One of the more difficult issues that has come up is how to completely separate the fuel cell from the driver's compartment as described in the spec. It was my understanding that the fuel cell must be completely separated by a firewall but I've written the technical director at Vorra for clarification and his response shows a bit easier solution. So, in practice a smaller shield that is in front of the fuel cell and that has an angled back top that goes over the fuel cell as to direct any splashing away from the passenger compartment is considered OK. It looks like other potential racing sanctioning bodies would have the same requirements. BITD, BORR for future racing possibilities.
SRR: Fuel Systems Rear mounted fuel cell must have a chassis or body cross member and fire wall of
substance between the fuel cell and driver and be protected from ground obstacles.
A splash shield must be in place to direct any spill away from the driver, motor and
motor exhaust. A body panel is considered sufficient splash shield. Refer to SRR:
Firewall specification concerning fuel cell firewall construction.
Vorra Tech Director, "A firewall is recommended but not required. We would encourage some sort of enclosure to keep fuel out of the drivers compartment and please ensure all vent lines exit outside the vehicle. Typically the fuel vent would run from the cell around the top of the B hoop and out the bottom of the floor. For vehicles using the standard fill cap we require a secondary latch (or bungee cord) to make sure the cap can't come off from vibration."
A good vehicle / class to model this type of build from is the "Jeepspeed" Cherokees.
Hope this clarification helps!
-Eric
