Rev9Power Rev9_AC-004; 38mm Wastegate Dump Tube Set Product Details Project's 35mm / 38mm wastegate turbo dump tube & elbow " - Stainless steel dump tube & elbow - Allows for proper clearance in the engine bay - Allows you to redirect the hot exhaust gas from the wastegate towards the bottom of the engine which reduces the temperature inside the engine bay - When used with an external atmospheric wastegate, it makes a very distinct open wastegate sound when the air is released quickly. Professional installation only.