinforced body: at a minimum, consisting of a minimum of two layers of 5 ounce, bi-directional, laminated Kevlar material incorporated into the body which shall be securely fastened to the frame. (5 or more layers are highly recommended.)
The steel tubes used for the chassis braces in this area shall be at least equivalent to the roll hoop brace material (equal or greater material stress area and yield strength).
c. A firewall(s) that seals the drivers’ compartment (cockpit) from the engine compartment is required. Forward facing ducts may be installed to deliver air directly to the engine compartment. Air duct openings may be located within the cockpit provided the firewall is extended to prevent the passage of flame and debris from reaching the
driver.
d. Brackets for mounting components, such as the engine, transmission, suspension pickups, instruments, clutch and brake components, and body panels, may be metal, of any shape, and attached to the frame in any manner.
e. Instruments may be mounted in non-metallic panels (e.g., composite or plastic) securely affixed to the dash bulkhead.
f. Impact Attenuators: See GCR 9.4.5.G. Additional attenuators are highly recommended.
g. No engine oil or water tubes are allowed within the cockpit, except for shielded (stainless steel braid) mechanical oil pressure lines. Chassis tubes shall not be used as oil or water transport tubes.