What is considered a firewall? Fuel Cell mount question.

[PT Sportwagon]

I am thinking of putting a fuel cell in the rear trap door of the wagon. It is just empty space, ( right now is storage for a studded snow tire, LOL) I am wondering if the steel compartment lid would be concidered a fire wall in the eyes of some sanctioning bodies? like NHRA, SCCA etc. I was thinking of putting some stereo components there but I can use the spot where the factory fuel tank is.

Tim

[Twentyover]

SCCA

9.3.26. FUEL CELL SPECIFICATIONS
All cars must be equipped with a safety fuel cell....

a. There must be a metal bulkhead between the driver/passenger
compartment and the compartment containing the fuel cell.
This includes fuel cells that are flush mounted with driver/
passenger compartment panels or otherwise exposed to the
driver/passenger compartment.

Assuming by rear trap door you are refering to is a well behind the rear seat that would be the trunk floor on a sedan? If so, a metal plate (steel or aluminum) that covers the well where the fuel cell sits should be sufficient

[PT Sportwagon]

Sorry to bring this back up but I got to thinking again. The rear storage compartment is where the 3rd seat would be if so equipped. It is in the very rear of the wagon behind the rear axle. It is covered by a steel cover. but it is not air tight, being it is used for storage.

Tim

[sik68]

For what it's worth, I have learned that a trunk firewall has important implications for fire suppression system. If you're planning to do a gas suppression system that routes to the trunk, the governing bodies stress that the trunk is isolated not only for gasoline/fire purposes, but also so that you don't go over the allowable suppressant concentration in the cabin.

[Kenova]

Don't use aluminum.
Ask David Pozzi about his tractor.

Ken

[Twentyover]

Planning a firewall architecture is a time-consuming process. Many sites try to take shortcuts by installing a vendor firewall loaded with features that they might not need. In Part 1 of a three-part series, Carole discusses the importance of firewall architecture planning.

Is this series available somewhere?


Don't use aluminum.
Ask David Pozzi about his tractor.

Ken

Lots of cars use aluminum firewalls. A firewall is to slow fire movement from one side of the wall to the other, hopefully long enough for a fire bottle to be deployed. There's no way to guarantee fire will not move through a firewall. I'm going to suggest that Pozzi's own Lola probably has an aluminum firewall