Boosted Performance 3-Inch Downpipe (11-16 6.6L Duramax Sierra 3500 HD)Find parts that fit my vehicle

The factory downpipe is the most restrictive portion of the LML's exhaust system. The restrictive design results in excess exhaust backpressure which impacts the turbos ability to spool freely and increases exhaust gas temperatures. Upgrading to a larger 3" exhaust system will drastically reduce backpressure and therefore increase turbo efficiency which results in more horsepower and torque, lower EGTs, and a healthier turbo and engine. An upgraded downpipe is a great mod for stock LML's but is even more important for tuned diesels that running higher than stock boost levels as the backpressure reduction helps the turbo spool with less restriction, reducing stress on the turbo and improving spool efficiency.

Our larger 3" LML Downpipe flows significantly more than the factory pipe, resulting in a freer flowing exhaust system that maximizes performance and backpressure reduction. It is a direct bolt on fitment for all 2011-2015.5 models and doesn't require any tuning or additional modifications. 

Note: this downpipe does not fit the 2015.5-2016 models that have the 3-bolt flange that connects the bottom of the downpipe to the rest of the exhaust, it only works with the earlier v-band flange. 

Duramax LML Downpipe Upgrade Benefits:

_x005F_x000D_
• -Horsepower and torque gains (est. 10-20whp and 20-30wtq depending on tuning and mods)
_x005F_x000D_
• -Reduction in exhaust backpressure
_x005F_x000D_
• -More efficient turbo + increased turbo reliability when tuned
_x005F_x000D_
• -Lower EGTs
_x005F_x000D_
• -Overall healthier engine
_x005F_x000D_

Our performance downpipe will not add any material sound gains. If you want a louder exhaust system we recommend getting a 4" or 5" emissions-back exhaust system which is also beneficial for increasing exhaust flow. While a downpipe doesn't provide the sound gains it does provide more performance gains and engine benefits compared to an exhaust system. 

Boosted Performance Downpipe Features:

_x005F_x000D_
• -3" design for maximum flow
_x005F_x000D_
• -Stainless steel, no rusting or corrosion
_x005F_x000D_
• -Direct bolt-on fitment (v-band style only)
_x005F_x000D_
• -No tuning required
_x005F_x000D_
• -Includes heat wrap to prevent heat transfer
_x005F_x000D_
• -O2 bungs fit factory sensors or can be plugged
_x005F_x000D_

CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov