A Tank And A Cat

01 Dec A Tank And A Cat

Today’s title may not make immediate sense, but it will by the end of the article. Promise.

Half of the title we can explain right off the bat. The long-term project Audi RS6 (currently north of 650 bhp) was having some fueling issues relating to the surge tank we designed for it a while back. The easiest solution for this problem? Build a larger surge tank. But that’s easier said than done. The first tank fit into the area just in front of the spare tire well, and while that’s fine, there isn’t room for a larger tank in there:

So we set about finding a place near the gas tank for a larger surge tank. Within a few inches of our old location, we found it. There’s a cavity at the bottom of the spare tire well, so we fabbed up a cardboard prototype of the size tank we needed, and guess what — it fit perfectly.

So we went about cutting the pieces of aluminum that form the top, bottom and middle of the tank. We also cut and then hand-bent the walls on either side of the flat planes that make up the top, bottom and middle. Pay attention to the first picture after this paragraph. It’ll come back later in the post. After everything was cut, we tacked it all together to get it ready for fitment; we also drilled the holes in the sides and bottom to account for the A/N fittings we’ll be attaching.

After some more welding, a quick test fitting and application of the A/N fittings, everything was looking good. So we set about welding everything together, created a small arm to hold onto the fuel pump (that bolts to the end of the rear differential), and hooked everything together. And it’s definitely looking like an improved model over the prior surge tank.

As we were cutting this piece, a few different names came up to describe it. Craig was especially pissed when we considered permanently naming it the “Hello Kitty Tank.” In an effort to find a more common ground, the FMU crew dug deep into their knowledge of internet memes and came up with something better — Nyan Cat Tank. For those of you unaware of Nyan Cat, check out the link to Wikipedia embedded in the previous sentence. Now that you know, the following image may make a bit more sense. Or it may not. But it definitely cements the name of the fuel surge tank for eternity, or so we’d like to think: