Wehrli Custom Fabrication WCF100775-FB High Flow Cast Turbo Intake Horn Flat Black

The Wehrli Custom Fabrication WCF100775-FB High Flow Cast Turbo Intake Horn is a precision-engineered, bolt-on upgrade designed to maximize turbo inlet airflow on the GM 6.6L Duramax L5P diesel engine. Finished in a durable Flat Black powder coat, this USA-made intake horn delivers a 27% improvement in airflow over the factory unit, with a 25% greater flow area at the compressor inlet — making it one of the most effective single-component airflow upgrades available for the L5P platform.

Key Features:

• Flows 27% better than stock for improved turbo spool-up and increased horsepower
• True 4" inlet with a smooth, flowing transition to a strategically designed anti-surge face that properly engages the turbo compressor cover
• 25% greater flow area than OEM at the compressor inlet
• CNC machined cast aluminum construction for strength and precision fitment
• Compatible with factory VGT turbochargers and OEM-style aftermarket drop-in turbos with larger compressor wheels
• Includes a #10 ORB threaded billet aluminum hose barb for PCV connection
• Sealed with an O-ring at the turbocharger face for a leak-free connection
• Includes all necessary mounting hardware and gasket — no tuning required
• Flat Black powder coat finish (WCF100775-FB)
• Made in the USA

Installation is straightforward: disconnect the batteries, remove the factory intake tube, resonator box, and OEM intake horn, then install the WCFab horn onto the turbo housing studs and torque to factory spec (18 ft-lbs / 25 Nm). Reconnect the PCV line to the included threaded bung and reinstall the airbox. No additional modifications or engine tuning are required. The WCF100775 carries a 1-year manufacturer warranty.