hey guys when i got my EL XR6 i got an straight through 2.5 sports exhaust put on with a hotdog resonator and my mate got the same setup as to mine on his futura and his sounded no way near as loud as my was. now for those who own EF-EL XR6's out there just wondering is there a difference in what muffler u get in the middle and is there any performance loss issues when having a quieter centre muffler?

i dont think you will lose any power going a quiter muffler, as going from a stock exhaust to sports cat back exhaust doesnt give you much power, its the extractors that will give you a power increase combined with a cat back

is there different center mufflers u can get for ur sports exhaust instead of a straight through one?

Depends on the brand of the exhaust, the center muffler, be it straight through, sports design, ect, was the resonator the same, you can get 12" 8" perforated and non perforated. The design of the exhaust how it was bent.
Weather or not you or he changed the cat convertor.
Xr motor will of course give you a nicer note.