Rules

The frame rules are complicated, this section is used to explain the rules.

Primary Tubing

• A steel shape with bending stiffness and bending strength exceeding that of circular steel tubing with an outside diameter of 25 mm (0.984 in.) and a wall thickness of 3 mm (0.118 in.). The wall thickness must be at least 1.57 mm (0.062 in.) and the carbon content must be at least 0.18%, regardless of material or section size. The bending stiffness and bending strength must be calculated about a neutral axis that gives the minimum values.(Page 46)

Design Direction:

• 1 3/16 OD .065 Wall

• Weight savings of 4% on primary tubing from the previous year

Driver Clearance

Minimum space is based on clearances between the driver and a straight edge applied to any two points on the outside edge of the roll cage structure. The roll cage structure for clearance purposes is primary and secondary tubing only.

• Helmet

  • 6 in

• Shoulders, torso, hips, thighs, knees, arms, elbows, and hands

  • 3 in

• No part of the driver or their clothing can extend out of the roll cage

Rear Engine Kill Switch (B.10.3)

• Location

  • Right side of car

  • Behind the RRH plane

  • Forward of the right FABUP

  • Perpendicular to the firewall (±15 deg)

  • Below named point BR but no further than 7.0 inches point BR

  • Recessed less than 2.0 inches from the outside edge of the RRH tube.

• Mounting

  • Mounted tab to RRH

  • No sharp edges

  • Switches must be mechanically fastened, no adhesives

  • Rivets and other robust captive methods are acceptable fasteners for fastening kill switches to the mounting tab. Technical inspectors will evaluate each of these designs individually.

  • Threaded fasteners meet the requirements of Article 12 - Fasteners.

• Design Direction

  • Small Sheetmetal tab

  • 1) Span from rear member to roll hoop if distance is small (photo example below)

    • provides small structural improvement to frame

    • allows for simpler geometry with thin sheet metal

    • The biggest problem with this design is the 15 degree requirement. The FABUP members can be mounted 2 inches from the point BR. By mounting them down from point BR on the RRH the outside plane from RRH to BR may be less than 15 degrees and make for a easy mounting solution.

  • 2) Gusset design off roll hoop is distance is large

  • 3d Printed mechanical clamp to attach switch

    • Lighter than bolts

Michigan 2020 Example switch

Cockpit Engine Kill Switch (B.10.3)

• Location

  • Left side of car

  • Mounted along SIM

  • Within reach of driver wearing all safety gear

  • No other switches may be mounted along SIM

  • Mounting hardware must meet

  • Threaded fasteners meet the requirements of Article 12 - Fasteners.

• Design direction

  • Gusseted design similar to the fuel tank mounting (see photo below)

    • Gussets allow for thinner Sheetmetal to be used while still providing enough strength

  • Use the same 3d printed bracket to hold the switch

Fuel tank mounting tab

Harness

Shoulder belts

• The shoulder belt mounting point (A) (see Figure) shall be positioned no higher than vertically level with each driver’s shoulders, and no lower than 102 mm (4.0 in.) vertically below each driver’s shoulders

• Lateral Spacing between 6 and 9 in center to center.

Arm Restraints

• Keep your hands in the car

• reach the kill switch

• Attach to the buckle

Head Restraint

• Must be mechanically fastened to the car

• must limit reward movement of the head

Tabs:

Reverse Light

Splash Shield

Fire Wall

• Must protect shoulder belts from damages aft of the firewall

• May contain pockets or cutouts for the shoulder belts

Body Panels

Skid Plate

Fire Extinguisher

Power Train Guards

Electrical Mounting

Tow Points

Vehicle Numbers

Transponders

RFID Tag