AEM-21-819 Cold Air Intake System – Red

✔ Vehicle Fitment — What the AEM 21-819 Fits

Designed specifically for the turbocharged 2.0L WRX:

Subaru WRX – 2.0L FA20DIT Turbo

• 2015 Subaru WRX

• 2016 Subaru WRX

• 2017 Subaru WRX

• 2018 Subaru WRX

• 2019 Subaru WRX

• 2020 Subaru WRX

Fits manual transmission models and CVT (yes, the “I swear it’s not a CVT” crowd too).

Does NOT fit STI models (EJ engine) or 2021+ redesign.

The AEM 21-819 Performance Cold Air Intake System replaces both the left and right side housings. This air intake was designed to fit some Infinity Q50 and Q60 models.

Why Upgrade Your WRX with the AEM 21-819 (Red)?

Because the FA20DIT wants to breathe like a turbo car, not like a clogged Dyson.

The 21-819 gives you:

• Increased airflow compared to the factory intake

• Quicker turbo spool & reduced lag

• More midrange punch

• Deeper, aggressive induction sound

• AEM Dryflow filter – oil-free, washable, MAF-safe

• Red powder-coated aluminum intake tube for maximum style points

• Cooler intake temps thanks to optimized routing & heat shielding

If you like hearing turbo spool, bypass valve sound, and general “Subaru chaos,” this is your happy place.

Both banks uses an oval shaped AEM Dry flow Air Filter. The filter media is made from a synthetic fiber that does not require oiling.

Key Features of the AEM 21-819 Cold Air Intake

🔴 Red Powder-Coated Mandrel-Bent Intake Tube

Smooth internal surface + a bold red finish that looks perfect in the WRX engine bay.

🧼 AEM Dryflow Filter

• No oil

• Washable & reusable

• High filtration

• Zero MAF contamination drama

❄ Cold-Air Placement

Designed to pull cold air from the fender area for lower intake temps under boost.

🔧 Direct Bolt-On Fitment

Retains factory mounting points, includes all hardware, no cutting or drilling needed.

🎧 Turbo Noise Enhancement

The difference in spool + induction volume is chef’s kiss.

The filter also provides excellent filtration and has great air flow. Maintenance is easy since the filter can be used up to 100, 000 miles before cleaning is needed (depending on driving conditions). Individual heatshields keep out engine bay heat .

What Gains Can WRX Owners Expect?

Owners typically report:

• Faster throttle response

• Better boost ramp and earlier turbo engagement

• More stable airflow at high RPM

• Noticeable improvement in induction sound

• Slight horsepower gains (bigger gains possible with tuning)

Pair it with an AccessPort tune and the difference is night-and-day.

The factory MAF sensor mounts directly on the supplied intake tube.

Daily-Driver Friendly

• Works with the factory ECU

• Tune recommended but not required

• No oil = no MAF sensor headaches

• No drone or annoying cabin noise

• Improves sound without making your WRX obnoxious

Your WRX stays perfectly streetable—just much more fun.

The air intake system it is backed by AEM’s Lifetime Limited .

Installation Overview

Estimated time: 45–90 minutes

1. Remove OEM airbox & ducting

2. Install AEM heat shield

3. Mount the red mandrel-bent intake tube

4. Attach the AEM Dryflow filter

5. Transfer MAF sensor

6. Tighten clamps & hardware

7. Enjoy turbo noises all day

Minimal drama. Maximum payoff.

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 21-819 vehicle applications to determine the legal status for each vehicle.