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LML Duramax Downpipe

-3" downpipe upgrade
-Direct bolt-on, no tuning needed
-Horsepower & torque gains
-Lower EGTs
-Reduced exhaust backpressure
Availability: In-stock, ships within 1-business day
NOTE: This product has the following shipping restriction(s):
  • This product is not available for shipping to California
Pricing: $249.00

NOTE: This product has the following shipping restriction(s):
  • This product is not available for shipping to California
Free Ground Shipping Within The Continental US


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:

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

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:

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



Shipping Information

  • Item Requires Shipping
  • 7.0 lbs.
  • W7.0000” x H5.0000” x L24.0000”
  • Free Ground Shipping Within The Continental US

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