F.1.10 Primary Structure
The combination of the following components:
• Front Bulkhead and Front Bulkhead Support
• Front Hoop, Main Hoop, Roll Hoop Braces and Supports
• Side Impact Structure
• (EV Only) Tractive System Protection and Rear Impact Protection
• Any Frame Members, guides, or supports that transfer load from the Driver Restraint System
Explanation
The Primary Structure is most of the essential components of the chassis. If the car does not have a lot of external components with tubes acting as component protection, the Primary Structure will basically be all of the chassis.