Dude, im tellin ya, get Glasspacks. I had the 40 series and my best friend has the Magnaflow Cyclone on his. I got my Glasspack and it sounds a ton better than the 40 series, the Magnaflow sounds good but I just needed something really loud!!!! If u want loud and deep sounding(not ricy) get glasspacks, if u want not so loud but still sounds good get Magnaflow.