High Flow Bundle Kit Stage 3 for 2017-2019 Duramax L5P Gloss White

The Stage 3 upgrade for 2017-2019 6.6L L5P Duramax Chevrolet Silverado and GMC Sierra 2500/3500 HD trucks combines the Stage 2 High Flow Bundle and 3.5-inch Down Pipe. This package increases air and exhaust flow for the turbo and engine, improving efficiency, throttle response, and turbo spool up. It eliminates weak points in the factory design that can cause power loss, boost leaks, and failures in high-performance applications.

The air intake features a high-flow fabricated intake pipe, intake horn, and air box enclosure with a dry filter assembly, replacing restrictive plastic factory parts. This significantly increases airflow to the turbo, improving horsepower, torque, and cooling intake temperatures by drawing cold air through the hood Ram Air duct and inner fender. It's constructed of 14 gauge aluminum with large 4-inch piping. The intake horn is over an inch larger than OEM, and WCFab observed a 25HP gain with their 4-inch turbo inlet when used with a Max Effort Tune.

The kit also upgrades the restricted 2-piece, resonator-equipped, 2.5-inch diameter driver (hot) side intercooler pipe and leak-prone 2-piece plastic/rubber passenger (cold) side pipe with WCFab's heavy-duty 3-inch diameter 1-piece Driver (Hot) Side and 3.5-inch diameter Passenger (Cold) Side L5P Intercooler Pipes. These are made in the USA from high-strength, 14 gauge aluminum tube. The 3-inch Driver Side pipe eliminates the OEM resonator and middle boot joint, including high-quality reinforced silicone boots and stainless t-bolt clamps. The 3.5-inch Passenger Side pipe features a CNC machined flange with a double o-ring seal and an upgraded silicone boot to withstand higher boost pressures.

On the exhaust side, a 3.5-inch Down Pipe replaces the restrictive factory part. It's black ceramic coated and heat-wrapped for thermal efficiency. It connects to the DOC (Diesel Oxidation Catalyst) outlet flange and mates with the OEM exhaust system front pipe with a 4-bolt style flange connection, including bungs for OEM sensors. Compatible with stock trucks (no tuning required), Stage 3 bundle kits pair best with emissions-compliant tuning and larger drop-in turbochargers. Installation is possible with basic hand tools.