Complete Guide to Catback Exhaust Systems in Australia

Complete Guide to Catback Exhaust Systems in Australia

Few modifications are as satisfying as a quality exhaust upgrade. The right catback system transforms how your car sounds, improves airflow for measurable power gains, and sheds weight over the factory setup. Best of all, it can be done in a single afternoon. With a range of terminology, brands, and legal considerations to navigate, choosing the right system can feel overwhelming. This guide covers everything you need to know about catback exhaust systems in Australia.

What Is a Catback Exhaust?

The term "catback" refers to the section of your exhaust system that runs from the catalytic converter backwards. This covers everything from the cat outlet to the tailpipe, including the mid-pipe (or centre pipe), any resonators, the muffler, and the tip.

Understanding where catback fits relative to other exhaust options is important:

• Catback exhaust: Replaces everything from the catalytic converter outlet to the tailpipe. Retains the factory cat, so it remains emissions compliant in most cases. The best balance of gains, sound, and compliance.
• Turbo-back exhaust: On turbocharged vehicles, replaces everything from the turbo outlet backwards, including the downpipe and front pipe. Includes or replaces the catalytic converter. Greater power gains but more complex compliance considerations.
• Axle-back exhaust: Only replaces the section from the rear axle to the tailpipe, typically just the muffler and tip. The simplest and cheapest option, but with the least power benefit. Primarily changes sound.

For most performance enthusiasts wanting real gains without regulatory headaches, a catback system is the sweet spot.

Benefits of a Catback Exhaust Upgrade

Power Gains

Factory exhaust systems are designed to balance performance, noise, emissions, and cost, which means they are rarely optimised for flow. A quality catback system with mandrel-bent piping and a free-flowing muffler reduces exhaust backpressure, allowing your engine to expel spent gases more efficiently. Real-world gains typically range from 5 to 20kW at the wheels depending on the platform, with turbocharged vehicles generally seeing the larger end of that range.

Sound Improvement

This is the reason most people upgrade. A catback transforms the exhaust note from factory-subdued to something that genuinely reflects the engine underneath. The degree of change depends on the brand and system. See our sound guide below for a breakdown.

Weight Reduction

Factory exhaust systems are heavy. OEM units on popular performance cars often weigh 15 to 25kg. Quality aftermarket catback systems made from T304 stainless steel or titanium can shed 5 to 12kg, contributing to improved handling balance and acceleration. Racing applications using titanium systems can save even more.

Drone Concerns

One legitimate concern with performance exhausts is cabin drone, that low-frequency resonance at certain RPM ranges, typically experienced at 80 to 110km/h cruise speed. Cheap or poorly designed systems can suffer badly from this. Quality brands engineer their systems to minimise drone through careful resonator placement, pipe diameter selection, and muffler design. The brands recommended below all address drone effectively in their street-focused ranges.

Top Catback Exhaust Brands in Australia

Xforce

Xforce is an Australian brand with strong local support and an excellent reputation for vehicle-specific fitment. Their systems are engineered and tested in Australia, which means they are built for Australian conditions, regulations, and vehicle variants. Xforce offers both street and performance ranges with a clear emphasis on drone-free daily driving.

Best for: Australian-market vehicles including the Holden Commodore, Ford Falcon, locally-spec Subaru WRX, and Nissan variants. Their catback systems for WRX and HSV platforms in particular are highly regarded. Browse Xforce exhaust systems.

Invidia

Invidia is a Japanese brand with exceptional build quality and a strong following in the JDM performance community. Their systems are known for beautiful welds, high-grade T304 stainless construction, and an aggressive but refined exhaust note. Invidia's Q300 and N1 systems are among the most popular catback upgrades for WRX, STi, EVO, and Honda platforms.

Best for: JDM platforms including Subaru WRX/STi, Mitsubishi EVO, Honda Civic/Type-R, and Nissan Silvia/350Z. The Invidia Q300 is a favourite for drivers who want a performance note without excessive volume. Browse Invidia exhaust systems.

Manta

Manta is one of Australia's oldest and most trusted exhaust brands, with decades of experience supplying the local market. Their systems are known for excellent value, wide vehicle coverage, and reliable performance. Manta offers both mild steel and stainless systems, and their stainless range in particular offers impressive durability for the price.

Best for: Everyday performance vehicles and ute platforms. If you're upgrading a Hilux, Ranger, or daily-driven hatchback and want a local Australian brand, Manta delivers excellent bang for buck. Browse Manta exhaust systems.

Borla

Borla is an American brand with a long history in performance exhaust engineering and a global reputation for premium quality. Their systems are constructed from T304 stainless steel with aircraft-quality welds, and Borla's patented straight-through muffler technology delivers a distinctive sound character that is powerful and refined in equal measure. For drivers who want a premium product with a signature exhaust note, Borla is a standout choice.

Best for: Performance vehicles and V8 applications including Mustang, Camaro, and other high-performance platforms available in Australia. Borla systems are known for their bold, deep exhaust tone and top-tier construction quality. Browse Borla exhaust systems.

Exhaust Sound Guide: What Each Brand Sounds Like

Sound is subjective, but here is a general guide to what to expect from each brand's street-focused catback systems:

• Xforce: Deep, throaty, and distinctly Australian muscle-car character on V8 applications. Refined and aggressive on 4-cylinder turbos, with a strong note at wide-open throttle and quiet, controlled sound at cruise. Minimal drone.
• Invidia Q300: Cultured and refined. The resonated tip delivers a subtle, sporty note under normal driving with a more aggressive pop at full throttle. Often described as "the sound the factory should have used." Very low drone, making it an excellent choice for daily driving.
• Invidia N1: Louder and more aggressive than the Q300. Race-inspired rasp at high RPM. Borderline for daily use in noise camera areas and better suited to track or weekend use.
• Manta: Mild to moderate performance note with more of a refined rumble than an aggressive rasp. Suits drivers who want genuine improvement without attracting unwanted attention.
• Borla: Deep, rich, and powerful on V8 applications. Borla's straight-through muffler technology delivers a signature sound that is bold at wide-open throttle and composed during normal driving. A premium note to match the premium construction.

Legal Considerations: State-by-State Overview

Disclaimer: The information below is provided as a general guide only. Exhaust regulations can change, and enforcement varies between jurisdictions and individual officers. Always check with your local state transport authority or a licensed vehicle inspector before fitting an aftermarket exhaust to confirm current requirements in your area.

Exhaust noise laws in Australia vary by state, and compliance can be complex. Here is a simplified overview.

• Queensland: Vehicles must not emit "offensive noise." Police have broad discretion. The general standard for post-1983 vehicles is 90dB(A) at three-quarter maximum RPM. Emissions equipment including the catalytic converter must remain functional. Catback systems that retain the factory cat are generally compliant.
• New South Wales: ADR exhaust noise standards apply. For most post-1983 vehicles, the limit is 90dB(A). Non-compliant exhausts can result in defect notices. Retaining your catalytic converter and staying within dB limits will keep a catback system compliant.
• Victoria: Similar ADR standards apply. VicRoads guidelines state exhausts must not produce "unreasonable noise." Performance exhausts can attract attention during RWC inspections. Xforce and Invidia street systems are typically within compliant ranges.
• South Australia: The 90dB(A) standard applies. SA Police regularly check noise compliance. Quiet catback systems like the Invidia Q300 are well within limits.
• Western Australia: ADR standards are enforced with a similar approach to NSW and Victoria. The catalytic converter must remain in place for road registration.

Key rule of thumb: Retain your catalytic converter, choose a reputable street-focused catback system from a quality brand, and stay within ADR noise limits. If in doubt, have your system measured by a licensed exhaust shop and verify requirements with your local transport authority before proceeding.

Ready to Upgrade Your Exhaust?

Whether you are after the drone-free daily refinement of an Invidia Q300, the Australian-engineered fitment of an Xforce system, or the premium build quality and bold sound of a Borla, we have the right catback exhaust for your vehicle. Browse our full range at the link below and filter by vehicle make and model to find direct-fit options.

Shop Catback Exhaust Systems → carmodsaustralia.com.au/exhausts/cat-back/