It will be louder as mentioned, but even my truck without a cat or muffler isn't that loud. I mean it's not headers and 3" exhaust loud at least to me... the turbo quiets some of the noise.

68 Road Runner, 69 Belvedere, 71 Challenger Vert
340 barracuda, 01 Ram CTD, 95 Ram, 04 Ram, 85 Daytona turbo Z
66 GTO, 06 Magnum RT AWD. 07 Ram CTD, 07 Ram