Both are based on DynoMax's well known fully-welded Ultra Flo architecture, which has a patented continuous straight-through perforated flow-path tube surrounded by continuous roving fiberglass.

The DynoMax Ultra Flo system fits like a glove, and the tailpipes have that sweet, polished OE look to them (only larger). It's a shame you can't put your ear to the page and hear the sweet ...

DynoMax's other option is the Ultra Flo Welded muffler (formerly named the Race Magnum), which delivers a more authoritative exhaust note than the Ultra Flo SS.

The new muffler-engineered to deliver the DynoMax's trademark "Drone-Free Performance"-offers the flow characteristics of the legendary DynoMax Ultra Flo welded muffler, through a straight-through ...