Wehrli Custom Fabrication WCF100570-GM Duramax Compound Twin Turbo Kit - LB7 S400/Stock

The Wehrli Custom Fabrication S400/Stock Compound Twin Turbo Kit is a comprehensive performance upgrade designed specifically for 2001-2004 LB7 Duramax engines, capable of reaching up to 1000 RWHP depending on turbo selection and fuel system modifications. This kit is ideal for daily drivers, work trucks, and tow rigs seeking increased horsepower, improved fuel efficiency, and superior exhaust gas temperature control while maintaining stock-like turbo spool characteristics.

Key Features:

• 5-inch intake with dry air filter and Outerwears pre-filter cover
• 3.5-inch cold side charge pipe and turbo inlet horn
• 3-inch one-piece Y-bridge with heavy-duty bead roll end
• 3-inch cold side intercooler pipe with 14-gauge aluminum construction
• 4-inch steel turbo downpipe with high-temp black ceramic coating on hot side pipes
• Atmosphere turbo pedestal with built-in oil return fitting
• Stainless steel oil feed and drain lines with fittings
• Coolant overflow tank with hoses, fittings, and low coolant sensor
• Complete hardware including silicone boots, T-bolt clamps, V-band clamps, heat wrap and clamps
• Powder coating included in price with multiple color options available

Compound turbo configurations have become one of the most popular upgrades for the LB7 Duramax, providing cooler exhaust gas temperatures and increased power across the entire RPM range while retaining factory turbine brake functionality. Unlike larger single turbo upgrades, compounding over the factory turbocharger eliminates additional turbo lag, delivering instant response and boost with improved efficiency.

Performance Options:

• S475 with stock IHI turbo: Up to 750 RWHP with excellent spool and performance on stock fuel systems
• S480 with stock IHI turbo: 800+ RWHP with enhanced top-end performance

Every WCFab turbo kit is hand-built in-house by experienced fabricators, with all components built and test-fitted on jigs to ensure proper fitment, featuring TIG-welded tubing and CNC-machined flanges with O-ring seals for a boost-leak free setup. Note: This kit requires removal or relocation of the passenger side battery to accommodate the turbo setup. Proper tuning and upgraded fuel delivery system recommended for optimum performance and drivability.

Note: This product cannot ship to the state of California.