I was going to ask about the race fuel too. Unless you are set up to run high compession, etc. A high octaine fuel isn't going to do anything but drain your wallet faster. I run no airbox, with a foam filter, it is pretty well up and out of the way, and I use a pre filter. I ride dirt, but I avoid deeper water crossings and excessive mud because of my filter. I personaly would prefer a K&N in the box with no lid as opposed to the set up I have now, just less to worry about.