Back Boxes & Mufflers
Performance Mufflers, Back Boxes & Exhaust Tips
The muffler — or back box — defines the sound character of your exhaust system more than any other single component. It's the component that separates a vehicle that sounds purposeful and aggressive from one that sounds antisocial and tiring, and getting the right muffler for your combination and intended use is as much about sound engineering as it is about flow and power. Too quiet and you've spent money on exhaust components for no character gain; too loud and the vehicle becomes unusable for long distances and potentially problematic for MOT and noise regulations.
With 315 products from Flowmaster, Hooker, and Flowmonster — three of the most recognised names in performance mufflers — our back box range covers the full spectrum from deep-noted street mufflers to aggressive track-focused units with minimal restriction and maximum sound character.
Chambered Mufflers — The Classic American V8 Sound
Flowmaster's chambered muffler design has defined the sound of American performance exhaust for decades. The distinctive deep, aggressive tone produced by their patented delta-flow chamber design is instantly recognisable and remains one of the most popular exhaust notes in the performance car community. Chambered mufflers produce their characteristic sound through pressure wave cancellation and reflection within precisely dimensioned chambers — a fundamentally different approach to sound control than absorption-type mufflers, and one that maintains good flow characteristics that don't significantly restrict exhaust output.
Straight-Through and Low-Restriction Designs
Where maximum flow with minimum restriction is the priority — track day cars, drag cars, and vehicles where exhaust note isn't a constraint — straight-through perforated core mufflers with packed absorption material provide the lowest restriction of any muffler design. They produce a more open, raspy sound character than chambered designs, which suits some builds and vehicle types but is typically too aggressive for regular street use.
Exhaust Tips — The Visual Finish
Exhaust tips are the visible termination of the exhaust system and contribute to the overall visual presentation of the vehicle's rear. Chrome, stainless, and burnt titanium finish tips in single-wall and double-wall designs are available in sizes from standard to aggressive, in round, oval, and rectangular profiles to suit different vehicle styles from classic muscle to modern performance.



