FITMENT
- 2015.5-2016 6.6L Silverado & Sierra Duramax LML 2500HD/3500HD Diesel engine pickup.
- This downpipe features a 3-Bolt Flange connection at the turbo outlet.
- NOT fit 2011-2015.5 models that utilize the V-band style clamp connection.
DESCRIPTION
Product Overview
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The factory downpipe on Duramax LML trucks is a major performance bottleneck. To squeeze past tight engine bay clearances, GM engineers severely crushed and flattened the stock pipe.
- This restricted "pancake" design chokes exhaust flow, traps excessive thermal energy right at the turbo charger, and spikes EGTs under heavy towing loads.
- Upgrading to smooth, 3" mandrel-bent downpipe maximizes exhaust flow right from the turbo outlet, rapidly dropping EGTs and allowing the turbo to spool up much faster.
Key Features
- Premium T-304 Stainless: Computerized Mandrel-Bends and heavy-duty 16-gauge T-304 SS ensure maximum rust-resistance and structural strength.
- TIG-Welded Construction: All joints are precision TIG welded and jig-built to prevent cracking under high thermal cycling and aggressive vibration.
- Unrestricted 3-Inch Bore: Replaces the restrictive, "crushed" factory oval pipe with a true, consistent 3-inch mandrel-bent round diameter through every turn.
- Drastic EGT Reduction: Smooths out exhaust flow to quickly draw extreme heat away from the turbo, reducing under-hood temperatures and protecting engine longevity.
FAQ
Q: What are the main benefits of upgrading the late-LML downpipe?
A: The factory downpipe is severely crushed into a flat shape to clear the firewall. Replacing it with our true 3" round mandrel-bent pipe lowers backpressure and EGTs significantly, eliminating turbo lag while freeing up a deep diesel exhaust note.
Q: How do I tell if my truck needs the V-band or 3-bolt version?
A: Look at the turbo outlet. 11-15.5 trucks have a V-band clamp (hose clamp style, no bolts). 15.5-16 trucks have a 3-bolt flange (three bolts in a triangular pattern). Purchase as needed: 11-16 LML DPF/EGR Delete Kit.
Q: Does this downpipe require custom tuning?
A: If installed on a stock truck with all 2 factory sensors reinstalled correctly, no custom tuning is required and it will not trigger a Check Engine Light. If you choose to delete the sensors, an emission-delete tune is required.
Q: What exhaust should I pair with this downpipe to maximize performance?
A: Pair this downpipe wit LML DPF Delete Pipe or DP-Back Exhaust. While this pipe frees up the turbo outlet, the delete pipe eliminates the restrictive factory DPF/CAT downstream. Together, they create a fully unrestricted system that maximizes flow, slashes EGTs, and delivers a deep rumble with zero cabin drone.
