---tab Description--- This 3.5" turbocharger downpipe will increase exhaust flow, improving performance. Made with mandrel-bent 3.5-inch stainless steel tubing and coated in a ceramic black finish, this SPELAB high-performance L5P downpipe significantly improves airflow, reduces EGTs, and enhances turbocharger response. It’s the ideal component to begin building a full L5P Duramax downpipe delete system. Whether you're replacing a restrictive stock pipe or upgrading for tuning purposes, this Duramax downpipe delivers the gains you expect in both performance and durability. Specifications Application: Downpipe ExhaustMaterial: Stainless SteelSurface: Mirror Polish Key Features Complete Kit: Includes downpipe, heat wrap, clamps, and precision flanges Superior Heat Control: Minimizes heat soak and improves turbo efficiency Direct Fit: Designed to replace the 2018 L5P downpipe without cutting or welding Ceramic Coating: Sleek finish with high resistance to corrosion and heat OE vs. SPELAB Downpipe Comparison Feature Stock Downpipe SPELAB 3.5" Downpipe Pipe Diameter Narrow, restrictive Large 3.5-inch high-flow mandrel bent Surface Protection Bare metal, prone to rust Black ceramic coating, high-temp and anti-corrosive Weld Quality Spot-welded, uneven Precision full TIG-welded flanges Heat Management None Includes thermal wrap + stainless clamps Flow Efficiency High backpressure, turbo lag Smooth, unrestricted flow—ideal for L5P downpipe delete builds What's the Difference Between a Downpipe and an Exhaust? Component Function Description Location Downpipe Connects turbo outlet to mid-pipe; manages hot gas flow Immediately after the turbocharger Exhaust System Mid-section to tailpipe; reduces noise and handles emissions From downpipe to tailpipe Upgrading the downpipe = performance and throttle responseUpgrading the exhaust = tone, flow, and backpressure control ---tab Fitment--- 2017-2024 Chevrolet Silverado & GMC Sierra 2500 & 3500HD 6.6L Duramax pickup trucks. Will not fit Cab & Chassis trucks. ---tab FAQ--- What does a downpipe do? The downpipe on your turbocharged vehicle is directing the exhaust gases out of the turbine housing into the exhaust system. An aftermarket downpipe will typically be larger in diameter and either uses a high-flowing catalytic converter or remove the catalytic converter altogether. By removing the factory downpipe and replacing it with a high flowing unit you are allowing the turbo to more efficiently move gases away from the turbine which creates more power. Since the factory restrictions are now gone you can increase the boost on the vehicle as the factory downpipe is a choking point for performance. Q1: Is this SPELAB downpipe catless or catted?A: This is a catless downpipe, meaning it does not contain a catalytic converter. It’s designed for maximum exhaust flow and performance—ideal for off-road and race-use L5P Duramax downpipe delete builds. Q2: What is the difference between a catted and a catless downpipe?A: A...