Ok, I just want to ask the experts of what aftermarket muffler I should install that will increase the bottom end and not have to be remapped running stock ecm and stock air cleaner. I have read the longer the muffler is is the best for keeping bottom end power, I never take it above 100 so I do not need the top end help, but I would like to increase bottom end if it is possible. I just do not know who makes the best and longest aftermarket for my. 2006 xb12x.