2017-2023 Chevrolet Silverado & GMC Sierra 2500 3500HD L5P 6.6L Duramax Diesel 3.5" Downpipe Exhaust GenericProduct Overview: The downpipe channels exhaust gases from the turbine housing into the exhaust system. Upgrading to a performance downpipe with a larger diameter and high flow design reduces restriction and boosts exhaust flow. By eliminating the factory limitations, this downpipe allows the turbo to expel gases more efficiently, resulting in improved power output, quicker spool times, and the ability to safely increase boost pressure.