RoadsterSport Race Single Exit Back Box

The RoadsterSport Race Single Exit Back Box is a performance exhaust upgrade specifically engineered for the Mazda MX-5 NC (Mk3). Its track-focused design is ideal for autocross and circuit racing, delivering enhanced throttle response and an aggressive exhaust note. This back box significantly reduces weight compared to the factory system, contributing to improved vehicle dynamics. Constructed from all-stainless steel, this muffler weighs an impressive 3.6kg (8lbs), making it the lightest option in the RoadsterSport range. The internal design features a straight-through configuration measuring 101mm (4″) in diameter and 229mm (9″) in length, utilizing a high-density perforated core. This construction maximizes exhaust flow while keeping sound levels manageable. On a stock vehicle, typical sound measurements range from 85–88dB at 15.2m (50ft), making it compliant with most track day sound restrictions. While optimized for track performance, the RoadsterSport Race Single Exit Back Box can also be a suitable choice for street use when paired with the factory manifold and midpipe. It provides a deep, sporty tone under acceleration that remains relatively subdued during cruising. The single-exit configuration offers a clean and purposeful aesthetic, appealing to drivers seeking simplicity and performance. This back box is an excellent choice for enthusiasts aiming to shed over 9kg (20lbs) from their vehicle's exhaust system, thereby gaining sharper response and a more engaging exhaust sound. Its all-stainless steel construction ensures durability and corrosion resistance.