Upgrading your BRZ with a cat-back exhaust system is one of the most popular first steps in performance tuning. It improves exhaust flow, adds a sporty sound, and even sheds weight. Whether you're aiming for more aggressive acoustics or better throttle response, a cat-back exhaust delivers. This guide walks you through the installation process clearly and safely.
What Is a Cat-Back Exhaust System?
A cat-back exhaust system replaces the factory exhaust from the catalytic converter to the exhaust tips. It typically includes the mid-pipe, muffler(s), and dual or single tips. Unlike axle-back systems, a cat-back offers improved airflow from the catalytic converter back.
For the Subaru BRZ, the benefits are clear: reduced back pressure, increased horsepower, and a deeper exhaust tone. According to engineering insights published in SAE International (SAE Paper 2015-01-0996), optimizing post-catalyst exhaust design can yield up to 5–8% gains in torque and horsepower.
Tools and Supplies You’ll Need Before Installation
Before you start, gather the right tools and safety gear:
Essential Tools:
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Socket wrench set (12mm and 14mm sockets)
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Extensions
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Torque wrench
Specialized Tools:
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Exhaust hanger pliers
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Penetrating oil (e.g., WD-40)
Safety Gear:
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Jack stands or ramps
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Work gloves
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Safety glasses
Optional but Helpful:
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Rubber mallet
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Exhaust gasket sealer
These tools will make the installation smoother and reduce the risk of injury or damage.
Preparing Your BRZ for the Installation
Park the vehicle on a level surface. Engage the parking brake and let the exhaust system cool completely.
Lift the BRZ using a hydraulic jack, then secure it with jack stands at all four corners. Spray WD-40 or a similar lubricant on exhaust bolts and rubber hangers. This makes removal smoother and prevents bolt shearing.
Removing the Stock Exhaust System
Begin by removing the bolts connecting the mid-pipe to the overpipe. Then unbolt the rear section from the rubber exhaust hangers.
Remove the factory gaskets carefully. Inspect bolts and retain any reusable hardware. You may need to apply force if the hangers or bolts are seized. A breaker bar can be helpful here.
Common problems include rusted fasteners or misaligned sections. In such cases, patience and proper tools make a big difference.
Installing the Aftermarket Cat-Back Exhaust
1. Test Fit All Components
Place all exhaust parts under the vehicle to check alignment before installation. This prevents fitment issues later.
2. Connect the Mid-Pipe to the Overpipe
Loosely bolt the mid-pipe to the overpipe. This allows minor adjustments during the rest of the installation.
3. Work Your Way Toward the Muffler Tips
Continue assembling the system toward the rear. Mount the muffler and slip it into the rubber hangers without tightening bolts fully yet.
4. Use New Gaskets
Install fresh gaskets between all flanged connections. This ensures a proper seal and helps avoid exhaust leaks.
5. Torque Bolts to Specification
Follow the torque specs provided by your exhaust manufacturer. Overtightening may damage components or strip threads.
6. Align the Exhaust Tips
Make sure both tips are centered and evenly spaced. Poor alignment can cause rattling, rubbing, or cosmetic damage.
Post-Installation Checks and Start-Up
After tightening all bolts, lower the vehicle and start the engine. Listen closely for exhaust leaks. Feel around joints for escaping air.
Pay attention to any rattles or misalignment. A well-installed exhaust should idle smoothly and sound clean. Take a short test drive, then recheck all fasteners.
After 50 to 100 miles of driving, inspect all bolts and hangers again. Heat cycles can cause fasteners to loosen slightly.
Maintenance and Long-Term Considerations
Cat-back systems require minimal upkeep. Clean exhaust tips regularly to avoid soot buildup. Periodically inspect hangers and bolts for wear or corrosion.
If you've paired the cat-back exhaust with an ECU tune, monitor the air-fuel ratio using an OBD-II scanner or gauge. Some systems may trigger CELs if not tuned correctly.
By following this guide, you can enjoy the performance and sound of your new BRZ exhaust with confidence. Whether you're track-prepping or enhancing daily driving, a cat-back install is a rewarding project.
Flashark x UnWrecked Catback Exhaust Giveaway!
We're teaming up with UnWrecked for an exciting giveaway — one lucky winner will receive a Flashark Catback Exhaust System!
How to Enter:
1. Subscribe to the Flashark YouTube channel
2. Leave a comment below: https://www.youtube.com/watch?v=oTuLpm4aSz4&t=955s
Giveaway Period: May 5 – May 18, 2025
*Note: The catback system will be selected based on the winner’s vehicle compatibility.
Good luck, and we can’t wait to see who wins!
