Will this fit my 2015.5 or 2016 Duramax?

No. This kit is for 2011-2015 LML models with the V-band exhaust connection at the turbo downpipe. If your truck uses a 3-bolt exhaust connection (common on late 2015 and 2016 models), you need a different configuration -- see Wehrli models WCF100439 or WCF100705.

How much total airflow improvement does this Stage 3 kit achieve?

Wehrli measures gains at each component: 37% at the intake pipe, 5.6% at the intake horn, 33% through the Y-bridge (with 40% at the upper manifold), 23% on the cold side pipe, and 18% on the hot side pipe. The downpipe further reduces exhaust restriction.

Does the CNC Y-bridge on the LML kit differ from the LMM version?

Yes. The LML Y-bridge is a precision CNC machined cast aluminum piece, while the LMM version is a fabricated two-piece design. Both achieve significant flow gains, but the LML bridge uses a different mounting and connection layout specific to the 2011-2015 engine.

Is this kit emissions compliant?

The kit retains the factory intake air heater, throttle valve, and EGR connections. It is not CARB certified, so check your local and state regulations regarding aftermarket intake modifications before purchasing.

Specifications

Brand: Wehrli
Part #: WCF100505-GB
UPC: WCF100505-GB

Wehrli 11-15 Duramax LML Stage 3 High Flow Bundle Kit - Gloss Black

Name: Wehrli 11-15 Duramax LML Stage 3 High Flow Bundle Kit - Gloss Black
Brand: Wehrli
SKU: wehrli-wehrli-11-15-duramax-lml-stage-3-high-flow-bundle-kit-gloss-black-t14-930880
Price: 2823.36 USD
Availability: BackOrder

$2823.36

On Backorder

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

Fits 2011-2015 Chevy Silverado 2500HD & 3500HD with 6.6L LML Duramax. Stage 3 high flow bundle in Gloss Black with CNC Y-bridge, intake, intercooler pipes, and V-band downpipe.

Key Features

Fits 2011-2015 Chevrolet Silverado 2500HD and 3500HD with the 6.6L LML Duramax diesel engine.
Precision CNC machined cast aluminum Y-bridge with 33% total airflow gain over the factory bridge.
High flow upper intake manifold moves 40% more air than stock; 3 in. upper crossover pipe is 20% larger than factory.
4 in. intake pipe with 10 ga. aluminum air box and dry filter achieves 37% airflow improvement over stock.
4.8 in. intake horn with 5.6% airflow gain; eliminates factory resonator for improved turbo sound.
3.5 in. cold side intercooler pipe (23% gain) and 3 in. hot side intercooler pipe (18% gain) over stock.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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Moderate difficulty to install

Bolt-on installation with standard hand tools; the number of components (intake, intercooler pipes, Y-bridge, downpipe) means a full afternoon of work.

About this part

Product Details

Built for the 2011-2015 LML Duramax, this Wehrli Stage 3 High Flow Bundle Kit in Gloss Black replaces every major airflow restriction from the filter to the downpipe. Where the factory design relied on plastic parts and restrictive sizing, Wehrli substitutes heavy-gauge aluminum and stainless steel with measured flow gains at every stage.

Precision CNC Y-Bridge

At the core of this kit sits Wehrli's cast aluminum Y-bridge, precision CNC machined for a 33% total airflow gain over stock. Unlike the restrictive OEM bridge that bottlenecks the entire intake tract, this piece opens things up with a 20% larger 3 in. fabricated aluminum upper crossover pipe and a high flow upper intake manifold that moves 40% more air than the factory part. The result is noticeably improved throttle response and turbo spool. Factory intake air heater, throttle valve, and EGR connections are all retained.

Intake and Intercooler Piping

A 4 in. aluminum intake pipe with 10 ga. aluminum air box and dry filter assembly (plus Outerwears pre-filter cover) replaces the restrictive plastic factory setup for a 37% airflow improvement. The 4.8 in. intake horn adds another 5.6% over stock and eliminates the factory resonator for a more aggressive turbo sound. On the intercooler side, the 3.5 in. cold side pipe gains 23% and the 3 in. hot side pipe gains 18% over their factory counterparts. Reinforced silicone boots and stainless T-bolt clamps handle the increased pressures.

V-Band Stainless Downpipe

A 3 in. stainless steel downpipe with V-band flange and heat wrap completes the package, reducing exhaust back-pressure right after the turbo. Compatible with 2011-2015 LML models using the V-band exhaust connection. No tuning required -- bolts right on. Finished in Gloss Black powder coat.