This aFe POWER turbo downpipe is engineered to outflow and outperform the restrictive, factory downpipe on the 2011 - 2015 GM Truck with V8 - 6.6L (td) engine. The mandrel bent, stainless steel tubing offers smoother transition bends for increased airflow, delivering quicker turbo spool times. CNC machined V - band inlets and outlets ensure a factory style, 360 - degree sealing surface. Both inside and outside surfaces of the downpipe are ceramic coated to reduce EGT's even in the most extreme environments.