The single largest flow restriction inside of the exhaust system is trapped inside of the exhaust system is the factory flex section, as seen in the video.
The Tork Motorsports high flow flex section is made with:
T304 materials
Welded with Helium shielding gas
Interlock flex section
3/8" thick flanges
Test results on the dyno were showing 7 to 11 WHP gains, where a full catless downpipe is showing 11 to 15 WHP gains. Affordable WHP gains with just the flex section upgrade.