Firewall

The firewall is a component that protects the driver from powertrain failures. The firewall is required by rule T.1.8 and T.1.9 in the FSAE rules and T 4.8 in the FS rules.

Internal Combustion

FSAE - The firewall must protect the driver against the fuel supply, oil, cooling lines, and any lithium batteries.

Construction

Most teams construct the firewall out of a layer of composite (usually carbon fiber) on top of a layer of "insulating" material. The specific sandwich panel material is less impactful for heat management to the driver compartment than the mandatory 1" of air gap between the exhaust and the firewall. There is almost no better insulator than air, and moving air is even better. Since the firewall cannot be touching the exhaust, most heat blocked by the firewall is in the form of IR radiation and is easily solved by applying a layer of reflective material. Commercial automotive solutions are available and often sponsor FSAE teams. In a pinch, aluminum tape can be used for this purpose.

Position

Since the firewall has to be between the driver and the engine, many teams use it to support the seat as a structural element of the cockpit. If the seat used for actual drivers is removable without removing the firewall, the firewall can be used as the "seat" for the Percy template during tech inspection, and the seat will be considered "padding".

EVs

Construction

The EV firewall is subject to much more stringent rules. The firewall layer facing the tractive system must be a grounded layer of aluminum between 0.5mm and 0.7mm thick. In addition, the layer facing the driver must be electrically insulating. The driver facing layer MUST not be made of carbon fiber, as it has unpredicatble and non-zero conductive properties. Frequently, fiberglass is chosen as a substitute. Because the backing layer has to be a solid sheet of aluminum, a composite sandwich core is not necessary to obtain structural rigidity as it would be for an ICE firewall.