Upgrading the intake system on a 2013–2021 Subaru BRZ (or Toyota GT86 / Scion FR-S) is one of the most effective ways to unlock additional power and a more exciting engine note. The Perrin Cold Air Intake stands out as a proven, well‑engineered option that balances performance gains with ease of installation. Unlike some systems that only alter sound without meaningful airflow improvements, the Perrin intake is designed to reduce restriction and draw cooler, denser air into the FA20 engine. The result is a sharper throttle response, a subtle increase in horsepower, and a throatier intake roar that makes every drive more engaging. In this guide, we break down the benefits, walk through the installation process step by step, and offer maintenance advice to keep your intake performing at its best.

Benefits of the Perrin Cold Air Intake

The FA20 engine in the Subaru BRZ responds well to improved airflow. The factory air box is competent but prioritizes noise dampening and cost savings over performance. The Perrin cold air intake addresses these compromises with several key advantages:

  • Measurable horsepower and torque gains – Independent dyno tests on the FA20 show gains of 8–12 whp and 6–8 lb‑ft of torque at the wheels, with the largest improvements in the mid‑range where the engine feels most responsive during daily driving.
  • Better throttle response – By reducing intake restriction, the engine can draw air more freely. This translates to a more immediate pedal response, especially when accelerating from low RPMs.
  • Aggressive intake sound – The Perrin intake amplifies the natural induction noise of the FA20, producing a deep, growling suction that becomes more pronounced above 3,500 RPM. The sound is distinct but not overwhelming inside the cabin.
  • Lightweight construction – The kit uses a lightweight aluminum tube and a high‑flow dry or oiled filter, saving about 2–3 pounds compared to the stock assembly.
  • Heat shielding – Perrin includes a heat shield that isolates the filter from underhood heat, ensuring that the intake air temperature stays close to ambient. This is critical for maintaining power gains on warm days or during spirited driving.
  • OEM‑style fitment – All mounting brackets, silicone couplers, and hardware are designed to bolt directly into the factory locations without cutting or modifications. The intake reuses the factory MAF sensor and PCV/CCV lines.

Before You Begin: Tools and Preparation

A successful installation starts with proper preparation. The Perrin cold air intake is designed for a straightforward DIY installation, but having the right tools and a clean workspace will prevent frustration. Here is what you will need:

  • Socket wrench set with 8 mm, 10 mm, and 12 mm sockets
  • Flathead screwdriver (for loosening hose clamps)
  • Phillips screwdriver (for removing the factory air box screws)
  • Torque wrench (for tightening bolts to spec: 8–10 Nm for small brackets, 20 Nm for MAF sensor screws)
  • Trim removal tool or plastic pry bar (to release the MAF sensor harness connector without damage)
  • Rubber gloves and safety glasses
  • Shop towels and a vacuum (to clean the area around the air box)
  • Penetrating oil (optional, for stubborn bolts)

Work in a well‑ventilated area, preferably a garage or driveway with the car on a level surface. Allow the engine to cool completely—ideally overnight—to avoid burns from hot components. Disconnect the negative battery terminal to reset the ECU and prevent any electrical shorts. This step also ensures that the engine’s air/fuel learning tables are cleared, so the ECU can adapt to the new intake flow more quickly.

Step‑by‑Step Installation

Follow these instructions carefully. The process typically takes 45 minutes to 1.5 hours for a first‑time installer. Refer to the included Perrin instruction manual alongside this guide for torque values and specific fastener locations.

Step 1: Remove the Factory Air Intake System

Begin by removing the cosmetic engine cover (if equipped) by pulling it upward from its rubber mounts. Using a Phillips screwdriver, loosen the clamp that secures the intake tube to the throttle body. Next, unbolt the factory air box housing using an 8 mm or 10 mm socket. There are three bolts: one near the front bumper, one on the side near the fuse box, and one at the rear near the strut tower. Lift the air box top and carefully set it aside. Disconnect the MAF sensor harness by pressing the release tab and pulling straight out. The sensor itself stays in the stock tube—you will transfer it later.

Detach the rubber intake snorkel that connects the air box to the front grille area. You may need to gently wiggle it free. Finally, remove the entire factory assembly from the engine bay. Take a moment to wipe down the area with a shop towel to remove any debris or oil residue.

Step 2: Transfer the MAF Sensor and Install the Perrin Heat Shield

Remove the MAF sensor from the factory tube using a Phillips screwdriver. Handle it by the plastic body only—do not touch the delicate sensing elements. Place the sensor into the provided boss on the Perrin intake tube, ensuring the O‑ring is seated properly. Tighten the two screws to 2–3 Nm (hand‑tight plus a quarter turn). Reattach the MAF harness connector for now; you may need to route the wiring neatly later.

Install the Perrin heat shield by sliding it into the space behind the headlight and in front of the engine. It fits snugly against the chassis rail. Secure it using the supplied hardware and spacers. Torque the bolts to 8–10 Nm. The heat shield should not contact the hood when closed; check clearance by lowering the hood gently.

Step 3: Mount the Intake Tube

Attach the silicone coupler to the throttle body opening and tighten the T‑bolt clamp slightly—do not fully tighten yet. Slide the Perrin intake tube into the coupler and position the filter end into the heat shield opening. The tube should angle naturally so that the filter sits straight within the shield. Insert the supplied filter onto the tube and tighten its clamp. Make sure the filter is not touching any surrounding components.

Connect the small breather hoses from the engine’s PCV and CCV systems to the barbed fittings on the Perrin tube. Use the supplied rubber hose or adapters if needed. Secure each connection with a small zip tie or spring clamp. Double‑check that all hoses are routed away from moving parts.

Step 4: Secure All Connections and Tighten Clamps

With the tube in place, align it so that there is no stress on the MAF sensor wiring or the coupler. Tighten the throttle body clamp to 4–5 Nm (do not overtighten, as silicone can deform). Tighten the filter clamp snugly. Re‑check all hose connections and ensure that the heat shield is seated firmly. Reconnect the MAF sensor harness and verify that the locking tab clicks into place. Use zip ties to secure the harness away from the intake tube to prevent chafing.

Step 5: Reconnect the Battery and Start the Engine

Reattach the negative battery terminal. Before starting, visually inspect the entire intake system: look for loose clamps, pinched hoses, or any obstructions near the filter. Turn the ignition key to the “ON” position for 5 seconds without cranking to allow the fuel pump to prime and the ECU to reset. Then start the engine. It may idle slightly differently for the first 30 seconds as the ECU re‑learns the air‑fuel trims.

Listen for any whistling or hissing sounds that indicate an air leak. If the engine runs rough, shut it off and verify that the MAF sensor is plugged in and that all couplers are tight. A small amount of steam from the engine is normal as the system adjusts. Let the engine reach operating temperature, then turn it off and recheck all clamps for tightness after the thermal cycles.

Step 6: Test Drive and Verify Performance

Take the BRZ on a 15–20 minute test drive that includes city streets and highway cruising. Pay attention to throttle response—it should feel noticeably sharper than before. The sound will be more pronounced under load, especially between 3,000 and 5,500 RPM. After the drive, reinspect the intake for any loose components. Check the filter for any debris that may have been drawn in during initial installation. If everything looks good, the installation is complete.

Post‑Installation: What to Expect

After installing the Perrin cold air intake, you will immediately notice a deeper intake growl and a more eager throttle. On the dyno, the FA20 typically gains 8–12 horsepower and 6–8 lb‑ft of torque, with the peak gain around 5,500 RPM. The power curve becomes smoother, and the engine feels less restricted, particularly in the mid‑range where daily driving occurs.

One common question is whether a tune is required. While the Perrin intake is designed to work with the factory ECU calibration and will not cause a check engine light, a professional tune (via ECUTek or OpenFlash) can unlock additional gains—often another 5–10 horsepower by optimizing the fuel and ignition tables for the improved airflow. Many owners choose to run the intake without a tune initially and add tuning later. If you do decide to tune, reputable options include Delicious Tuning or an off‑the‑shelf stage 1 calibration from industry leaders.

Be aware that the intake will amplify the sound of the engine’s direct injection system—a ticking noise is normal. Also, the intake filter is more exposed than the stock air box, so avoid driving through deep puddles or using a pressure washer directly on the filter during car washes if you have an oiled filter element.

Maintenance and Longevity

To keep your Perrin cold air intake performing at its best, follow a simple maintenance schedule:

  • Clean the filter every 12,000–15,000 miles (or more often if you drive on dusty roads). For oiled filters, use a dedicated cleaning kit such as the K&N Recharger kit. For dry filters, simply tap out loose dirt and use compressed air from the inside out. Do not use compressed air directly on oiled filters, as it can damage the cotton gauze.
  • Inspect clamps and hoses quarterly – Silicone couplers can loosen over time due to thermal cycling. Check that all T‑bolt clamps are snug (but not overtightened) and that breather hoses are not cracking.
  • Check the heat shield alignment – Ensure the shield has not shifted and still isolates the filter from engine heat. If it rattles, add foam tape to the contact points.
  • Winter considerations – In cold climates, the intake air will be very dense, which can actually increase power. However, be careful on very humid or icy roads—the filter can draw in moisture if water is splashed up from the road. Consider installing a water‑resistant pre‑filter sleeve during wet months.

Many BRZ owners report that the Perrin intake remains trouble‑free for 60,000+ miles with proper care. The high‑quality silicone and aluminum construction resists heat degradation and cracking.

Frequently Asked Questions

Will installing a cold air intake void my warranty?

Under the Magnuson‑Moss Warranty Act, the manufacturer must prove that a modification caused a failure to deny warranty coverage. In practice, a cold air intake is unlikely to cause engine damage, but a dealer may deny a claim related to the intake system itself (e.g., a cracked MAF sensor). Keep your stock parts to swap back if needed.

Do I need to reset the ECU after installation?

Disconnecting the battery for 10 minutes will reset the ECU’s fuel trims and allow it to re‑learn the new airflow characteristics. Most Perrin intakes will not trigger a check engine light, but a reset helps the ECU adapt faster.

The Perrin intake is known for its excellent heat shielding, quiet (but audible) resonance, and easy installation. Injen uses an oiled filter with a larger diameter tube that can shift the power band higher in the RPM range. Mishimoto offers a fully sealed box but is heavier. Grimmspeed’s intake is similar in design but lacks the same level of heat isolation. The best choice depends on your goals—Perrin is a strong all‑rounder that prioritizes sound quality and drivability.

Conclusion

Installing a Perrin cold air intake on your Subaru BRZ is a rewarding modification that delivers both sensory and performance improvements. The installation is straightforward enough for a weekend mechanic, and the result is a more responsive, better‑sounding engine that fully embraces the FA20’s character. Whether you pair it with a tune or enjoy the gains on the stock calibration, the Perrin intake remains a proven, high‑quality upgrade that stands the test of miles and years.