If you own a Subaru BRZ, you’re already familiar with the car’s balanced handling and peppy FA20 engine. But like many enthusiasts, you might be looking for affordable ways to unlock more power without a turbo or supercharger. A cold air intake (CAI) is one of the most cost-effective modifications you can make, and installing it yourself saves even more money. In this comprehensive guide, we’ll walk through everything you need to know to install a cold air intake on your Subaru BRZ, from selecting the right kit to fine-tuning the setup for maximum performance. With a few hand tools and an afternoon’s work, you can enjoy a noticeable boost in throttle response, a throatier intake note, and genuine horsepower gains—all while keeping your wallet happy.

Why a Cold Air Intake Makes Sense for the BRZ

The Subaru BRZ, along with its Toyota 86/Scion FR-S siblings, uses a naturally aspirated 2.0-liter boxer engine (FA20) that breathes through a restrictive factory airbox. The stock intake prioritizes noise reduction and engine bay packaging over airflow. By replacing it with a cold air intake, you allow the engine to draw in denser, oxygen-rich air from outside the engine bay, improving combustion efficiency. Dyno results from popular BRZ forums consistently show gains of 8–12 horsepower and 6–8 lb-ft of torque at the wheels with a well-designed CAI—numbers that are meaningful for this chassis. More importantly, the intake’s larger-diameter tube and high-flow filter reduce intake restrictions, sharpening throttle response and letting the boxer engine rev more freely.

Beyond power, a cold air intake also enhances the driving experience with a more aggressive intake growl, especially above 4,000 RPM. Some kits also include a heat shield that further isolates the filter from hot engine air, maximizing the density of the incoming charge. And because the BRZ’s ECU can adapt to increased airflow within parameters (within limits), many owners report fuel economy improvements under normal driving conditions due to more efficient combustion.

Cold Air Intake vs. Short Ram Intake for the BRZ

Not all intake systems are created equal. Before choosing a kit, it’s important to understand the difference between a true cold air intake and a short ram intake. A cold air intake routes the filter into a low-pressure area, typically inside the front bumper or behind a fender liner, where ambient air is cooler. A short ram intake, on the other hand, places the filter inside the engine bay, where temperatures are higher. On the FA20, the factory intake already pulls air from a high-pressure zone near the grille, so a short ram often delivers less consistent gains because engine bay heat soak can reduce air density. Genuine cold air designs, such as those from Perrin, AEM, and Injen, place the filter in a cool zone, often using a protective box or duct to shield it. For the BRZ, a true CAI is the recommended route to realize the best power gains and avoid losing power on hot days.

Tools and Materials You’ll Need

Gathering everything beforehand makes the installation smooth and avoids frustrating trips to the toolbox. Most cold air intake kits for the BRZ include the intake tube, filter, couplers, clamps, heat shield, and necessary brackets. Here’s the complete list of tools and supplies to have on hand:

  • Socket set (metric, 8mm, 10mm, 12mm, 14mm deep sockets recommended)
  • Ratchet and extensions
  • Flathead screwdriver (for hose clamps and prying trim clips)
  • Phillips screwdriver
  • Torque wrench (inch-pounds for small fasteners)
  • Side cutters or pliers (for zip ties or push pins)
  • Shop towels and degreaser
  • Protective gloves
  • Masking tape or painter’s tape (to mark hoses or sensors)
  • Jack and jack stands or ramps (if you need to reach under the car for filter placement)
  • Subaru BRZ service manual or online guide (torque specs, sensor locations)

Most kits will also come with a small packet of silicone lubricant for the filter coupler—use it sparingly to avoid excess being drawn into the intake.

Step-by-Step Installation Guide

1. Prepare Your Vehicle

Park the BRZ on a level surface and allow the engine to cool completely—the intake system can be hot after a drive, especially the throttle body and intake tube. Disconnect the negative battery terminal with a 10mm wrench and isolate the cable end to prevent accidental reconnection. This step resets the ECU and prevents any electrical shorts when removing sensors. While waiting, remove the engine cover (two 10mm bolts) to improve access to the intake area. Take a photo of the stock layout for reference if needed.

2. Remove the Stock Air Intake System

The factory intake consists of a resonator, intake tube, airbox, filter, MAF (Mass Air Flow) sensor housing, and sometimes a small vacuum hose. Follow these steps carefully:

  • Using a flathead screwdriver, loosen the hose clamp securing the intake tube to the throttle body (located on the passenger side of the engine).
  • Unplug the MAF sensor connector by pressing the tab and pulling straight back. Do not twist or pull on the wires.
  • Loosen the clamp at the airbox (the large plastic box that holds the filter). You might need a 8mm socket for the bolt-style clamp.
  • Remove the airbox by lifting it upward—it may have rubber grommets holding it to the chassis; gently pull these free.
  • Detach any vacuum hoses or crankcase vents attached to the stock intake tube. The BRZ has a small hose from the PCV system; use pliers to slide the spring clamp off.
  • Remove the resonator (a plastic chamber attached to the intake tube on some models) by unclipping it or loosening a screw.
  • Pull the entire intake assembly out of the engine bay. Set aside the factory filter if you plan to keep it as a spare.

Note: Some kits require removal of the rubber intake duct that runs from the grille to the airbox. Use a trim tool or flathead to release the push pins holding this duct in place.

3. Install the New Cold Air Intake

Now for the rewarding part—fitting your aftermarket system. The exact steps vary by kit, but the general process is as follows:

  • Test fit the heat shield: If your kit includes a heat shield (highly recommended), loosely install it in the engine bay first. It typically mounts to the same points as the factory airbox or to the chassis using brackets. Use a 10mm socket to attach the brackets, but don’t tighten fully until the intake tube is in place.
  • Install the filter: Attach the high-flow filter to the end of the intake tube (or to a separate mounting tube that goes to the fender). Use the provided clamp and snug it by hand. Some filters require pre-oiling (cotton-gauze types). If you’re using a dry filter, skip oil. Ensure the filter is oriented so it faces the incoming air from the grille or fender cavity.
  • Route the intake tube: Position the tube so it connects to the throttle body on one end and the filter assembly on the other. Slide the silicone coupler over the throttle body neck first, then tighten the clamp. On the BRZ, the throttle body opening faces downward—use an extension and universal joint on your socket to reach the clamp. Torque to 35-45 inch-pounds (check your kit specifications).
  • Mount the MAF sensor: The MAF sensor must be installed in the same position relative to the airflow as the factory setup—the sensor is directional. Clean the sensor body gently, then insert it into the new MAF housing on the intake tube. Secure with the included screws (typically two small Phillips). Do not overtighten.
  • Connect vacuum hoses: If your kit provides a port for the PCV hose, attach it using a small silicone hose and clamp provided. Double-check that no vacuum lines are kinked or blocked.
  • Finalize heat shield: Tighten the heat shield brackets and snap or screw the shield into place over the filter. Ensure the shield seals against the hood to block hot air from the radiator.

Most BRZ cold air kits place the filter behind the passenger headlight, inside the fender well. To reach this area, you may need to remove the inner fender liner (plastic wheel well cover) and the plastic splash shield under the bumper. Use a socket to remove the push pins; a trim tool helps pop them out without breaking the plastic.

4. Reconnect Sensors and Battery

Plug the MAF sensor connector back in until it clicks. Reconnect any other sensors you unplugged (e.g., IAT sensor on some kits). Double-check all hose clamps and couplers for tightness. Reattach the negative battery terminal and torque to 8 ft-lbs (do not overtighten). Start the engine and let it idle for about 2 minutes to allow the ECU to relearn the idle. It may idle a bit high initially; this is normal as the ECU adapts to the increased airflow.

Pro tip: Before your first drive, verify that no wires or hoses are rubbing against the intake tube or the heat shield. Use zip ties to secure any loose harnesses away from moving parts.

5. Test the Installation

Take the BRZ for a test drive on a quiet road. Listen for any hissing, whistling, or sucking sounds that indicate an air leak. A consistent smooth idle (around 700 RPM in neutral) and immediate throttle response are good signs. Accelerate through the rev range—you should notice a sharper intake sound and a slight seat-of-the-pants power increase above 3,000 RPM. If the check engine light illuminates, stop driving and check that the MAF sensor is plugged in properly and that all vacuum lines are connected. Most CAI installations for the BRZ will not trigger a CEL if done correctly. However, if you’ve installed a kit that moves the MAF sensor far from the throttle body, the ECU may need a professional calibration. Some users report a temporary CEL due to lean conditions on aggressive intakes; in that case, an ECU tune is recommended.

Choosing the Right Cold Air Intake Kit for Your BRZ

Not all CAI kits are equal in design, materials, or sound. Here’s a quick overview of reputable options to help you decide:

  • Perrin Intake System: Known for excellent fitment and quality. Uses a silicone tube with a dry cone filter. Includes a heat shield. Gains of 10-12 hp reported. Perrin Performance
  • AEM Cold Air Intake: A true cold air design with the filter in the front bumper area. Features a washable dry filter (no oil required). Good for consistent power in hot climates. AEM Intakes
  • Injen Technology SP Series: Short ram style, but includes an optional heat shield. Less restrictive than stock, but can suffer heat soak on hot days. Still a good budget choice for sound. Injen Technology
  • Mishimoto Intake System: Fully sealed aluminum housing that mounts in the factory location. Keeps filter away from heat; includes a high-flow cotton filter. Gains around 8 hp. Mishimoto

When selecting a kit, prioritize designs that locate the filter outside the engine bay or inside a fully sealed box. Also check that the intake tube diameter matches the throttle body (stock is about 2.75 inches); too large a diameter can reduce airflow velocity and hurt low-end torque.

Tuning and ECU Considerations

The FA20 engine’s ECU has some learning ability, but it is limited. For a simple cold air intake replacement, the ECU can usually adapt fuel trims to the increased airflow without a tune. However, if you’re sensitive to throttle response or see persistent negative fuel trims (past -10%), consider getting an ECU tune. Companies like OpenFlash and Tuning Technology offer inexpensive off-the-shelf tune files that account for the greater airflow from a CAI. A tune also unlocks additional power from the intake, often 3-5 hp more than the intake alone. If you plan on adding headers or a full exhaust later, a tune becomes essential to avoid knock and poor drivability. For daily driving with just an intake, the stock tune is acceptable for most owners.

Important: The BRZ uses a MAF sensor that is sensitive to turbulence. Some intake tubes that lack a flow straightener can cause erratic readings and a check engine light. If your kit did not include a MAF honeycomb or straightener, it’s wise to purchase a generic one and install it in the tube before the sensor. This ensures stable idle and proper fueling.

Maintenance and Long-Term Care

Unlike a short ram, a cold air intake’s filter is exposed to road debris and moisture (if mounted low behind the bumper). Regular inspection is required:

  • Check filter condition every 5,000 miles: Remove the filter and inspect for dirt, oil residues (if oiled), or water ingress. Clean dry filters with a gentle vacuum from the inside out. Oiled types require special cleaning kits.
  • Keep the heat shield sealed: Over time, the rubber gasket on the heat shield can degrade. Replace it if gaps appear, or use weatherstripping foam to maintain a tight seal against the hood.
  • Monitor intake tube connections: Clamps can loosen due to vibration. Tighten them every 6 months or at each oil change.
  • Beware of hydro locking: Driving through deep puddles with a low-mounted filter can suck water into the engine, causing catastrophic damage. Consider a bypass valve or a fabric water-repellent sock for the filter if you live in a rainy area.

With proper care, a quality cold air intake will last the life of the car and keep delivering consistent power gains.

Final Thoughts

Installing a cold air intake on your Subaru BRZ is one of the most satisfying DIY modifications you can do. The cost is a fraction of what a professional shop would charge, and the installation is achievable by any home mechanic with basic tools. The result is a more responsive engine that sounds thrilling and pulls harder through the midrange. While the gains aren't astronomical, they are noticeable in daily driving and on track days. Combine the intake with a lightweight pulley and a tune, and the BRZ transforms into an even more engaging machine. Always check forums like FT86 Club for specific tips on your intake brand. So grab your socket set, order that intake kit, and enjoy the satisfaction of building your own performance—one bolt at a time.