Wehrli 01-04 Chevrolet 6.6L LB7 Duramax S400 Twin Turbo Kit (No Turbo) - Bengal Blue

If you're looking to significantly boost the performance of your 2001-2004 Chevrolet Silverado or GMC Sierra with the 6.6L LB7 Duramax engine, this Wehrli Custom Fabrication S400/Stock compound turbo kit is a serious upgrade. This kit is designed to work with your existing stock turbo and add a larger S400 series turbo, creating a compound setup that dramatically increases horsepower and torque. It's a popular choice for daily drivers and tow rigs that need more power while also improving fuel mileage and keeping Exhaust Gas Temperatures (EGTs) in check, all with a turbo spool that feels surprisingly close to stock.

This kit is built to handle up to 1000 rear-wheel horsepower, depending on the specific S400 turbo you choose and your fuel system modifications. Wehrli includes everything you need to get the compound setup installed, except for the S400 turbo itself. You'll find a coolant overflow tank with all the necessary hoses and a low coolant sensor, silicone boots, t-bolt and v-band clamps, and heat wrap. It also comes with an atmosphere turbo pedestal that has a built-in oil return fitting, a 5-inch intake with a dry air filter and an Outerwears pre-filter cover, stainless steel oil feed and drain lines, a 3.5-inch cold side charge pipe, and a 3-inch one-piece Y-bridge with a heavy-duty bead roll end. The kit also features a 4-inch downpipe with a ceramic coating for better heat management and a 3-inch cold side intercooler pipe. The durable custom powder coat finish in Bengal Blue not only looks great but also adds a layer of protection.

Wehrli offers several recommended turbo combinations to pair with this kit, such as an S475 or S480 for up to 750-800+ RWHP with supporting mods, or an S480 with a 64mm drop-in turbo for over 900+ RWHP. For these higher horsepower applications, a built Allison transmission is recommended. This kit is proudly made in the USA and is not CARB approved, so it cannot be shipped to California.