i knwo there was a thread on how the prochamber sucked, so i know im not the only one who thinks so. but i had the prochamber on for a eyar. It sounded to hollow and dronish. and it had no low end. a few days ago i put on an h pipe and im amazed with the low end i gained. i used to not be able to spin my tires from a roll. now my rear tires take a beating EVERYTIME i hammer it. even when the engine is hott. Im much happier with the sound too. I think the h pipe is way meaner. Im glad i switched. just my two cents.