Not sure myself there intense_ The Two Brothers have the cool dual can but my friend has the Akropovic full system on his R-1 and sounds sweet. It's quiet without being too annoying but as you get the revs up it just sounds more bad-***. I think with the 636 the high rpms will make it sound more like a formula one car!

 

That is how my Arrow is. Its nice and low key in the low RPM's once you rev it up its gets really loud. its got this nice kind of hollow pure type sound if that makes any sense.

 

Makes sense to me aszrael. I just want that race sound and quick response. Don't want it to sound whiney ( spelling ) has to sound like a mean green machine [sm=icon_rock.gif]