How does the Stage 3 kit differ from Stage 2?

Stage 3 adds the 3.5-inch ceramic coated down pipe to the full Stage 2 package. Stage 2 covers the intake system and intercooler pipes, while Stage 3 extends those airflow improvements to the exhaust side of the turbo.

Will the Illusion Blueberry finish hold up to engine bay heat?

The powder coat is applied to the intake and intercooler components. The down pipe uses a separate black ceramic coating with pre-installed heat wrap specifically designed for exhaust temperatures.

Does this kit require removal of any emissions equipment?

The down pipe connects to the DOC outlet flange and retains all OEM sensor bungs. Note that this kit is not CARB approved and cannot be shipped to California.

Is any sealant or gasket maker needed during installation?

No. All connections use silicone boots with stainless T-bolt clamps or CNC machined flanges with double O-ring seals. Refer to Wehrli's installation instructions for the specific procedure.

Wehrli 20-25 Chevrolet 6.6L Duramax L5P Stage 3 High Flow Intake Bundle Kit - Illusion Blueberry

Specifications

Brand: Wehrli
Part #: WCF100418-IBB
UPC: WCF100418-IBB

Wehrli 20-25 Chevrolet 6.6L Duramax L5P Stage 3 High Flow Intake Bundle Kit - Illusion Blueberry

Name: Wehrli 20-25 Chevrolet 6.6L Duramax L5P Stage 3 High Flow Intake Bundle Kit - Illusion Blueberry
Brand: Wehrli
Price: 2062.34 USD
Availability: InStock

$2062.34

On Backorder

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

Fits 2020-2025 Chevy/GMC 6.6L Duramax L5P. Stage 3 bundle with intake, intercooler pipes, and 3.5-inch down pipe in Illusion Blueberry.

Key Features

Fits 2020-2025 Chevrolet Silverado and GMC Sierra 2500 HD/3500 HD with 6.6L L5P Duramax
Complete Stage 3 package: intake, intercooler pipes, and down pipe in one bundle
4-inch intake pipe with enclosed air box, dry filter, and Outerwears hydrophobic pre-filter cover
Intake horn is over an inch larger than stock with PCV port and surge ring
3-inch driver-side intercooler pipe eliminates factory resonator and middle boot joint
3.5-inch passenger-side intercooler pipe with CNC flange and double O-ring seal

⚠️ 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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Will this fit your vehicle?

Moderate difficulty to install

Bolt-on installation covering intake, intercooler pipes, and down pipe with hand tools -- no cutting, welding, or tuning.

Product Details

Inside this Wehrli Custom Fab Stage 3 kit you get a complete intake-to-exhaust airflow package for the 2020-2025 Duramax L5P: a 4-inch intake pipe with enclosed air box and dry filter, an oversized intake horn with PCV port and surge ring, a 3-inch driver-side intercooler pipe, a 3.5-inch passenger-side intercooler pipe, and a 3.5-inch ceramic coated down pipe -- all finished in Illusion Blueberry powder coat and built to bolt onto Chevrolet Silverado and GMC Sierra 2500 HD and 3500 HD trucks.

The intake draws cold air through the hood ram air duct and inner fender using 14-gauge aluminum tubing with smooth mandrel bends. The intake horn is over an inch larger than stock, and the Y-bridge connection replaces the factory clip ring with a silicone boot and stainless T-bolt clamp for a more reliable seal under boost. The Outerwears hydrophobic pre-filter cover protects the dry filter element and keeps contaminants out of the MAF sensor and turbo.

Downstream, the intercooler plumbing gets a thorough upgrade. The driver-side hot pipe is a one-piece 3-inch tube that eliminates the factory resonator and middle boot joint. The passenger-side cold pipe uses a CNC machined flange with double O-ring seal, replacing the factory's plastic and rubber assembly that tends to blow apart under boost. Both are 14-gauge aluminum with mandrel bends.

The 3.5-inch down pipe handles the exhaust side, replacing the crushed factory piece with a ceramic coated and heat-wrapped unit for better thermal management. It connects to the DOC outlet flange and mates with the OEM exhaust system via the factory 4-bolt connection. Every sensor bung is accounted for, and the entire kit installs with hand tools -- no tuning, cutting, or welding needed.