About this product
The factory intake on a 2020-2026 Chevrolet Silverado / GMC Sierra 2500HD/3500HD 6.6L Duramax L5P is restrictive plastic from the fender to the turbo. The Wehrli Stage 2 4" Intake Kit with Air Box (Manufacturer Part # WCF100684) replaces the whole path — 4" fabricated aluminum pipe, a 4" intake horn with PCV port and surge ring, and a sealed 10 gauge air box that seals to the functional ram air port in the hood. Bolt on, no tuning. One setting must be changed before you start the truck — see Notes.
Why Choose the Wehrli Stage 2 4" Intake Kit?
- Includes the intake horn – this is what separates Stage 2 from the standard kit. The horn is over an inch larger than OEM and removes the restriction sitting right at the turbo inlet.
- Seals to the hood ram air duct – the kit ships with the seal for the functional ram air port, so the box draws cold air from the hood duct and the inner fender instead of underhood heat.
- 4" aluminum piping – large diameter with smooth aerodynamic bends, improving intake air velocity and volume.
- 10 gauge aluminum box and lid – the lid element lifts off for a filter check without pulling the box apart.
- Dry filter with an Outerwears cover – hydrophobic pre-filter keeping water and grit off the element.
- More sound – a noticeably more aggressive engine and turbo note under acceleration.
- Custom powder coat – the whole assembly in your choice of Wehrli's colors. Made in the USA.
Kit Includes
- 4" intake pipe, fabricated aluminum
- 4" intake horn with PCV port and surge ring
- Air box and lid, 10 gauge aluminum sheet
- Dry air filter
- Outerwears pre-filter cover
- Seal for connection to the functional ram air port on the hood
- High quality silicone boot and stainless steel T-bolt clamps
- Installation hardware
Installation Highlights
Installs easily with basic hand tools and needs no tuning — it fits a stock truck with no other modifications or upgrades necessary. Disable the air filter monitoring system before the first start.
Fits These Models
2020, 2021, 2022, 2023, 2024, 2025 and 2026 Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD with the 6.6L Duramax L5P.
Specifications
- Intake pipe: 4" diameter fabricated aluminum
- Intake horn: 4" with PCV port and surge ring, over an inch larger than OEM diameter
- Air box and lid: 10 gauge aluminum sheet
- Filter: dry element with Outerwears hydrophobic pre-filter cover
- Replaces GM part numbers: 84841229, 84841225, 84262962, 85614333, 84554702
- Shipping weight: 21.0 lbs
- Package dimensions: 20" W x 18" H x 20" L, ships in its own box
- Finish: custom powder coat, color selected above
- Made in the USA
Key Features at a Glance
- Intake horn included - the Stage 2 difference, an inch larger than OEM.
- Hood ram air seal included - real cold air, not underhood air.
- 4" fabricated aluminum - replaces the restrictive plastic tract.
- 10 ga. sealed air box - serviceable lid.
- No tuning required - bolt on to a stock truck.
- Custom powder coat finish - pick your color above.
Notes
- ⚠ Disable the air filter monitoring system before initial start up. Wehrli is explicit: skip it and the truck throws a SERVICE AIR FILTER message that requires a dealership to reset. When the setting is correct, air filter life reads as disabled.
- Lead time varies by color. WCFab Red, WCFab Grey, Candy Teal, Gloss White and Gloss Black are stocked and ship in 3-5 business days. All other colors are made to order on a 10-15 business day lead time.
- Wehrli also offers this truck's charge piping separately — call if you want the full Stage 2 bundle with intercooler pipes.
FASS SKU: WCFWCF100684
Manufacturer Part #: WCF100684
Questions? We’re Here to Help.
Have questions about upgrades for your 6.6L Duramax L5P? Contact FASS Motorsports and we’ll get you dialed:
Phone: 636-429-7020
Email: info@fassmotorsports.com
Description supplied by FASS Motorsports through its current Shopify listing. Product, performance, and health claims are the seller’s and have not been independently verified by StorkScout.
