LML Duramax Twin Turbo 4" Down Pipe

Building a twin or compound turbo LML Duramax means leaving the crushed factory down-pipe world behind. Wehrli’s 4" twin-turbo down pipe is cut for custom racing fabrications that need a larger exhaust path off a BorgWarner S400 T6-style housing — ceramic coated, heat-wrapped, and shipped with the 5" V-band clamp for the turbo connection.

This part (WCF100280): 4" twin-turbo down pipe for LML Duramax custom builds. Pair with WCFab Twin Turbo Pedestal WCF100676 when fitting a BorgWarner S400 T6 turbocharger for proper geometry. Includes high-temp ceramic coating, heat wrap with hose clamps, and the 5" V-band clamp for the S400 T6 exhaust housing.

Fitment gates:

• Not a bolt-in factory turbo / stock-style 3" down pipe — those are separate SKUs (e.g. WCF100121 / WCF100704 / WCF100705)
• Requires a custom twin/compound turbo kit plan and supporting exhaust fabrication
• Confirm pedestal height, turbo housing, and exhaust mating before ordering
• Idaho Falls fabrication/install help available when bay time allows

Shipping: This product cannot ship to California (same restriction as WCFab). Oversized — ships in its own box; confirm freight vs ground at checkout. Free ground over $150 excludes HI/AK.

Call 208-542-7793 with year, turbo plan (S400 T6?), and whether you already have pedestal WCF100676.

Emissions-compliant performance only — Powertech Diesel does not sell deletes or defeat devices. Custom twin-turbo builds must retain required emissions equipment where legally required.