So I wanted to go stage 1 on my 07 ultra. First I get a pair of LaRosa downturn slip-ons. These are a real nice (nostalgic looking) muffler but they are loud,RUDE LOUD when you get on it. Unfortunately I lost considerable mid range acceleration. Next, my TFI arrives so the last part is get a K+N air filter. I install the TFI and drill 4 - 1.25 holes in the backing plate while the intake is apart ( this is what dealers are doing now instead of selling SE A/C). I made a set of lollipops (credit goes to Blackwell33 from another forum) using 2 - 3/4in washers welded onto 1/4 x 1in bolts. these are installed by drilling holes in the bottom of the mufflers and create some needed back pressure. Now I get the tfi adjusted, 3 3 4 4 seems to be best with this setup, and out to the highway I go. I am amazed as the personality of this bike has been woke up. Now she accelerates hard thru all gears and pulls great in mid range.The intake sounds like its sucking my leg in and with the lollipops, no more decel/ downshift popping, these pipes now have a nice deep rumble and I can hear my tunes again. With any luck I'll also have a cooler running bike.