Universal Cold Air Intake System — 4-Inch Diameter

Fitment

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Description

AEM 21-5011 supplies 4-inch aluminum tubing, couplers and a Dryflow filter for fabricating an intake around an engine swap or custom engine bay.

Technical specifications

Tube diameter 4 in Tube bends 45°, 90° and 120° Straight tube length 36 in Tube finish Raw aluminum Filter Oil-free Dryflow 21-2059DK Couplers Seven Application and compatibility

A fabrication kit for engine swaps and custom engine bays, requiring a designed intake route, suitable throttle/MAF connections and final fuel-trim checks.

Manufacturer documents

Manufacturer product information

21-5011 installation instructions

Key features

• Three bent sections plus a 36-inch straight section support custom routing
• Oil-free 21-2059DK filter
• Weld-on Hitachi blade-style MAF pad and couplers for a tubular MAF arrangement

Specifications

General

What's in the box

• Four aluminum tubes: 45°, 90°, 120° and 36-inch straight
• 21-2059DK air filter
• One 90° elbow coupler
• Four 4-inch straight couplers
• Two 4-to-3.75-inch adapters
• Two blank 12-inch brackets
• Hitachi MAF adapter pad
• Two rubber mounts
• 35-inch breather hose and aluminum nipple
• Six large clamps and two small hose clamps
• Four washers and four M8 nuts

Vehicle MAF sensor, additional application-specific adapters and fabrication/welding work are separate.

Install & Results

At a glance

• Cut and trial-fit the tubing before final welding. Follow the manual’s filter clearance and straight-joint requirements. Position the MAF as directed and verify fuel trims before finalizing its mounting. Use the rubber isolation mounts and check clearance through engine movement.

Emissions

Status: Manufacturer usage restriction

The manufacturer instructions limit California use to racing vehicles that may never be used on a highway.