Firewall construction

[spdunlap]

Would a firewall constructen of Kevlar and layments of steel or aluminium be legal? Is it considered a firewall or a hard stop for the engine should it come loose?

[SR Racing]

Here is all I can find on the Firewall. Sounds like a steel or alum / kevlar laminate would be legal.

9.1.1 J "A firewall to prevent passage of flame and debris between the engine area and driver’s compartment shall extend the full width of the cockpit and be at least equal to the top of the carburetor in vertical height."

Appendix B. "Firewall - A vertical (plus or minus ten (10) degrees) metal panel separating
and protecting the driver/passenger compartment from the engine
compartment, preventing the passage of flame and debris."

[hardingfv32-1]

The driver is as likely as the engine to come loose, both are pretty much unheard of. A laminate using fire resistant resin would do fine for the firewall and could be designed to handle the intrusion requirements. Nothing in the rules says it must remain undamaged. How long any firewall has to resist a fire is a question mark.

With both the engine intrusion and firewall rules, what you must concern yourself with is how is your design going to be perceived by Tech. You cannot rely on the Tech inspector being an engineer or composite specialist. You have to present something that is in their comfort zone.

Brian

[vreihen]

I always wondered about the firewall rules when looking at most Vees that I see showing up at Solo events in these parts. The firewall is supposed to stop the spread of flames, and yet the carburetor (where a fire is likely to start) is above the firewall and behind the driver's neck. Some even have ducts/scoops to blow carb fire flames out at the driver's head! Makes about as much sense as an 8-foot tall Wookie on the planet Endor with 2-foot tall Ewoks. I guess that it really isn't a big concern in cars with the engine behind the driver, since the fire will blow backwards as long as the car is moving forwards.

The SCCA Solo rules do not specify minimum thickness or materials for a firewall, but do have specifics on scatter shields for drive train explosions. I take it from other posts in this thread that GCR offers no further guidance in this regard?????

[fv87]

I used this as a guidline. If it's thick enough to protect the fuel cell, wouldn't it be good enough for a firewall?

Sports Racing Category and Formula Cars
The fuel bladder shall be completely surrounded by a container
(which may also be a part of the structure or bodywork of the
car) to ensure rigid and secure mounting of the bladder and
provide additional protection. A minimum of .036 inch steel,
.059 inch aluminum, or an approved equivalent is required for
all vehicles.