2017-2023 6.6L CHEVY L5P DURAMAX DIESEL 3.5'' DOWNPIPE EXHAUST

iFJF part No.: DP-0170. Reference: UNKNOWN 2500HD3500HD. 3.5" High-Flow Turbo Downpipe for 2017-2023 Chevrolet/GMC 6.6L Duramax L5P Turbo Diesel Replace the restrictive factory downpipe on your 2017-2023 Chevrolet Silverado or GMC Sierra 2500HD/3500HD with the 6.6L Duramax L5P Turbo Diesel using this mandrel-bent 3.5" downpipe. The OEM downpipe is one of the most restrictive components in the L5P exhaust system, featuring a pinched cross-section designed to clear the firewall that severely limits exhaust flow. Our 3.5" mandrel-bent downpipe eliminates this bottleneck for dramatically improved turbo response, lower EGTs, and increased power. Why Upgrade Your L5P Downpipe? OEM Restriction: The factory L5P downpipe uses a flattened, ovalized design to clear chassis components this creates significant backpressure right at the turbo outlet where flow matters most. True 3.5" Mandrel-Bent Flow: Our downpipe maintains full 3.5" internal diameter from the turbo V-band flange all the way to the exhaust connection zero flow restriction. Lower EGTs: Free-flowing exhaust at the turbo outlet reduces exhaust gas temperatures by 50-150 F, critical for towing heavy loads up long grades. Faster Turbo Spool: Reducing backpressure allows the VGT turbocharger to spool faster, improving throttle response and reducing lag. Foundation for Future Upgrades: The stock downpipe becomes the limiting factor after any performance tuning. Our 3.5" downpipe supports 600+ HP builds. Vehicle Compatibility Year Make Model Engine 2017-2023 Chevrolet / GMC Silverado 2500HD / Sierra 2500HD 6.6L Duramax L5P V8 Turbo Diesel 2017-2023 Chevrolet / GMC Silverado 3500HD / Sierra 3500HD 6.6L Duramax L5P V8 Turbo Diesel Premium Build Quality T409 Mandrel-Bent Stainless Steel: Consistent 3.5" diameter throughout no crush bends, no diameter reduction, no flow restriction. V-Band Turbo Flange: Precision CNC-machined V-band flange ensures a perfect, leak-free seal at the turbocharger outlet. OEM Hanger Points: Pre-welded hanger brackets use factory exhaust hanger locations for true bolt-on installation. Corrosion-Resistant: T409 stainless offers excellent durability in all climates, road salt exposure, and under-hood heat cycling. Performance Benefits +10-20 HP / +20-40 lb-ft Torque: Eliminating turbo outlet restriction frees significant power. 50-150 F Lower EGTs: Critical for safe towing temperatures on long grades. Faster Turbo Spool: Immediate improvement in throttle response and reduced turbo lag. Deep Exhaust Tone: Fuller, deeper turbo diesel exhaust note. Supports High-HP Builds: Flows enough for 600+ HP with supporting modifications. Installation Overview This downpipe is designed for bolt-on installation using factory mounting points. The turbo-side connection uses a V-band clamp (included). Estimated installation time: 2-4 hours with basic hand tools, a floor jack or lift, and moderate mechanical experience. Access to the turbo outlet requires working from underneath the vehicle. No welding required. Frequently Asked Questions Q: Will this fit my 2022 Silverado 3500HD L5P? A: Yes. This downpipe fits all 2017-2023 Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD models with the 6.6L Duramax L5P engine. All cab configurations (Regular, Double, Crew) and bed lengths are supported. Q: Can I install this without a tune? A: Yes. The downpipe itself does not require tuning and will not trigger a check engine light when installed on its own. However, for maximum perform