Optimize your diesel's performance with a non-restrictive aFe Atlas turbo downpipe. Engineered to outflow and outperform the restrictive OE down-pipe on your vehicle, they are designed with 3 in. mandrel-bent steel tubing offering smoother transition bends for low turbulence, increased airflow, and quicker turbo spool times. aFe Atlas turbo downpipes utilize factory mounting locations for true bolt-on performance and feature high-quality, OE-style V-band flanges for a complete 360-degree leak-free sealing surface. GM pipes are coated with a black finish and wrapped in high-temperature thermal header tape for better insulation, reducing EGTs and underhood temperatures.