The WCFab Stage 2 upgrade for the 2011-2016 LML 6.6L Duramax Diesel Chevrolet Silverado or GMC Sierra 2500 / 3500 HD truck combines our Stage 1 High Flow Bundle and Stage 2 Cold Air Intake Kit into a single package providing increased airflow for your turbo and engine for improved efficiency, throttle response, and turbo spool up. This kit eliminates weak points in the factory design that can contribute to lost power, boost leaks, and complete failures in hard-working and high-performance applications.

The high-flow, fabricated aluminum intake pipe and air box enclosure with dry filter assembly replaces the restrictive plastic factory parts on your diesel for improved engine performance. The new design significantly increases airflow to your turbo, producing improved horsepower and torque, quicker throttle response, and cooler intake temperatures by drawing cold air through the inner fender. All aluminum construction features large diameter 4" piping with smooth aerodynamic bends to improve intake air velocity volume and provide more aggressive engine and turbo sound during acceleration. High-quality hardware, silicone boots, seals, and stainless steel t-bolt clamps ensure optimum durability and ease of installation. Removable air box lid element allows for easy visual inspection and maintenance of your WCFab filter with included hydrophobic pre-filter cover to help keep your MAF sensor, turbo, and engine airways contaminant free.

Our High Flow 4.8 in. Cast Aluminum Turbo Intake Horn removes restrictions in the OEM setup to improve turbo spool and top-end power and eliminates factory resonators for improved appearance and more aggressive turbo sound. This High Flow 4.8 in. horn is fully compatible with OEM and upgraded drop-in VGT style turbochargers.

The 3" High Flow Driver (Hot) Side Intercooler Pipe replaces the factory two-piece 2.5” pipe with a high flow 3" pipe. The 3.5" High Flow Passenger (Cold) Side Intercooler Pipe replaces the factory plastic two-piece pipe with a high flow, 14 ga. aluminum one-piece 3.5" pipe. Includes upgraded silicone boots to withstand higher boost pressures than the factory components to increase reliability and eliminate blown factory boots and horsepower-robbing boost leaks. 

The LML Y-Bridge Kit finishes off the assembly replacing the OEM upper intake manifold supplying air to the engine intake runners and cylinder heads. The OEM Y-bridge for these trucks is a restrictive part that creates a bottle neck in the air intake tract and limits engine performance potential. This kit includes our high flow, precision CNC machined, cast aluminum precision intake bridge (40% more airflow than stock) together with a unique, 20% larger than stock, 3" fabricated aluminum upper crossover intercooler pipe that allows you to take full advantage of the larger inlet diameter of our Y-Bridge. The combination improves total air flow by 33% over the stock setup using providing maximum airflow volume for the available space.

This means you get the most out of your engine in terms of performance and efficiency. Incorporates factory intake air heater grid for superior cold weather performance. Eliminates the stock plastic resonator for improved engine bay appearance and more aggressive turbo and engine sound. Compatible with OEM throttle valve and EGR controls.

Finished in your choice of custom powder colors. This product is compatible with stock trucks requiring no additional modifications, upgrades, or tuning for installation. Pairs best with emissions-compliant tuning and drop-in turbochargers for optimum performance gains.