AEM (21-728C) Cold Air Intake System

Why Upgrade Your Mazdaspeed3 with the AEM 21-728C?

Because the factory intake is choking your turbo harder than your wastegate.

The 21-728C gives you:

• A major jump in airflow versus the OEM airbox

• Quicker turbo spool and response

• More consistent airflow under boost

• A deep, aggressive intake + turbo sound

• AEM’s Dryflow oil-free filter (safe for the sensitive MAF)

• Powder-coated mandrel-bent aluminum intake tube

• A heat-shielded design that helps reduce hot-air ingestion

For a platform that responds extremely well to airflow mods, this intake is a top-tier upgrade.

AEM Cold Air Intake Systems are designed to produce horsepower and torque gains. They replace the restrictive factory air box and air filter to give you better performance and better engine sound.

Key Features of the AEM 21-728C Cold Air Intake

🌀 Mandrel-Bent Aluminum Intake Tube

Engineered diameter for stable fueling and correct MAF readings.

🧼 AEM Dryflow Filter (Oil-Free)

• Washable, reusable

• No oil to foul MAF sensors

• High filtration without airflow restriction

❄ Cold-Air Routing

Designed to draw cooler air from behind the front bumper — crucial for turbo performance.

AEM cold air intakes relocate the air filter outside the engine compartment so cooler air can be fed into your engine. Cooler air carries more oxygen, which translates into a more intense explosion in the combustion chamber for more horsepower and torque.

🔧 Clean OEM-Level Fitment

Mounts using factory locations, includes all brackets/hardware, no splicing or cutting.

🎧 Turbo Sound Upgrade

Hear the spool, hear the surge, hear the “psssht” — without the obnoxious drone.

AEM Cold Air Intakes include an oversized AEM Dryflow synthetic washable air filter for outstanding air flow, filtration, and performance while allowing easy oil-free cleaning.

What Gains Can Mazdaspeed3 Owners Expect?

The 2.3L DISI loves airflow, so expect:

• Faster throttle + turbo response

• Better top-end pull

• Sharper boost transitions

• Noticeably improved sound and character

• Support for future mods like downpipes, exhausts, and tuning

With a tune, this intake becomes a supporting mod for big gains.

They include a mandrel-bent aluminum intake tube and high quality hardware designed to reduce restriction and reduce intake temperature.

Daily-Driver Friendly

• Works with stock ECU (though tuning is recommended for maximum benefit)

• Nothing about this system compromises MPG or reliability

• Dryflow filter = easy maintenance

• Designed for long-term durability, even for spirited driving

This is the “wake up the turbo without making your car annoying” upgrade.

The design and components of each intake system vary so consult the installation instructions for more information on the contents of each part number. This Air Intake cannot be sold in California. It is not legal for use in California or other states adopting California emission standards.