Aright guys so I have yet another " which one is better " question haha ... I currently have a FMF Gold Series Fatty pipe and Powercore ll silencer, but I've been lookin into the Bills Racing expansion chamber and silencer set up. How much of a difference, if any would there be between the two. Is the difference simply when/where the power kicks in ( high range/ vs. low range ) or is there a significant difference in power all together ? Thanks in advance for any and all feedback !