2017-2019 L5P Duramax Stage 2 High Flow Intake Bundle Kit

Stage 2: more air, fewer weak points

Wehrli's Stage 2 kit for the 2017-2019 L5P packages its Stage 1 high-flow bundle plus its Stage 2 intake together, aimed at the weak points in the factory air path that can lead to boost leaks and lost power.

On the intake side, a 4 in. fabricated aluminum pipe, an inlet horn more than an inch larger than stock, and a 10 ga aluminum air box replace the plastic factory parts, drawing cooler air in through the ram-air duct in the hood and the inner fender. Wehrli measured a 25 hp gain from the 4 in. inlet with a max-effort tune.

After the turbo, the two-piece resonator-equipped 2.5 in. hot side pipe and the plastic-and-rubber cold side pipe are replaced by one-piece 3 in. and 3.5 in. 14 ga aluminum pipes. The cold side uses a CNC-machined flange with double O-rings and a silicone boot in place of the factory clip ring.

Who it's for

2017-2019 L5P owners who want a bolt-on airflow upgrade that also fixes the factory leak points.

Key specs (per Wehrli)

What's included

• Aluminum intake tube, 4 in.
• Inlet horn, 4 in., with surge ring and PCV fitting
• Air box, dry filter and pre-filter
• Intercooler pipes: 3 in. hot side, 3.5 in. cold side
• Machined cold side flange with twin O-rings
• Boots (silicone), clamps (stainless T-bolt) and hardware; powder-coated finish

Fitment notes

• Fits 2017-2019 Chevrolet Silverado / GMC Sierra 2500 HD and 3500 HD with the 6.6L L5P Duramax.
• Wehrli says the kit pairs best with compliant tuning and an upgraded drop-in turbo.
• California: Wehrli does not ship this part to California.

Professional install available at Powertech Diesel, Idaho Falls — call 208-542-7793.