If they are Cycle Shacks, they're very loud.
I use to modify CS's baffles, closing a kind of tongue in front of the baffle that causes gas partially direct flow, and adding 5" perforated pipe with a round plate back of the baffles to add a bit of silencing effect. Still loud but only at high revs.
You can do only with slash cut and slash down because on tapered and turnout the baffles are not extractable.
