Careful...I installed some fairly open mufflers on my Virago 1100 a few years ago. It ran right at sea level, where I live, but above 5000 feet in elevation, it began to run rough...missing badly. I continued on, made it all the way up Pike´s Peak, regardless of its´ profuse sputtering and not being able to go very fast, but I made it up to the 14,740 or something feet elevation. Once getting below about 5000 feet it cleared up and was no longer problem. There was no apparent damage, tho it sounded like it was about to die. Rode it a few years more. If you don´t plan on riding to high elevations, a louder muffler may be OK. I like the extra noise too. Maybe it irritates some, but I´d rather drivers be irritated rather than not know I am there and run me over.