AEM 21-784C Cold Air Intake System

Why Upgrade with the 21-784C?

Because your ILX deserves to breathe like it means it. This upgrade offers:

• Improved airflow with a mandrel-bent aluminum intake tube that replaces the restrictive OEM system.

• Better throttle response — the engine reacts faster since it’s getting less restriction.

• More engaging induction sound — you’ll hear the air moving in, subtle but noticeable.

• AEM Dryflow oil-free washable filter — less mess and built for longevity (up to 100,000 miles before cleaning under ideal conditions).

• Gunmetal gray finish on the tube for stylish under-hood appearance.

• Est. gains: Up to about +15 HP @ ~5,900 RPM (per AEM spec) for this kit.

The AEM 21-784C Performance Cold Air Intake System produces horsepower and torque gains by replacing your vehicle’s restrictive factory air filter and air intake housing. This air intake system was designed, tuned and dyno-tested to fit specific Acura ILX models.

Key Features

• Oversized Dryflow synthetic washable air filter (oil-free media).

• Mandrel-bent aluminum intake tube, powder-coated gunmetal.

• Built to work with factory mass-air sensor (MAF) and PCV hose/emissions hardware.

• Backed by AEM’s lifetime limited warranty

Air enters the system through an oversized AEM Dry flow synthetic washable air filter for outstanding air flow, filtration and performance. The air filter is located in the original air box location and is protected by a heat shield which is designed to reduce intake air temperature and increase horsepower.

Performance Expectations

On the ILX 2.4L you can expect:

• Faster throttle tip-in and more immediate response from light pedal input.

• Smoother airflow at higher RPMs, and better engine feel overall.

• A modest horsepower bump (~+15 HP claimed) which for a naturally aspirated engine is meaningful.

• Improved engine tone — you’ll hear the difference, especially under load.

The air intake tube is constructed from mandrel-bent aluminum featuring a durable gunmetal gray powder coated finish. This air intake system was developed to accommodate the engine’s factory emissions control devices including the mass air flow sensor and PCV hose.

Daily-Driver Friendly

• Designed to work with the stock ECU with no tune required for baseline improvement.

• Filter maintenance is minimal thanks to the oil-free design.

• No trade-offs in drivability — the ILX remains refined and comfortable.

• However: Some listings show this part in a Non-CARB compliant version (for certain states) so be sure to verify local legal status if you’re in California or a CARB-regulated region

The tapered cylinder shaped AEM Dry flow air filter is made from an oil-free, synthetic filter media that can be used for up to 100,000 miles before cleaning is needed (depending on driving conditions).

Installation Snapshot

Estimated install time: 45-90 minutes.

1. Remove the factory airbox and intake piping.

2. Install the AEM heat-shield/intake assembly per instructions.

3. Mount the new intake tube, attach the Dryflow filter.

4. Ensure clamps, sensors, and couplers are tight and properly seated.

5. Start the engine, listen for the induction tone, and monitor for any errors.

The air intake system is easy to install with commonly available tools and it is backed by AEM’s Lifetime Limited Warranty. Some AEM air intakes are not legal for sale or use in California and other states adopting California emission standards, while others are 50 state legal. View the 21-784C vehicle applications to determine the legal status for each vehicle.