Porsche 991 turbo s exhaust

The loudest for a Turbo: Cat & Muffler delete. Run straight pipes with 02 sensors. Local muffler shop can accomplish. A Turbo engine is not that loud to begin with. Running straight pipes is easy, not expensive. HP increase could be as high as 100 HP. A custom exhaust on my turbo increased the HP by almost 100. My X50 is 525 to the ground. 600 to the crank with 571 ft lbs of torque. -Good luck-

Depends on the money you have (assuming it's no object based on the year of the car) BBi Autosport exhaust or Meisterschaft Super GT Exhaust are pretty radical sounding--- In my case I joined the left and right side exhausts into a 180* X pipe without a muffler and it sounded tits (in a turbo application you're going to want hi-flo cats) https://www.youtube.com/watch?v=wBzd-IP69TY