It should sound clean without mufflers as long as you incorporate a good X pipe. I have never actually measured the dB levels but you'll be gaining quite a bit. I have long tube tri-Y headers, x pipe and 2 straight through tanabe canisters and its mellow at idle but WOT sounds like an absolute beast. If your looking for the best sound as well as power gain, I would reccomend a Burns stainless X pipe. they make world class exhaust components. They arnt cheap but you will make some awesome gain with it.