Product Description

The Berklee BS0905 Sports Muffler is designed for reliable street and performance applications. Its free-flow straight-through design reduces exhaust restriction, improving engine breathing, throttle response, and overall efficiency.

Product Specifications

• SKU: BS0905
• Inlet / Outlet: 57mm (2.25")
• Configuration: Centre / Offset
• Body Size: 250mm x 102mm (10" x 4")
• Body Length: 350mm (14")
• Design: Free-flow
• Material: Aluminised Mild Steel
• Fitment: Universal / Reversible
• Manufacture: Australian Made

How Mufflers Work (Technical Overview)

An exhaust muffler controls sound, flow, and backpressure by managing how exhaust gases exit the engine.

As exhaust gases leave the engine, they travel as high-pressure pulses. A muffler reduces noise by disrupting and smoothing these pulses using internal passages, perforated tubes, and sound-absorbing materials.

• Chambered / Reverse Flow Mufflers: Use internal chambers to redirect exhaust flow and cancel sound waves – typically quieter but more restrictive
• Straight-Through (Free Flow): Use a perforated core to maximise flow while absorbing sound
• Hybrid Designs: Balance noise reduction and performance

The Berklee BS0905 features a straight-through free-flow design, allowing exhaust gases to pass with minimal restriction. This helps reduce backpressure, improve scavenging, and maintain engine efficiency while delivering a deeper, sportier exhaust tone.

If a quieter exhaust note is required, a reverse-flow or chambered muffler can be used instead, or combined with a resonator to further reduce noise and refine sound quality.

At operating temperature (~600°C), exhaust gases expand significantly, increasing total volume. A correctly sized muffler like the 57mm (2.25") BS0905 ensures this expanded flow is handled efficiently without creating unnecessary restriction.

Key Features

• Free Flow Design: Improves exhaust flow and reduces backpressure
• Centre / Offset Configuration: Flexible installation for custom systems
• Reversible Design: Can be installed in either direction
• Compact Body: Ideal for tight installations
• Australian Made: Trusted Berklee manufacturing quality

Construction

• Material: Aluminised mild steel for durability and corrosion resistance
• Design: Straight-through perforated core
• Finish: Aluminised coating

Fitment Notes

• Universal muffler – suitable for a wide range of vehicles
• Commonly used in custom exhaust systems and replacements
• Ensure adequate clearance and correct pipe sizing
• Professional installation recommended
• Fitting service available at our Carlton NSW workshop

Recommended With

• Exhaust Clamps (57mm / 2.25") – secure, leak-free installation with no welding required
• Exhaust Pipe (57mm / 2.25") – ideal for custom exhaust fabrication and system repairs
• Mandrel Bends (57mm / 2.25") – maintain smooth airflow for performance exhaust builds
• Exhaust Hangers & Rubber Mounts – reduce vibration and properly support the exhaust system
• Exhaust Gaskets – ensure tight, leak-free connections between components
• Exhaust Sealant – helps prevent exhaust leaks and improves sealing during installation

Engine Airflow & Exhaust Design

Learn more: Engine Airflow & Exhaust Gas Expansion Guide

Emissions & Compliance Notice

This product is intended for off-road or performance use. Always verify emissions and registration compliance in your state or territory before installation.

What’s Included

• 1 x Berklee BS0905 Sports Muffler

Frequently Asked Questions

Is this muffler loud?
The BS0905 delivers a sporty exhaust note without excessive noise, depending on engine size and exhaust setup.

How can I make it quieter?
Adding a resonator or using a reverse-flow muffler will reduce noise and improve comfort.

Is a resonator recommended?
Yes – it helps reduce drone and refine the exhaust tone.

Can it be used in either direction?
Yes, the reversible design allows flexible installation.

Will it fit my vehicle?
This is a universal muffler. Fitment depends on available space and pipe size (57mm / 2.25").

Is this muffler legal for my vehicle?
Check your state or territory regulations to ensure compliance before installation.

What vehicles is this suited for?
Ideal for petrol vehicles, daily drivers, and custom exhaust builds requiring a 57mm system.

Is welding required?
This muffler can be installed using clamps or welded in place, depending on your setup.