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Wehrli Custom Fabrication S400/S300 Twisted Twin Kit '01-16 Duramax

-Custom 2" Stainless 11g Up Pipes
-5" Intake
-Dry Air filter
-Outerwears Pre-Filter Cover
-SS Oil Feed and Drain Lines with Fittings for both Charger
-Custom T4 Pedestal & Hardware
-Heavy Duty Atmoshpere Turbo Pedestal
-4" Turbo Down Pipe
-3 1/2"
Please Call for Availability


The S300/S400 Twisted Compound Turbo Kit for 2001-2016 Duramax's is designed a little differently than your typical s300/s400 kit. With quick spooling in mind we mount the S300 turbo 90* sideways from its typical position which allows us to build the hot side exhaust pipe between chargers more than half the length of a conventional hot pipe. The s300 Turbine housing is also rotated 90* from the standard position mounted to a custom pedestal. Doing so requires a set of custom 2" Stainless 11g up pipes (Included) which eliminates a full 90* bend in each up pipe (decreasing from the typical 3- 90* bends found in the standard S300/S400 Kits to 2- 90* bends) These two redesigns from a conventional setup result in quicker spooling and decreased EGT levels due to less exhaust restriction.
Properly spec'd setups can operate very well at lower horsepower ratings and still tow extreme weights. But you also have the option to push the horsepower level to over 1000 RWHP. (with proper supporting modifications) Kits are available without turbo chargers but we will need to know what you are planning to use, and in some cases, may need your turbos sent in for the build process. Below we have spec'd out a few popular choice option kits;
1. Daily Driver, Heavy Towing Combination- S364.5 SXE with .83 Turbine Housing paired with a S475 Engineered Turbo Billet Wheel Low Pressure turbo and 1.15 Turbine Housing. This setup works best in the 400HP-700HP Daily Driver, Heavy Towing Combination. This combo is capable of towing loads in the 15-18,000 Range and can still be turned up to lay down 700HP. With the addition of an internally waste gated .83 Turbine Housing for the S300 Turbo, the kit can be pushed to the 750HP range.
2. Daily Driver, Mild Towing Combination- S366 SXE with .90 Turbine Housing paired with a S480 FMW (or Engineered Turbo) Low Pressure turbo and 1.32 Turbine Housing. This combo will operate well in the 500-850HP Range and is still capable of towing upwards of 15,000lbs with correct driving techniques. Adding the .83 internally waste gated housing is a good choice if you do plan to tow heavy but also want to push the 800HP Range.
3. Daily Driver, Racer, Light Towing Combination- S369 SXE with .90 turbine housing paired with a S484 Engineered Diesel Billet Wheel Low Pressure turbo and 1.32 turbine housing. Are you a weekend warrior drag racer that still have a boat to tow? This is the setup for you. With supporting modifications, this combination will break 1000 RWHP but is still very well capable of towing 12,000 lbs. Highly modified engine lower end would be necessary as well as serious fuel upgrades to make 1000 HP, but this setup is a great, street able, daily driver that can impress when needed.