Why Upgrade to a Borla Cat-Back on the BRZ FA24?

The Subaru BRZ with the FA24 engine delivers a balanced driving experience, but the stock exhaust system is quiet and restrictive. A Borla cat-back exhaust not only unlocks a deeper, more aggressive tone but also improves exhaust flow, which can free up a few horsepower and torque. The best part: you can complete the installation yourself for well under $1,000, saving hundreds in labor costs. Borla’s 304 stainless steel construction, lifetime warranty, and American craftsmanship make it a popular choice for BRZ owners looking for quality sound and durability.

This guide covers every step from gathering tools to final sound checks, so you can install your Borla cat-back exhaust with confidence. Whether you’re a first-time DIYer or a seasoned garage mechanic, the process is straightforward and can be finished in a few hours on a weekend afternoon.

Tools and Materials You’ll Need

Before you get under the car, assemble everything. Having the right tools on hand prevents frustration and keeps the job moving.

Required Tools

  • Borla Cat-Back Exhaust System – confirm the part number matches your 2022+ BRZ (FA24).
  • Socket Set – metric sockets (10mm, 12mm, 14mm, 17mm) and a 3/8″ ratchet.
  • Combination Wrenches – 12mm, 14mm, and 17mm open-end or box-end.
  • Torque Wrench – essential for tightening flange bolts to Borla’s specs (typically 30-35 ft-lbs).
  • Jack and Jack Stands – a low-profile floor jack and a pair of 3-ton stands for safety.
  • Penetrating Oil – like WD-40 Specialist or Liquid Wrench to loosen rusted bolts.
  • Safety Glasses and Gloves – protect against debris and sharp edges.
  • Pry Bar or Exhaust Hanger Removal Tool – helps pop rubber hangers off the studs.
  • Rags and Shop Towels – for cleaning excess oil or grease.

Optional but Helpful

  • Impact Wrench – speeds up bolt removal (use with care on exhaust flanges).
  • Wire Brush – clean rust from studs before reinstalling.
  • Anti-Seize Compound – apply to bolts during reassembly to prevent future corrosion.
  • Smartphone or Camera – take reference photos of the stock exhaust routing.

Borla ships the exhaust with new gaskets and hardware, but double-check that all pieces are present. If anything is missing, contact Borla support before starting.

Preparation: Getting Your BRZ Ready

Preparation determines how smoothly the rest of the job goes. Follow these steps to ensure a safe, efficient install.

Park and Secure the Vehicle

  • Choose a flat, level surface – a garage floor or driveway works best.
  • Engage the parking brake and chock the rear wheels to prevent rolling.
  • Disconnect the negative battery terminal. On the BRZ FA24, this prevents accidental short circuits or sensor resets while you work near the O2 sensors.

Apply Penetrating Oil Early

Exhaust bolts on the BRZ can seize due to heat cycles and road salt. Spray penetrating oil on all exhaust flange bolts (the two nuts at the header joint and the hanger studs) at least 15-20 minutes before you start. For stubborn bolts, apply again and let it soak while you set up the jack.

Jack Up the Rear of the Car

  • Use a floor jack at the factory-recommended rear jack point (center of the rear crossmember).
  • Place jack stands under the rear pinch welds or dedicated lift points on each side.
  • Lower the car onto the stands, ensuring it’s stable. The rear should be high enough for you to slide under comfortably (about 18-20 inches of clearance).
  • Never rely on the jack alone – always use stands.

With the car secure, you now have unobstructed access to the entire exhaust system from the header flange all the way to the tips.

Removing the Stock Exhaust System

The stock BRZ FA24 exhaust comes in two or three sections (mid-pipe and axle-back). Removing it as a single piece is easier if you have a helper, but you can also drop it in sections.

Step 1: Locate and Loosen the Header Flange Bolts

Crawl under the car and find the two large bolts (12mm or 14mm) connecting the front pipe to the exhaust manifold. Use a socket and ratchet (or a wrench if space is tight) to loosen them. They may be tight – apply steady pressure and use penetrating oil if needed. Don’t remove them completely yet; just break them loose.

Step 2: Disconnect the Rear Hangers

There are three rubber hangers supporting the stock system: two near the muffler and one at the rear axle. Using a pry bar or your hands (with gloves), pull the rubber hangers off the metal studs on the exhaust. A little lubricant (soapy water or WD-40) helps slide them off. If the hangers are stubborn, use a dedicated tool to avoid damaging the rubber.

Step 3: Remove the Flange Bolts and Drop the Exhaust

With the hangers free, go back to the header flange. Remove the two bolts and any gasket material. Lower the rear of the exhaust carefully – it may be heavier than expected. Slide the system out from under the car. If the exhaust catches on the sway bar or rear differential, tilt it slightly to clear obstacles. The stock BRZ exhaust weighs about 35-40 pounds; handle with care.

Step 4: Clean the Flange Surface

Use a wire brush or a rag to remove any rust, carbon deposits, or old gasket residue from the header flange. A clean mating surface ensures a leak-free seal with the new Borla gasket.

At this point, inspect the stock muffler hangers. If they are worn or cracked, replace them with new ones (available from Subaru or aftermarket vendors). Good hangers reduce vibration and keep the new Borla firmly in place.

Installing the Borla Cat-Back Exhaust

Borla’s cat-back system for the BRZ FA24 typically includes a mid-pipe and a rear muffler assembly. The pieces connect using slip joints or flanges. Follow these steps for a trouble-free installation.

Step 1: Position the Muffler Assembly

Slide the rear muffler under the car and align the two muffler hangers with the rubber isolators on the chassis. Push the hangers onto the metal studs until they seat fully. A thin coat of silicone spray on the rubber makes this easier. Make sure the exhaust tips are roughly centered in the bumper cutouts – you can adjust later.

Step 2: Attach the Mid-Pipe

Connect the Borla mid-pipe to the muffler assembly using the supplied clamp or bolts (depending on your specific kit). Do not fully tighten yet; leave the connections snug but able to pivot. This will allow you to align the entire system before final torque.

Slide the front flange of the mid-pipe onto the header studs. Install a new gasket between the header flange and the Borla front pipe. Hand-tighten the nuts (usually 12mm) to pull the joint together.

Step 3: Align and Torque All Fasteners

Now go over the entire exhaust system. Adjust the muffler so the tips are evenly spaced in the bumper opening (typically 1/4″ gap on each side). Make sure the mid-pipe isn’t contacting the rear differential brace or the heat shield – allow at least 1/2″ of clearance.

Once alignment is perfect, tighten all fasteners to Borla’s torque specifications:

  • Header flange nuts: 30-35 ft-lbs (do not overtighten, as this can warp the flange).
  • Mid-pipe to muffler clamp: 35-40 ft-lbs (or as indicated on the clamp).
  • Hanger positions: Ensure rubber isolators are fully seated – no tools required, just a firm push.

Re-check that the tips remain centered after torque application – sometimes tightening can shift the system. Adjust as needed.

Step 4: Inspect for Contact and Clearance

Spin the engine over by hand or have a helper gently rock the car while you look for any points where the Borla might touch the chassis, suspension, or heat shields. Common contact points on the BRZ are the rear sway bar end links and the spare tire well. If contact occurs, loosen the affected hanger and re-clock the exhaust slightly.

Final Checks and Testing

You’re nearly done. These final steps confirm the install is safe and leak-free.

Reconnect the Battery and Lower the Car

Reattach the negative battery terminal. Raise the car with the jack, remove the jack stands, and lower it to the ground. Do not start the engine while the car is on stands – the vibration could be dangerous.

Leak Check

With the car on the ground, start the engine and let it idle. Place your hand (carefully!) near each flange joint and around the clamps – you should not feel any exhaust gas escaping. A small puff at startup is normal, but a steady flow indicates a leak. Tighten the affected bolts another 2-3 ft-lbs, or apply more torque if the clamp allows. For persistent leaks, a second gasket may be needed, but that’s rare with Borla systems.

Listen for any rattles, especially at metal-to-metal contact points. If you hear a buzz, shut off the engine and inspect the area. Often it’s a heat shield that needs a slight bend away from the pipe.

Sound Check and Break-In

Take the BRZ for a short test drive through a residential or lightly trafficked area. Accelerate gently and listen for drone at cruising speeds. Borla’s design typically minimizes drone, but some resonance around 2500-3000 rpm is normal during break-in. Drive for 20-30 miles, then re-tighten the flange bolts and clamps after the system has cooled – thermal cycling can loosen fittings.

During the first 100 miles, the exhaust will settle into its final tone as soot builds up inside the packing. Avoid wide-open throttle until break-in is complete to allow the muffler insulation to cure evenly.

Additional Tips for a Seamless Install

Handling Stubborn Bolts

If a header flange nut refuses to budge, use a 6-point socket and a breaker bar – never a 12-point, as it can round the corners. Apply heat from a propane torch (carefully, away from fuel lines) to expand the nut. A few taps with a hammer can break the rust seal. Replace any damaged hardware with high-strength stainless bolts from Borla or Subaru.

Anti-Seize and Thread Locker

Apply anti-seize to the header flange studs during assembly – this will save you headaches later if you remove the exhaust again. For the mid-pipe clamps, use a medium-strength thread locker (Loctite 242) to prevent vibration loosening.

Weight Savings and Performance

The Borla cat-back weighs about 10-15 pounds less than the stock system, which reduces unsprung mass slightly. Combined with the improved flow, you may notice a more responsive throttle and a modest 3-5 hp increase at the wheels, though real-world gains depend on your specific tune and intake. For maximum benefit, pair the exhaust with an ECU tune and a cold air intake – many owners report a combined gain of 15-20 horsepower.

Maintenance and Long-Term Care

Borla’s stainless steel construction resists corrosion, but the finish can dull over time if exposed to winter road salt. Regularly wash the tips and apply a polish like Blue Magic to keep them shiny. Every 12 months, check the hangers for cracking and the clamps for tightness. A quick visual inspection under the car can prevent small issues from becoming larger ones.

If you plan to track your BRZ, consider upgrading to Borla’s optional resonated mid-pipe to reduce drone at high rpm – it’s a direct swap and still keeps the total cost under $1,000.

Conclusion

Installing a Borla cat-back exhaust on your BRZ FA24 is a satisfying DIY project that transforms the car’s personality. With the right tools, a few hours of work, and this guide, you’ll enjoy a sportier sound, a slight performance bump, and the pride of doing it yourself – all for under $1,000. For exact torque specs and fitment details, refer to Borla’s official website and the GR86/BRZ Forums, where the community shares detailed install experiences. For replacement hangers and gaskets, Subaru Online Parts offers OEM components that match perfectly.