topherserrano

They come with German HJS 200-Cell Cats that flow 90% the efficiency of Cat-less, however, still scrub the exhaust clean enough to not throw a CEL. I've got approximately 2,500 miles on my GMG Exhaust on my TTS and not a single hiccup. Quiet (almost stock-like) when in Normal mode, aggressive without being obnoxious when in Sport (most burbles and pops) and Sport+ driving normally. When you romp on it and give it the beans, the exhaust note becomes a complete banshee.

There is a little drone when cruising at around 2,000-2,300rpm in Normal Mode at highway speeds but is expected for any aftermarket exhaust. The drone is manageable with throttle input, I'd say.

Tumbleweed

With my GMG exhaust on my '21 TTS it was quiet when off the throttle but when you got on it the sound increased. It was not bad at all driving around town & on the highway unless you wanted it to.

topherserrano

I agree 100%, as that is exactly my experience as well. Easy driving on Normal drive mode is almost stock-like. Once you are WOT at 5,000rpm the sound is absolutely ferocious.

SB27

Glad the setup is working great for you. For my application, the volume of sound at startup, idle, partial power, cruising and full power were all overwhelming. As noted in my original post, I loved the wide open throttle sound -- simply amazing. You can also feel the car delivering more torque with this setup. No question it's faster. My wife was less excited about all of these things -- so back to OEM exhaust for me. YMMV, right? Mine sure did. Oh well. :-)

gmgracing

As the others have said, the system includes 200 cell cats, and there is minimal drone. Pease, feel free to reach out to us if we can be of more assistance!