Here is an idea I had for the stock touring air box. I got the idea from a guy named "Turbo Tom" who has a performance bike shop in Orange County, CA. He did the same thing for the Honda ST1300 and everyone who did it claimed a power increase. Our air filters have the same size opening at the top and bottom. The bottom sits on the bottom of the air box with no opening. I pulled the air filter out and found there is a raised ridge to seal the foam ring on either end of the filter at the bottom of the box. In the middle is a flat surface with a drain tube. I took my flashlight and looked under the bike to find the bottom of the air box sits above the starter unobstructed. So, using a 2 1/2" hole saw, I made two holes in the bottom of the air box between the hole on the bottom of the air filter. One at each end. I then took a hot knife and trimmed the middle section between the holes out, creating a perfect match for the bottom of the air filter opening. The raised edge still seals the bottom of the air filter, but I now have an air inlet at the bottom that is the same size as the air inlet at the top. This has to add air flow to the bike. I have included some pictures for reference.