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We offer complete compound turbo kits for ‘01-‘16 Duramax trucks. Built by Wehrli Custom Fabrication, these top of the line kits use an S400 based charger as the atmospheric unit and retain your stock turbo as the high pressure unit. These systems have been proven to support well over 700 hp and 1200 lb-ft of torque with proper tuning. They’re great for daily driven trucks, won’t compromise turbo spool-up, provide a hard hitting top end, and are capable of making more than 60 psi of boost. These kits are considered the best in the diesel industry. Click here to see a Randall's Performance customer making 713 hp with this kit.
Each kit is hand fabricated and pre-fitted to ensure proper final fitment. All tubing is TIG welded and all flanges are CNC machined; with O-ring seals where necessary for a leak free seal. All cold side tubing is powder coated (see available color options above).
Note that these kits are year-specific, hence the required "Truck Year" field above. There are kits specifically built for 2011-2012, 2013-2014, and 2015-2016 model year trucks. Knowing the model year of your truck helps us ensure you have a trouble-free installation. In addition, we would also like you to specify which turbo is being used in the valley, be it stock or an aftermarket drop-in.
- *New BorgWarner T6 flange S475 turbocharger (w/cast 75mm compressor wheel)
- *Afe Power dry air filter
- *Fabricated aluminum coolant overflow tank with hoses, fittings, & low coolant sensor
- *Heavy-duty turbo pedestal bracket with built-in oil return line fitting
- *Stainless steel oil feed and drain lines
- *All required tubing: downpipe, hot pipe, cold pipe, intake, IC pipe
- *Battery tray (passenger side battery remains under the hood)
- *New passenger side 3-inch intercooler tube
- *3-inch fabricated Y-bridge for vastly improved airflow into your engine
- *Solid one-piece cold pipe is standard in all kits
- *All required silicone boots, clamps, hardware, and V-bands
- **Passenger side battery remains under the hood
Options Above Explained:
- *Powder coated Compressor cover: This option adds powder coating to the compressor cover of the S400 to match the rest of the kit
- *Powder coated Driver Side Intercooler Pipe: a fully fabricated, 3-inch diameter turbo to engine pipe (vs. the 2½-inch factory pipe’s diameter)
- *S400 Upgrade: Your choice of a billet compressor wheel S475, cast wheel s480, billet S480, or billet S484 with Race Cover
- *Upgraded up-pipes: 2-inch fabricated stainless steel up pipes. Symmetrical pipes, not crushed, (for Twin Turbo applications only)
- *Outerwear Filter Cover: A water repellant air filter cover makes filter cleanings less frequent and easier (the filter pleats do not fill up with debris)
- *Heat blanket for S400 turbo: For the turbine (exhaust) housing, they help control under hood heat and aid spool up
- *PCV Reroute Kit: Keeps engine oil, soot, carbon, and sludge buildup from accumulating in your intake, turbo, intercooler, and heads
- *3-inch Y-Bridge: If you already have a Wehrli 3-inch Y-bridge kit on your truck, you will want to select “No” for this option (as a 3-inch Y-bridge comes standard with this twin turbo kit)
Turbo Exhaust Housing Options Explained:
**All S400 turbochargers come with a 1.32 A/R exhaust housing standard. The standard 1.32 A/R exhaust housing is ideal for trucks utilizing larger injectors and customers seeking maximum horsepower potential. For trucks that are used to tow regularly and have stock or smaller injectors, we recommend the optional 1.10 A/R exhaust housing for quicker turbo response (the smaller housing allows the S400 to be driven harder, which aids spool up and responsiveness at cruising speeds).
POWDER COAT COLOR OPTIONS: