Image coming soonWehrli 2020-2026 L5P Duramax Stage 2 High Flow Intake Bundle Kit
Can I pick up my order or have it installed at your shop?
Can I pick up my order or have it installed at your shop?
Absolutely. We offer local pickup on most products and full professional installation at our shop in Washington, MO. Whether you just want to grab your parts or have our techs handle the install, we’ve got you covered. Give us a quick call at 636-429-7020 or message us to schedule a visit — we’ll make sure the parts are ready when you arrive.
How do I know if this part fits my vehicle?
How do I know if this part fits my vehicle?
Unsure if it’ll fit? No problem — that’s what we’re here for. Send us your vehicle’s year, make, and model, and we’ll verify fitment before you order. We can also point you toward compatible upgrades or supporting parts if needed.
What if I need to return a product or it’s defective?
What if I need to return a product or it’s defective?
Most unused items can be returned within 30 days in their original packaging. Some products are covered by a manufacturer’s warranty as well. If something arrives damaged or doesn’t meet your expectations, just let us know — we’ll help you get it replaced, refunded, or repaired. (Tracking updates are also emailed automatically once your order ships.)
What's the lead time on custom or fabricated parts?
What's the lead time on custom or fabricated parts?
Many of our parts are built to order — especially fabricated or performance components. These can take additional time to produce before shipping. Lead times vary by manufacturer and demand, but we’ll always keep you updated along the way. If you’re working on a tight schedule, reach out before ordering at 636-429-7020 and we’ll confirm current availability or estimated ship dates.
Everything from the fender to the Y-bridge, in one box. The Wehrli Stage 2 High Flow Intake Bundle Kit (Manufacturer Part # WCF100414) for the 2020-2026 Chevrolet Silverado / GMC Sierra 2500HD/3500HD 6.6L Duramax L5P combines their Stage 1 charge pipe bundle with the Stage 2 intake kit — 4" fabricated intake, horn, sealed air box, and both intercooler pipes. No tuning required, but there is one setting you must change before you start the truck. Read the Notes.
Why Choose the Wehrli Stage 2 High Flow Intake Bundle Kit?
- Intake and charge piping together – the plastic inlet parts and both restrictive charge pipes handled in one order instead of three.
- 4" intake with a bigger horn – 14 gauge aluminum with smooth aerodynamic bends, and an intake horn over an inch larger in diameter than the OEM piece.
- Cold air from the hood duct and fender – the 10 gauge aluminum air box draws through the factory ram air duct, which drops intake temperatures rather than just relocating the filter.
- 3" one-piece hot side – deletes the OEM middle boot joint, one less place to leak.
- 3.5" cold side with a machined flange – CNC machined with a double O-ring seal and an upgraded silicone boot, replacing the two-piece plastic and rubber factory pipe that splits.
- Serviceable filter – removable air box lid element and a hydrophobic Outerwears pre-filter cover protecting the MAF sensor and turbo.
- Custom powder coat – the whole assembly in your choice of Wehrli's colors. Made in the USA.
Kit Includes
- 4" aluminum intake pipe, 14 gauge
- 4" intake horn with PCV port and Surge Ring
- Air box enclosure, 10 gauge aluminum, with dry filter assembly and Outerwears pre-filter cover
- 3" driver (hot) side intercooler pipe, one piece
- 3.5" passenger (cold) side intercooler pipe with CNC machined double O-ring flange
- Installation hardware, 4" silicone hump boot and stainless steel T-bolt clamps
- Reinforced silicone boots, O-rings and clamps
Installation Highlights
Bolt-on with basic hand tools, no tuning required. Factory connection points and sensors are retained. Disable the air filter monitoring system before the first start — the procedure is at the end of Wehrli's install guide, linked below.
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, 14 ga. aluminum
- Intake horn: 4" with PCV port and Surge Ring, over an inch larger than OEM diameter
- Air box: 10 ga. aluminum sheet, removable lid element
- Driver (hot) side pipe: 3" diameter, one piece, OEM middle boot joint deleted
- Passenger (cold) side pipe: 3.5" diameter with CNC machined double O-ring flange
- Package dimensions: 36" W x 24" H x 12" L, ships in its own box
- Finish: custom powder coat, color selected above
- Made in the USA
Key Features at a Glance
- Stage 1 bundle plus Stage 2 intake - the full inlet and charge path in one kit.
- 4" intake, 3" hot side, 3.5" cold side - every factory restriction upsized.
- 10 ga. sealed air box - fed by the factory ram air duct.
- CNC machined double O-ring flange - seals where the plastic pipe fails.
- 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 and idle. Wehrli is explicit about this: skip it and the truck throws a SERVICE AIR FILTER message that requires a dealership visit to reset. When the setting is right, air filter life reads as disabled. The steps are at the end of the install guide.
- Lead time varies by color. WCFab Red, WCFab Grey, Gloss Black, Gloss White, Candy Teal and Illusion Purple are stocked and ship in 3-5 business days. All other colors are made to order on a 10-15 business day lead time.
- Stage 3 for this truck adds the 3.5" down pipe on top of this kit.
Installation Instructions Available Here
FASS SKU: [ADD FASS SKU]
Manufacturer Part #: WCF100414
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
This part fits the following vehicles:
| Years | Make & Model |
|---|---|
| 2020 | Chevrolet Silverado 2500 HD |
| 2020 | Chevrolet Silverado 3500 HD |
| 2020 | GMC Sierra 2500 HD |
| 2020 | GMC Sierra 3500 HD |
| 2026 | Chevrolet Silverado 2500 |
| 2026 | Chevrolet Silverado 3500 |
| 2026 | GMC Sierra 2500 |
| 2026 | GMC Sierra 3500 |
Fitment is listed by year, make and model. Some applications also depend on cab, bed, drivetrain or engine — if you are not sure, call 636-429-7020 or send us your vehicle details and we will confirm before you order.
