https://www.sharkwerks.com/exhaust/p4...
The Shark Werks valves exhaust for all 991.2 cars with PSE (and GTS)
The 2017+ 991.2 Carrera was an incredible step forward in terms of horsepower and torque, as well as chassis and suspension improvements. But as we heard from the exhaust when we first tested the car and from repeat customer feedback, it's just not sporty or loud enough for many people who are used to the rumble of a flat six.

To remedy this we've developed an exhaust system with maximum performance in mind. The system removes the factory muffler, but still enables the original Sport Exhaust valve switch to work by closing half of the exhaust system when the system is disabled. In the open mode, it's noticeably louder than the original PSE system and gives drivers more joyful turbo whistling sounds. Our exhaust sounds deeper and more exotic than the factory system, but still does not drone or have resonance at freeway speeds. You can still close the valve when you need to make a call or prefer the sound of your stereo.

When using Sport and more aggressive modes, you'll have more popping and burbles on overrun than before, but you can still tame this by using the Standard drive modes.
Our exhaust is made from CNC mandrel bent stainless steel in the USA, assembled by hand and built-to-order. It will only fit cars with the factory Sport Exhaust System and its center-exit tips. It re-uses the original exhaust tips and is compatible with the switching valve system. This exhaust was independently dynoed and results showed 21 HP to the wheels across all RPMs and about 18 lb-ft torque gains. The exhaust also removes about 12 pounds from the rear of the car.
The exhaust is emissions friendly in that it does not alter or remove the catalytic converter or header system on the car, and it will not trigger check engine lights. Installation time is typically about 2-3 hours and is completely reversible, with no cutting or welding required.

PLEASE NOTE: This exhaust only fits the 991.2 Base, S, and GTS models with the 3.0L turbo engine and the Porsche Sport Exhaust System. It does not fit the 991.1 3.4 or 3.8L cars, and it does not fit the 991.2 cars with the standard (non-Sport) exhaust system.