Wehrli 01-04 Duramax LB7 Twin Turbo Kit S400/Stock - Semi-Gloss Black

Wehrli Custom Fabrication is known for building robust performance parts for Duramax trucks. This twin turbo kit is designed for the 2001-2004 Duramax LB7 engine, offering a significant upgrade over the stock setup. It's built to handle up to 1000 rear-wheel horsepower, depending on your fuel system and turbocharger choices, making it a solid option for daily drivers and tow rigs that need more grunt. You can expect improved horsepower, better fuel mileage, and superior Exhaust Gas Temperature (EGT) control, all while maintaining turbo spool characteristics similar to stock.

This kit includes everything you need to get started, featuring a coolant overflow tank with all necessary hoses and a low coolant sensor, plus silicone boots, t-bolt 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 Outerwears pre-filter cover, and stainless steel oil feed and drain lines. You'll also get a 3.5-inch cold side charge pipe, a 3.5-inch turbo inlet horn, a one-piece 3-inch Y-bridge with a heavy-duty bead roll, and a 4-inch ceramic-coated turbo downpipe. The cold side intercooler pipe is 3 inches, and the entire kit features a durable custom semi-gloss black powder coat finish. This kit is made in the USA.

When choosing your S400 turbo, consider your goals. An S475 paired with the stock IHI turbo is recommended for up to 750 RWHP with supporting modifications, offering the best turbo spool and performing well on stock fuel setups. For more top-end performance, an S480 with the stock IHI turbo can achieve 800+ RWHP with supporting modifications, though it sacrifices a bit of low-end spool. If you're aiming for 900+ RWHP, an S480 with a 64mm drop-in turbo offers improved top-end power with moderate spool characteristics. For all these combinations, a built Allison transmission is recommended.