BRZ Exhaust Upgrade Guide: Catback vs Axleback vs Headers (No-Nonsense Buyer's Guide)

Why Exhaust Matters on the BRZ/GR86

The Subaru BRZ and Toyota GR86 are driver's cars at their core—lightweight, balanced, and designed to reward enthusiasts who appreciate the art of driving. But from the factory, the exhaust system is tuned for compliance, not character. Subaru and Toyota prioritize noise regulations, emissions standards, and broad market appeal, which means your stock exhaust is doing its job quietly and conservatively.

For most BRZ and GR86 owners, the exhaust is the first modification—and for good reason. Here's what an aftermarket exhaust actually changes:

Sound: The Boxer Voice

The flat-four boxer engine has a distinctive tone that's muffled by the factory system. An aftermarket exhaust unlocks that signature burble at idle, a raspy midrange, and a rewarding scream at redline. The right exhaust makes every drive more engaging without adding a single horsepower.

Weight Savings: Every Pound Counts

The stock muffler on the BRZ/86 platform weighs around 25–26 pounds. Many aftermarket axlebacks drop that to under 17 pounds, and some track-focused options come in under 10 pounds. On a car that weighs roughly 2,800 pounds, shedding 10–15 pounds from the rear improves weight distribution and rotational mass.

Performance: Managing Expectations

Let's be honest: on a naturally aspirated BRZ or GR86, exhaust upgrades alone won't transform your car into a drag strip monster. Expect modest gains—typically 5–15 wheel horsepower depending on the combination of parts—with most of the improvement felt in the midrange where the stock system is most restrictive. The real power gains come when you combine exhaust work with headers and a proper tune.

The Mod That Sets the Tone

Beyond the tangible benefits, an exhaust upgrade changes your relationship with the car. You'll hear the engine respond to throttle inputs, feel more connected on canyon runs, and actually enjoy sitting at a stoplight. It's the modification that makes every other drive better—which is why it's usually the first one BRZ and GR86 owners make.

Exhaust System Anatomy: What's What

Before you start shopping, it helps to understand how the BRZ/GR86 exhaust system is laid out. Knowing the terminology will help you compare products, understand what you're actually upgrading, and avoid buying parts that don't match your goals.

The exhaust system on the BRZ and GR86 flows from front to back in distinct sections:

Headers (Exhaust Manifold)

The headers bolt directly to the cylinder head and collect exhaust gases from each of the four cylinders. On the FA20 and FA24 boxer engines, the factory headers are a 4-2-1 design—four primaries merge into two collectors, then into one. Aftermarket headers typically feature equal-length tubing to improve exhaust scavenging and unlock power, especially in the midrange. This is where the biggest naturally aspirated power gains live, but it's also where tuning becomes mandatory.

Overpipe / Front Pipe

The overpipe (sometimes called the front pipe) connects the headers to the rest of the exhaust system. On the BRZ/86, this section runs over the rear subframe—hence the name. The factory overpipe includes the primary catalytic converter, which is the main emissions control device. Upgrading to a higher-flow overpipe or catted front pipe can reduce backpressure, but emissions legality varies by state.

Midpipe

The midpipe connects the overpipe to the rear section of the exhaust. On some catback systems, the midpipe includes a resonator to reduce drone (that annoying sustained hum at highway cruising speeds). The diameter and design of the midpipe affect both flow and sound characteristics.

Axleback (Rear Section)

The axleback is everything behind the rear axle—typically the muffler(s), tailpipe, and exhaust tips. This is the easiest section to upgrade and has the biggest impact on sound. Most axleback systems are true bolt-on installations that can be completed in under an hour with basic hand tools.

Visual Breakdown

What's a "Catback" Then?

A catback exhaust replaces everything from the catalytic converter back—meaning the midpipe and axleback together as one complete system. Catback systems offer more comprehensive upgrades than axlebacks alone, with better flow throughout and a more cohesive sound profile. They're the most popular upgrade path for BRZ/GR86 owners who want meaningful improvement without getting into header work or tuning.

Axleback Exhausts: Entry-Level Sound & Style

If you want to transform your BRZ or GR86's sound without breaking the bank or spending a weekend in the garage, an axleback exhaust is the place to start. It's the most accessible exhaust modification—affordable, easy to install, and immediately noticeable every time you start the car.

What You're Actually Replacing

An axleback system replaces the rear-most section of your exhaust: the muffler, tailpipe, and tips. On the stock BRZ/86, this section is intentionally heavy and quiet. The factory muffler is packed with sound-deadening material and weighs around 25 pounds. Most aftermarket axlebacks cut that weight in half while opening up the exhaust note.

The Pros of Going Axleback

• Affordable entry point: Axleback systems typically cost less than catbacks, making them ideal for budget-conscious builds or first-time modifiers.
• Easy installation: Most axlebacks are true bolt-on systems. You'll need a jack, jack stands, basic hand tools, and penetrating oil for the bolts. Many owners complete the install in 30–60 minutes.
• Immediate sound improvement: Even a basic axleback wakes up the boxer engine's character—expect a deeper idle, more pronounced acceleration tone, and actual exhaust presence.
• Weight savings: Dropping 8–15 pounds from behind the rear axle improves weight distribution slightly and reduces unsprung mass.
• No tune required: Since you're not changing anything upstream of the catalytic converter, the ECU doesn't need recalibration.
• Reversible: Keeping your stock exhaust means you can swap back for inspections, lease returns, or resale.

The Cons to Consider

• Minimal performance gains: On an NA BRZ/86, an axleback alone won't add meaningful horsepower. The restriction is further upstream. Expect 1–3 WHP at most—this is primarily a sound and aesthetics modification.
• Potential for drone: Cheaper axlebacks or overly aggressive designs can produce cabin drone at highway speeds (typically 2,500–3,500 RPM). Look for systems with resonated midpipes or built-in drone reduction if you daily drive.
• Sound-only upgrade: If your goal is actual performance improvement, an axleback is just the first step—you'll eventually want to upgrade to a full catback or add headers.

Who Should Buy an Axleback?

An axleback exhaust is the right choice if you:

• Want better sound without spending $1,000+
• Daily drive your BRZ/GR86 and want a moderate, livable tone
• Plan to upgrade to a full catback later (some brands sell matching midpipes)
• Need a simple weekend project with immediate results
• Want to keep the stock catalytic converter and midpipe intact

Sound Levels: What to Expect

Axleback systems range from "slightly louder than stock" to "neighbors will notice." The difference comes down to muffler design:

• Chambered mufflers: Use internal baffles to control sound—typically louder with a deeper tone
• Straight-through / turbo-style mufflers: Less restriction, more volume, raspier at high RPM
• Resonated designs: Include a resonator to cancel specific frequencies and reduce drone

If you're unsure about volume, look for systems described as "street" or "touring"—these prioritize a refined sound over raw volume. Save the straight-pipe tone for dedicated track cars.

Catback Exhausts: The Sweet Spot

For most BRZ and GR86 owners, a catback exhaust hits the perfect balance between cost, performance, sound, and ease of installation. It's the most popular exhaust upgrade on the platform for good reason—you get a complete, cohesive system that transforms the driving experience without requiring a tune or cutting into emissions equipment.

What a Catback Includes

A catback exhaust replaces everything from the catalytic converter flange rearward. This typically includes:

• Front/mid pipe: Connects to the factory catalytic converter outlet
• Resonator section (on some systems): Reduces drone and refines the sound
• Over-axle pipe: Routes exhaust over or around the rear suspension
• Muffler(s): Controls final sound output
• Tips: The visible portion that exits the rear bumper

Because you're replacing the entire rear section as a matched system, catbacks deliver a more refined and intentional sound than mixing and matching individual components.

Why Catbacks Are the Most Popular Choice

Better Flow Throughout

The factory midpipe and muffler are designed with cost and noise compliance in mind—not performance. Aftermarket catbacks typically feature mandrel-bent tubing (smooth interior walls) and less restrictive mufflers. The result is improved exhaust flow from the cat back, which helps the engine breathe better across the entire RPM range.

Meaningful Weight Reduction

A full catback system can save 15–25 pounds compared to stock, depending on materials. Stainless steel systems are durable and affordable; titanium systems can cut weight even further but come at a premium. Either way, you're removing weight from behind the rear axle where it matters most for handling balance.

Cohesive Sound Design

Reputable manufacturers tune their catback systems as complete units—matching pipe diameter, resonator placement, and muffler design to achieve a specific sound profile. This means less guesswork and a more predictable result compared to piecing together an axleback and midpipe from different brands.

No Tune Required

Since catback systems don't modify anything upstream of the catalytic converter, your ECU's air/fuel calculations remain accurate. You can bolt on a catback and drive immediately without scheduling a dyno appointment.

Performance Expectations: Keeping It Real

On a naturally aspirated FA20 or FA24, a catback exhaust alone will net you approximately 5–12 wheel horsepower, with most of the gains in the upper RPM range where the stock system is most restrictive. You'll also notice improved throttle response and a broader powerband feel.

These aren't headline-grabbing numbers, but they're real and measurable. More importantly, the combination of sound, weight savings, and improved flow creates a more engaging driving experience—which is the whole point of owning a BRZ or GR86.

Drone: The Enemy of Daily Driving

Cabin drone is the low-frequency hum that occurs when exhaust sound resonates with your car's interior at certain RPMs—typically 2,500–3,500 RPM, right where you cruise on the highway. It turns a great-sounding exhaust into an exhausting (pun intended) experience on road trips.

To minimize drone, look for catback systems that include:

• Resonated midpipes: A small resonator cancels specific frequencies before they reach the cabin
• Helmholtz chambers: Tuned cavities that absorb drone-causing frequencies
• "Street" or "touring" variants: Many manufacturers offer quieter versions of their popular systems

If you primarily track your car or don't mind an aggressive exhaust, non-resonated systems deliver maximum volume and a rawer tone. Just know what you're getting into before you commit.

Pipe Diameter: 2.5" vs 3"

Most catback systems for the BRZ/GR86 use either 2.5-inch or 3-inch diameter piping. Here's how to choose:

For most naturally aspirated BRZ/GR86 builds, 2.5" is the sweet spot. The FA20 and FA24 don't flow enough air to fully utilize 3" piping without forced induction. If you're planning a turbo or supercharger build, size up to 3" from the start so you don't have to buy twice.

Headers & Front Pipes: Unlocking Real Power

If you're serious about extracting every naturally aspirated horsepower from your BRZ or GR86, headers are where the real gains live. While catbacks and axlebacks primarily change sound, headers fundamentally improve how efficiently your engine expels exhaust gases—and that translates directly to power.

Why Headers Matter So Much on the FA Platform

The factory exhaust manifold on the BRZ/86 is a compromise. It's designed for cost-effective manufacturing, emissions compliance, and adequate (not optimal) performance. The primary tubes are unequal length, the collectors are restrictive, and the overall design prioritizes packaging over flow.

Aftermarket headers address all of these limitations:

• Equal-length primaries: Ensure exhaust pulses from each cylinder arrive at the collector evenly spaced, improving scavenging and reducing reversion
• Optimized tube diameter: Matched to the engine's displacement and RPM range for ideal exhaust velocity
• Merged collectors: Smooth transitions that maintain flow instead of creating turbulence
• Higher-quality materials: Stainless steel construction that resists corrosion and handles heat better than factory cast iron

Types of Headers

4-2-1 Headers

The most common design for the BRZ/86. Four primary tubes merge into two intermediate pipes, which then merge into a single collector. This design offers a broad powerband with strong midrange torque—ideal for street driving and canyon carving where you're not always at redline.

4-1 Headers

All four primaries merge directly into a single collector. This design tends to favor high-RPM power at the expense of some midrange torque. Better suited for dedicated track cars or engines with aggressive cams and high-RPM tuning.

What About the Overpipe / Front Pipe?

The overpipe (front pipe) connects the headers to the rest of the exhaust system. On the BRZ/86, the factory overpipe includes the primary catalytic converter. Upgrading options include:

• High-flow catted front pipe: Replaces the restrictive factory cat with a less restrictive catalytic converter. Maintains emissions compliance in most states while improving flow.
• Catless front pipe: Removes the catalytic converter entirely for maximum flow. For off-road/competition use only. Not emissions legal and will cause a check engine light without a tune.

Power Gains: Real Numbers

Headers are the single biggest bolt-on power modification for a naturally aspirated BRZ or GR86. Here's what you can realistically expect:

These numbers assume a proper dyno tune. Without tuning, you'll see a fraction of these gains and risk running lean, which can cause detonation and engine damage over time.

Tuning: Absolutely Required

Unlike catback exhausts, headers require a tune—no exceptions. Here's why:

• Changed exhaust flow: The ECU's fuel maps are calibrated for factory exhaust restriction. Headers flow significantly more air, requiring fuel adjustments to maintain proper air/fuel ratios.
• O2 sensor readings: The factory oxygen sensors will read differently with headers, potentially causing the ECU to make incorrect adjustments.
• Timing optimization: A proper tune can advance ignition timing to take full advantage of the improved exhaust scavenging.
• Check engine lights: Without a tune, you'll likely trigger CEL codes related to catalyst efficiency or O2 sensor readings.

Plan to budget for a professional dyno tune or an off-the-shelf (OTS) map from a reputable tuner when purchasing headers. The tune is not optional—it's what unlocks the power you paid for.

Installation Complexity

Header installation is significantly more involved than a catback or axleback swap. Expect:

• 4–8 hours of labor for experienced DIYers; longer for first-timers
• Lifting the engine or dropping the subframe on some header designs
• Dealing with seized bolts: The factory exhaust manifold studs are notorious for seizing or breaking. Have penetrating oil, a torch, and extraction tools ready.
• New gaskets: Always use fresh gaskets—never reuse old ones
• Heat management: Aftermarket headers run hotter than stock. Consider heat wrap or a heat shield to protect nearby components.

Many owners opt for professional installation due to the complexity and risk of broken hardware. If you're not comfortable with the job, there's no shame in paying a shop—a botched header install can lead to exhaust leaks, broken studs, and headaches that cost more than professional labor would have.

Who Should Upgrade to Headers?

Headers make sense if you:

• Want maximum naturally aspirated power from your BRZ/GR86
• Already have (or plan to get) a catback exhaust and intake
• Are committed to getting a proper tune
• Understand the installation complexity or have a trusted shop
• Don't need to pass strict emissions testing (or have high-flow cat options available)

If you're still building your foundation—catback, intake, tune—headers are often the final piece that brings everything together for a complete bolt-on build.

Key Specs to Compare: Material, Diameter, Tips & Sound

Once you've decided on the type of exhaust system you want—axleback, catback, or headers—it's time to dig into the specifications that separate good exhausts from great ones. These details affect durability, performance, aesthetics, and most importantly, how your car sounds every time you turn the key.

Material: What Your Exhaust Is Made Of Matters

Exhaust systems endure extreme heat, moisture, road salt, and debris. The material determines how well your exhaust handles these conditions over the long haul.

304 Stainless Steel

The gold standard for aftermarket exhausts. 304 stainless offers excellent corrosion resistance, handles high temperatures without degrading, and maintains its appearance for years. It's heavier than titanium but significantly more affordable.

• Pros: Durable, corrosion-resistant, retains polish, widely available, reasonable cost
• Cons: Heavier than titanium, can discolor with heat (some consider this a pro)
• Best for: Daily drivers, street/track cars, most enthusiasts

409 Stainless Steel

A lower-grade stainless used in some budget exhausts. It resists corrosion better than mild steel but not as well as 304. You may see surface rust or discoloration over time, especially in harsh climates.

• Pros: More affordable than 304, decent corrosion resistance
• Cons: Can develop surface rust, less durable long-term
• Best for: Budget builds, dry climates, cars that won't see winter driving

Titanium

The lightweight champion. Titanium exhausts can weigh 40–50% less than equivalent stainless systems—a significant savings when you're chasing every tenth on track. Titanium also develops a distinctive blue/purple heat discoloration that many enthusiasts love.

• Pros: Extremely lightweight, unique appearance, excellent corrosion resistance
• Cons: Expensive (often 2–3x the cost of stainless), can be more brittle, limited options
• Best for: Dedicated track cars, weight-focused builds, enthusiasts who want the best

Mild Steel (Aluminized)

Found in some OEM and budget aftermarket exhausts. Mild steel is affordable but prone to rust, especially in areas with road salt or high humidity. Aluminized coatings help but don't match stainless longevity.

• Pros: Lowest cost
• Cons: Will rust, shorter lifespan, may need replacement in 3–5 years
• Best for: Temporary setups, extremely tight budgets

Pipe Diameter: Finding the Flow Sweet Spot

Bigger isn't always better. Exhaust pipe diameter needs to match your engine's airflow to maintain exhaust gas velocity. Too small restricts flow; too large kills velocity and can actually hurt low-end torque.

For naturally aspirated BRZ and GR86 builds, 2.5" is the sweet spot. It provides enough flow for a fully built NA engine (headers, intake, tune) without sacrificing the exhaust velocity that helps torque. Only go 3" if you're planning forced induction—and even then, some owners prefer 2.5" for the improved spool characteristics.

Exhaust Tips: The Finishing Touch

Tips are the most visible part of your exhaust and have a surprisingly big impact on your car's rear-end appearance. While tips don't significantly affect performance, they're worth considering for aesthetics.

Tip Styles

• Single-wall: Simple, clean look. The tip is a single layer of material, usually polished or brushed.
• Double-wall: A tip within a tip. The inner wall handles heat while the outer wall stays cooler and maintains its finish better. Looks more substantial.
• Rolled edge: The tip edge is rolled inward for a classic, rounded appearance.
• Slash cut: Angled cut for an aggressive, sporty look.
• Burnt/blue tips: Heat-treated titanium or specially coated stainless with a gradient blue/purple finish. Popular on JDM-style builds.

Tip Diameter

Tips are often larger than the exhaust piping itself—a 2.5" system might have 4" or 4.5" tips. This is purely aesthetic. Larger tips fill out the bumper cutouts better and give a more aggressive appearance. Just ensure the tips fit your bumper's exhaust openings without requiring modification.

Tip Finish

• Polished stainless: Mirror finish, classic look, requires occasional cleaning to maintain shine
• Brushed stainless: Matte metallic finish, hides fingerprints and minor scratches better
• Black coated: Ceramic or powder-coated black finish, stealthy appearance, matches dark exterior trim
• Carbon fiber: Lightweight with distinctive weave pattern, premium appearance

Sound: The Most Subjective Spec

Let's be honest—for most BRZ and GR86 owners, sound is the primary reason to upgrade the exhaust. The factory system is quiet by design, and the boxer engine has a unique tone that aftermarket exhausts can either enhance or ruin depending on your preferences.

Sound Characteristics to Consider

• Volume: How loud is it at idle, cruising, and wide-open throttle? Remember, you'll live with cruising volume daily.
• Tone: Deep and rumbly? Raspy and aggressive? Smooth and refined? The boxer engine naturally has an unequal-length header "burble" from the factory; equal-length headers change this to a smoother, more traditional tone.
• Drone: Low-frequency cabin resonance at steady-state RPMs (usually 2,500–3,500). The enemy of road trips.
• Rasp: A harsh, buzzy quality at high RPM. Some exhausts develop rasp as they break in or at specific RPM ranges.
• Cold start: Many exhausts are significantly louder during cold start before the engine warms up. Consider your neighbors.

How to Research Sound

Never buy an exhaust based on manufacturer descriptions alone. "Deep and aggressive" means different things to different people. Instead:

1. Watch YouTube videos: Search for the specific exhaust on your platform (e.g., "Invidia N1 BRZ sound"). Look for videos with interior and exterior clips, cold start, and highway cruising.
2. Read forum reviews: FT86Club, GR86 forums, and Reddit have extensive exhaust threads with real-world feedback on drone, rasp, and long-term impressions.
3. Listen in person: If possible, attend local meets and listen to cars with the exhaust you're considering. Nothing beats hearing it in real life.
4. Consider break-in: Many exhausts sound different after 500–1,000 miles. Packing material settles, and the tone often mellows slightly.

Resonated vs. Non-Resonated

Many exhaust manufacturers offer both resonated and non-resonated versions of the same system. This single choice has a huge impact on sound character:

If you're unsure, err on the side of resonated. You can always remove a resonator later, but you can't easily add one to a non-resonated system. Many owners who start with loud exhausts eventually swap to quieter setups after living with drone on daily commutes.

Fitment by Generation: FA20 vs FA24

One of the most common mistakes when shopping for BRZ or 86 exhaust parts is assuming everything is cross-compatible. While the first and second generations share a lineage, they're different enough that exhaust fitment is not universal. Understanding the differences between generations ensures you order the right parts the first time.

Generation Breakdown

Note: There was no 2021 model year for the BRZ/86 as the transition between generations occurred.

What's Different Between Generations?

Engine & Header Flange

The most significant change is the engine itself. The FA24 in the second-gen cars is a larger displacement (2.4L vs 2.0L) with different exhaust port spacing. This means:

• Headers are NOT cross-compatible between FA20 and FA24
• Front pipe/overpipe connections may differ
• O2 sensor locations and bung positions can vary

Midpipe & Catback Mounting

The rear subframe and chassis received updates for the second generation, affecting exhaust hanger locations and routing. While some manufacturers have designed catback systems that fit both generations, always verify fitment before purchasing. Don't assume a "BRZ catback" fits your specific year.

Bumper & Exhaust Cutouts

The second-gen BRZ and GR86 have restyled rear bumpers with different exhaust tip cutout sizes and positions. An exhaust designed for the first gen may not align properly with second-gen bumper openings, even if the piping technically bolts up.

First Generation (2013–2020) Fitment Notes

The first-gen platform enjoyed an eight-year production run, making it one of the best-supported chassis in the aftermarket. Key fitment considerations:

• BRZ, FR-S, and 86 are identical: Any exhaust that fits one fits all three. The badges are different; the cars are mechanically the same.
• 2017+ received minor updates: Toyota rebranded the FR-S as the 86 and made minor suspension tweaks, but exhaust fitment remained unchanged from 2013–2020.
• Automatic vs manual: Transmission choice doesn't affect exhaust fitment on this platform.
• Wide aftermarket support: Nearly every major exhaust manufacturer offers first-gen options, and used parts are readily available.

Second Generation (2022+) Fitment Notes

The second-gen platform is newer, so the aftermarket is still expanding. Here's what to know:

• BRZ and GR86 share fitment: Just like the first gen, the Subaru and Toyota twins are mechanically identical where exhaust is concerned.
• FA24 headers are specific: You cannot use first-gen FA20 headers on the second-gen FA24 engine. The ports, spacing, and flange are different.
• Growing aftermarket: Major manufacturers now offer second-gen specific exhausts, but selection is still smaller than first-gen. This is improving rapidly.
• Some catbacks are dual-fit: A handful of manufacturers have engineered catback systems that fit both generations. These are clearly marketed as such—if it doesn't explicitly say it fits 2022+, assume it doesn't.

Cross-Compatibility Summary

How to Verify Fitment

Before clicking "add to cart," take these steps to ensure the exhaust fits your specific vehicle:

1. Check the product listing carefully: Look for explicit year ranges (e.g., "2013–2020" or "2022+"). Vague descriptions like "fits all BRZ" are red flags.
2. Verify with the manufacturer: When in doubt, contact the exhaust manufacturer directly with your year, make, and model.
3. Read reviews from your generation: Look for reviews or forum posts from owners with your specific year to confirm real-world fitment.
4. Ask before you buy: Our team at SubiMods can verify fitment for any exhaust we carry. Reach out if you're unsure—we'd rather answer questions than process returns.

Special Considerations by Model

Scion FR-S (2013–2016)

The FR-S is identical to the 2013–2016 BRZ for exhaust purposes. Scion was discontinued in 2016, and the car was rebranded as the Toyota 86 for 2017+. Any first-gen BRZ/86 exhaust fits the FR-S.

Toyota 86 (2017–2020)

Same platform as the BRZ and FR-S with minor cosmetic and suspension updates. Exhaust fitment is identical to all other first-gen models.

Toyota GR86 (2022+)

The "GR" designation marks the second generation with the FA24 engine. Despite the similar name to the 2017–2020 "86," the GR86 requires second-gen specific exhaust components. Don't confuse the two.

Subaru BRZ tS / Series.Yellow / Other Special Editions

Special editions within each generation (like the BRZ tS or Series.Yellow) share exhaust fitment with their standard counterparts. The special editions received suspension, cosmetic, and interior upgrades—not exhaust changes.

Installation Considerations

One of the best things about exhaust upgrades is that most are genuinely DIY-friendly—especially axlebacks and catbacks. But "bolt-on" doesn't always mean "easy," and some exhaust components require more expertise, tools, and time than others. Here's what to expect so you can decide whether to tackle the install yourself or hand it off to a professional.

Difficulty by Exhaust Type

Tools You'll Need

For most catback and axleback installations, you'll need basic hand tools:

• Socket set: 10mm, 12mm, 14mm are most common for exhaust hardware
• Wrenches: Combination wrenches in the same sizes for tight spaces
• Ratchet with extensions: A 6" extension helps reach recessed bolts
• Penetrating oil: PB Blaster, Liquid Wrench, or similar—essential for stuck hardware
• Jack and jack stands: Or access to a lift. Never work under a car supported only by a jack.
• Rubber mallet: Helpful for persuading stubborn hangers
• Safety glasses: Rust and debris will fall in your face
• Gloves: Exhaust components have sharp edges

For header installations, add:

• O2 sensor socket: Slotted socket designed to fit around the sensor wiring
• Torque wrench: Critical for proper header bolt torque specs
• Anti-seize compound: For O2 sensor threads and header bolts
• Thread chaser or tap set: In case exhaust manifold threads need cleaning
• Exhaust gaskets: Always use new gaskets; never reuse old ones

Axleback Installation: The Easy Win

Axleback swaps are the most beginner-friendly exhaust modification. Here's the general process:

1. Lift the car and secure it on jack stands. Working on ramps is also acceptable for axlebacks.
2. Locate the connection point where the axleback meets the midpipe—usually a clamp or flange with 2–3 bolts.
3. Spray penetrating oil on all hardware and let it soak for 10–15 minutes.
4. Remove the bolts connecting the axleback to the midpipe.
5. Unhook the exhaust hangers from the rubber isolators. A soapy water solution or rubber-safe lubricant helps here.
6. Remove the old axleback and set it aside.
7. Install the new axleback by reversing the process—hangers first, then bolt the connection.
8. Check alignment before fully tightening. Ensure tips are centered in the bumper cutouts.
9. Tighten all hardware and double-check for any exhaust leaks by feeling around connections while the car idles.

Catback Installation: A Bit More Involved

Catback installations follow the same principles as axlebacks but involve more connection points and longer pipe sections:

1. Start from the rear and work forward. Remove the axleback section first, then the midpipe.
2. Support pipe sections as you disconnect them—don't let them hang by a single bolt or hanger.
3. Note hanger positions before removal. Take photos if helpful.
4. Install front-to-back with the new system—start at the catalytic converter connection and work rearward.
5. Use new gaskets if your kit includes them. Even if the old gaskets look okay, fresh gaskets ensure a proper seal.
6. Adjust before tightening to ensure proper tip alignment and adequate clearance from chassis and suspension components.

Header Installation: When to Call a Pro

Headers are a significantly more complex installation that we recommend for experienced DIYers or professional shops. Here's why:

Access Challenges

The boxer engine layout means headers are tucked up against the chassis and firewall. Access is tight, and you'll be working with your arms at awkward angles for extended periods. Some bolts are nearly impossible to see—you'll be working by feel.

Stuck Hardware

Factory exhaust manifold studs and nuts have endured years of heat cycles. They're often seized, rusted, or both. Breaking a stud in the cylinder head turns a weekend project into a machine shop visit.

Torque Specifications

Header bolts must be torqued to spec and often require re-torquing after heat cycles. Improper torque leads to exhaust leaks, which cause driveability issues and potential engine damage from lean conditions.

O2 Sensor Relocation

Aftermarket headers may position O2 sensors differently than stock. You may need sensor extensions or careful wire routing to avoid heat damage.

Tuning Requirement

This is the big one. Headers change exhaust flow characteristics enough that the factory ECU calibration no longer matches. Running headers without a tune causes:

• Check engine lights from O2 sensor readings
• Poor idle quality
• Reduced performance (the ECU pulls timing to compensate)
• Potential long-term engine issues from improper fueling

Common Installation Mistakes to Avoid

Reusing Old Gaskets

Exhaust gaskets are designed to crush and seal once. Reusing them often leads to leaks. New gaskets are inexpensive insurance—always replace them.

Over-Tightening Hardware

More torque isn't better. Over-tightening can warp flanges, strip threads, or crack welds. Follow manufacturer torque specs, and if none are provided, use common sense—snug plus a quarter turn, not gorilla tight.

Ignoring Alignment Before Tightening

Once everything is torqued down, alignment is nearly impossible to adjust. Take your time positioning tips and checking clearances before final tightening.

Forgetting Heat Shields

If your factory exhaust had heat shields, your aftermarket system may need them too—or may include its own. Exhaust heat near fuel lines, brake lines, or the cabin floor is a safety concern.

Not Checking for Leaks

After installation, start the car and carefully feel around all connections (without touching hot pipes). Exhaust leaks are felt as puffs of air. Address any leaks before driving.

Professional Installation: When It Makes Sense

Consider professional installation if:

• You're installing headers (especially your first time)
• You don't have access to a lift or jack stands
• Your factory hardware is heavily rusted or corroded
• The installation requires welding (some systems do)
• You're not comfortable working under a car
• You want the peace of mind of a warranty-backed install

Many performance shops charge 1–2 hours of labor for catback installs and 3–5 hours for headers. Factor this into your budget when planning your build. A professional install also gives you someone to call if issues arise later.

Conclusion: Choosing the Right Exhaust for Your Build

The BRZ and 86 platform rewards thoughtful modification, and exhaust upgrades are one of the most satisfying changes you can make. Whether you're after a subtle improvement in tone, a significant bump in power, or a complete transformation of your driving experience, there's an exhaust setup that matches your goals.

Quick Decision Framework

If you're still weighing options, use this framework to guide your choice:

• Want better sound with minimal investment? Start with an axleback. It's reversible, affordable, and delivers immediate satisfaction.
• Want the best balance of sound, performance, and value? A quality catback system is the sweet spot for most owners. Choose resonated for refinement, non-resonated for aggression.
• Chasing maximum naturally aspirated power? Headers paired with a front pipe, catback, intake, and proper tune represent the full-exhaust build. Budget accordingly and don't skip the tune.
• Building a dedicated track car? Prioritize flow over sound. Titanium construction saves weight, and unrestricted systems maximize every horsepower.
• Daily driving in a noise-sensitive area? Stick with resonated systems and avoid muffler deletes. You can still enjoy an improved exhaust note without becoming "that guy" in your neighborhood.

The Big Picture

Remember that exhaust modifications are part of a larger build strategy. The best results come from complementary upgrades working together:

• Intake + Exhaust: Let your engine breathe freely on both ends
• Exhaust + Tune: Essential for headers, beneficial for full catback systems
• Sound + Performance: The right exhaust delivers both—don't settle for one or the other

Take your time with this decision. Listen to sound clips, read owner reviews, and consider how the exhaust fits your driving habits. A catback system you love will bring a smile to your face every time you start the car. A system that's too loud or too quiet will leave you wishing you'd chosen differently.

We're Here to Help

At SubiMods, we've helped thousands of BRZ and 86 owners find the right exhaust for their builds. Our team has real-world experience with these platforms and can offer honest recommendations based on your specific goals, budget, and use case.

Not sure where to start? Have questions about fitment, sound levels, or supporting mods? Reach out to us at support@subimods.com—we're always happy to talk exhaust.

Start Shopping

Ready to upgrade your BRZ or 86? Browse our curated selection of exhaust systems, intakes, and supporting modifications:

• Shop BRZ / 86 Exhaust Systems
• Shop BRZ / 86 Air Intakes
• Shop All BRZ / 86 Parts

Your BRZ deserves to sound as good as it drives. Let's make it happen.