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

If you're looking to significantly boost the performance of your 2001-2004 Chevrolet Silverado or GMC Sierra 2500/3500 with the 6.6L LB7 Duramax engine, this Wehrli twin turbo kit is a solid choice. This kit is designed to work with your stock IHI turbocharger as the high-pressure unit, paired with an S400 series turbo as the low-pressure unit, to create a compound setup. This configuration is capable of supporting up to 1000 rear-wheel horsepower, depending on your specific turbocharger selection and other fuel system modifications. It's a popular option for daily drivers and tow rigs that need more power, better fuel economy, and improved Exhaust Gas Temperature (EGT) control, all while maintaining a turbo spool that feels similar to stock.

Wehrli has put together a comprehensive package here, including a coolant overflow tank with all the necessary hoses, fittings, and a low coolant sensor. You'll also find silicone boots, T-bolt clamps, V-band clamps, and heat wrap to ensure a secure and well-insulated installation. The kit features an atmosphere turbo pedestal with an integrated oil return fitting, a 5-inch intake with a dry air filter and Outerwears pre-filter cover, and stainless steel oil feed and drain lines. It also includes a 3.5-inch cold side charge pipe, a 3.5-inch turbo inlet horn, a one-piece 3-inch Y-bridge with heavy-duty bead rolls, and a 4-inch ceramic-coated turbo downpipe. The cold side intercooler pipe is 3 inches, and the entire kit comes with a durable custom gloss black powder coat finish for a clean look.

While this kit is designed to work with your existing stock turbo, it's important to note that the S400 series turbocharger itself is not included. Wehrli recommends specific turbo combinations, such as an S475 or S480, depending on your horsepower goals and desired spool characteristics. For setups aiming for 750-800+ RWHP, a built Allison transmission is also recommended to handle the increased power. This kit is proudly made in the USA.