aFe MACH Force-Xp 3in 409 Stainless Steel Down-Pipe 11-15 GM Diesel Trucks LML V8 6.6L (td)This aFe POWER turbo down pipe is engineered to outflow and outperform the restrictive, factory down pipe 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 down pipe are ceramic coated