I run a zippers high flow ac and a pc3 in my fatboy with a fatcat/standard baffle ,nice gains on the lower end. but the real key is a good tuner on the dyno
I also run hi flo filter with a pc3 with my fatcat and a good Dyno tune. The fatcat woke the bike up, but the dyno tune really woke it up. Hey guys, I can get the best prices on fatcats around. Email, PM, or call the shop and we will get you set up. We are one of the top retailers for D&D on the west coast. Another good option for tuning is the TTS , or the Zippers Thuidnermax with aurotune. Or...the dynojet power vision. I sell all of these at discounted prices every day as well.
NOTE: D&D has raised their prices for 2011 but we are still discounting deeply everyday for forum members.