Wehrli Custom Fabrication WCF100412-GM High Flow Turbo Intake Horn LBZ LMM Duramax

The Wehrli Custom Fabrication WCF100412 High Flow Turbo Intake Horn is a precision CNC machined cast aluminum upgrade designed to replace the restrictive OEM plastic turbo inlet on LBZ and LMM Duramax engines. With a 4.8-inch inlet diameter — the largest intake horn available for this application — this horn delivers a 20% improvement in airflow over stock, resulting in improved turbo response and overall engine performance.

The cast aluminum construction eliminates the factory resonator for a more aggressive turbo and engine sound, while a retained PCV port ensures a complete, clean installation. The horn seals with an O-ring and connects to your intake pipe via a silicone reducer boot and stainless steel T-bolt clamps — all included. Each unit is finished in a custom powder coat color of your choice and proudly Made in the USA.

Key Features:

• 20% improvement in airflow vs. stock OEM inlet
• 4.8-inch inlet diameter — largest intake horn on the market for this application
• CNC machined cast aluminum construction
• Includes PCV port for clean, complete installation
• Eliminates factory resonator for improved appearance and more aggressive sound
• Includes silicone reducer boot, stainless steel T-bolt clamps, and O-ring seal
• Custom powder coat finish available in multiple colors
• Made in the USA
• Supersedes WCF100341
• Replaces GM OEM Part Number: 98011738

Compatibility Note: This intake horn requires an intake pipe that uses a separate silicone boot and two clamps for connection. It is not compatible with OEM or aftermarket intake systems (such as K&N) where the rubber boot connection is molded directly to the intake pipe. If your intake uses a boot-and-clamp style connection, this horn will fit. Designed to complement WCFab Stage 1 LBZ and LMM Intake Kits.