ATL Fuel Cell, Wires and Pumps- SAE 30 R10?

Did you ever wonder what's inside those fuel cells made by companies like ATL that you see in almost all racing cars? I know that I just assumed it is "full of some foam or something" and left it at that. Well, if you don't happen to have a fuel cell handy, let me tell you what's really living inside of that shiny metal box.

My friend Ed over at Perfex Manufacturing  has a pretty cool Porsche 928 race car that needed a new fuel cell to be ready for the 2012 season. I spoke with the very helpful staff at ATL and decided to order the direct replacement for the old unit. You can also have it made up with all of the fittings, pumps and wiring, but that kinda takes the fun out of the whole project. I ordered our unit from my friends at Stable Energies and had it in a few days.

Here's the foam that we removed from the new cell. Once the top plate is off, these blocks can be carefully removed from the bladder. Oh yeah- the box is really just a container for a heavy duty rubber lining that contains the foam that absorbs the fuel. So in this application, there will be three fuel pumps and their associated wiring and piping inside of the foam and connected to the top plate. 

Yes-wiring inside of the fuel tank sounds a bit odd, but hey- everybody is doing it. I was careful to cut out pockets in the foam for the fuel pumps and channels for the wiring and high pressure hose. You can buy special submersible fuel hose, but it's super expensive, and it turns out that 300PSI  hydraulic hose is OK too- that's what comes in the cell from the factory. Once everything was arranged and wired, I placed the foam blocks and components back in reverse order, triple checking all connections and fittings. Once this thing has fuel in it, it would not be fun to do any adjustments later.

Here's the new unit sitting in it's frame in the rear floor- Ed fabricated some nice hold down brackets not shown here, and we added a new filler neck to clean the installation up. I used Weatherpack 2 and 3 pin sealed connectors to make the electrical connections reliable and robust enough to carry the current draw of the three pumps.They're also easy to disconnect for service later.

So there's a lot more than fuel and foam inside a fuel cell- it's a very important part of the fuel delivery system and requires careful handling, assembly and attention to detail. The next question is, can I really just splice in to the existing wiring in this car ?