While the search to increase Duramax LLY/LBZ/LMM power usually leads to exhaust, intake, or tuner, one part that's often overlooked is the stock turbo downpipe. MBRP's downpipes replace this restrictive factory exhaust component with a direct-replacement that mounts between the factory turbo and the rest of the exhaust. These downpipes delivers more flow, fuel economy, and better performance output.