Just put one on my fatboy along with a Mikuni 42. Runs much better down low. But had Vance big shot staggered without baffles. Seat of the pants dyno shows good improvement. I like the sound too, a little quieter and deeper. The big shots were LOUD, so are the big Radius but not as loud. And if you want louder take out the baffle. But watch the bottom end performance suffer some.