Stocker S475 Twin Compound Turbo Kit

The Diesel Power Source Stocker S475 is a twin compound turbo kit engineered for 1988-1998 Dodge 5.9L Cummins 1st and 2nd generation trucks, specifically for 12V and 24V engines. This kit aims to improve performance by utilizing compound turbocharging, which spools faster than a stock turbo alone and reduces Exhaust Gas Temperatures (EGTs) by 250-350 degrees. The kit integrates the stock K1 HX35 HY35 turbo as the smaller, high-pressure turbo, paired with a Stocker S475 large turbocharger (75mm compressor wheel, 96mm turbine wheel, 1.32 A/R housing). This configuration is tuned for a horsepower range from stock up to 600 HP, offering an estimated 21% horsepower increase and 23% torque increase. The package includes a DPS high flow 3-piece, 2nd gen exhaust manifold with pre-tapped pyro ports, a complete air intake system with an air filter, silicone low-pressure charge pipe with a Kevlar/Nomex liner, polished intercooler pipe, cast hot pipe, flexible steel braided oil supply lines, dual stainless oil drain lines, an adjustable wastegate, and a 4-inch downpipe (with a note that the S475 turbo has a 5-inch outlet reduced to 4 inches). Installation notes specify that Cummins 12V and 24V engines require a transmission cooler relocation kit. For 2nd Gen trucks, head studs are highly recommended for boost pressures over 48 psi, and fire rings are recommended for pressures over 55 psi, as this system is capable of exceeding 55 psi. Additionally, 1st Gen compound turbo kits may require modifications to the intercooler charge pipe. This kit is compatible with 1989-1998 Dodge 5.9L 12V Cummins engines and 1998-2002 Dodge 5.9L 24V Cummins engines. The product description also mentions that a few modifications are made to the stock turbo, but these do not prevent its future use as a stock turbo.