Wehrli 11-16 Duramax LML High Flow Bundle Kit Stage 2 - Illusion Blueberry

Wehrli Custom Fab built this Stage 2 High Flow Bundle Kit to replace every restriction point in the 2011-2016 Duramax LML intake and intercooler system. Finished in their Illusion Blueberry powder coat, it covers the Chevrolet Silverado 2500 HD and 3500 HD and addresses the known weak points that limit airflow and cause boost leaks on hard-working trucks.

The intake begins with a 4-inch aluminum pipe and 10-gauge aluminum air box housing a dry filter for easy servicing. Wehrli's 4.8-inch cast aluminum turbo intake horn eliminates the factory resonator, improving turbo spool and adding a more aggressive intake sound. It works with both the stock turbo and upgraded drop-in replacements. Cold air feeds in through the inner fender, keeping intake temperatures down under load.

Both intercooler pipes are completely replaced. The 3-inch driver-side hot pipe flows 18% better than the factory 2.5-inch two-piece unit, while the 3.5-inch one-piece passenger-side cold pipe flows 23% better than the stock plastic assembly. Each pipe is made from 14-gauge aluminum with silicone boots and stainless T-bolt clamps at every joint.

The cast aluminum Y-bridge rounds out the kit with a 33% improvement in total airflow over stock. It pairs a 40% larger upper intake manifold with a 20% larger 3-inch crossover pipe, directly addressing the bottleneck that the factory bridge creates. The design retains the factory intake air heater for cold weather use and stays compatible with the OEM throttle valve and EGR system. Everything bolts on with no modifications or tuning required.