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

If you're looking to significantly boost the performance of your 2001-2004 Chevrolet Silverado 2500 HD with the 6.6L LB7 Duramax engine, this Wehrli Custom Fab S400 Twin Turbo Kit is a solid option. This kit is designed to work with a stock IHI turbocharger as the primary, paired with an S400 series turbo as the secondary, and is capable of supporting up to 1000 rear-wheel horsepower with appropriate fuel system and turbocharger upgrades. It's a popular choice 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 characteristic that feels similar to stock.

This kit comes with many of the essential components to get your compound turbo setup installed. You'll find a coolant overflow tank with all the necessary hoses, fittings, and a low coolant sensor. It also includes silicone boots, t-bolt clamps, v-band clamps, and heat wrap for secure and insulated connections. The atmosphere turbo pedestal features a built-in oil return fitting, simplifying the oil routing. For intake, it includes a 5-inch intake with a dry air filter and an Outerwears pre-filter cover. The kit also features stainless steel oil feed and drain lines with fittings, a 3.5-inch cold side charge pipe, and a 3.5-inch turbo inlet horn. A one-piece 3-inch Y-bridge with an HD bead roll end is included for improved airflow into the engine, along with a 4-inch ceramic-coated turbo downpipe for better exhaust flow. This kit is finished in a durable Candy Teal powder coat and is made in the USA.

When considering turbocharger pairings, an S475 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 handle 800+ RWHP with supporting mods, though it sacrifices a bit of low-end spool. If you're aiming for 900+ RWHP, an S480 paired with a 64mm drop-in turbo is suggested, providing improved top-end power with moderate spool characteristics. For these higher horsepower applications, a built Allison transmission is recommended. Please note that this kit is not CARB approved and cannot be shipped to California.