Roadster.Blog: MX-5 Roadster ND Mufflers

One of the most important features of a sports car is the exhaust note. during the development of the ND model, Mazda had a dedicated department tasked with creating the ideal sporty car sound. The team was led by Yukifusa Hattori, a man who became slightly obsessed with the MX-5's sound.

"...what was required was a sound with a clear message, something that fully represents the light driving feel that defines the personality of the Mazda MX-5. Perfecting this sound was my job."

- Yukifusa Hattori, NVH Performance Development Dept.

At least 30 prototype intake & exhaust combinations were created based on computer simulations, none of which gave the desired sound. After three months work with little progress, Tsukasa Hoshino from the MX-5's Engine Design Engineering Dept suggested more detailed analysis of how exhaust gas temperatures within the muffler change under various conditions.

Under sudden acceleration the team discovered a 300°C temperature difference between the muffler entrance and exit. Since air density changes with temperature and therefore affects the sound produced, the team were confident they could use this data to redesign the exhaust and produce the sound they were looking for.

After missing several deadlines and annoying engineer colleagues in his pursuit of perfection, the intake and exhaust systems were completed just in time.

"During the test run with the final exhaust system, I told my colleague, who was sitting in the passenger seat, "I can't believe we managed to create this sound. It's just as we visualized it." The cool wind that came through the window reminded me of the change in season, and of the efforts and time spent in pursuit of this glorious sound."

- Yukifusa Hattori

If you're not a fan of the team's work and need a more aggressive sound you need to look to the aftermarket. As well as a louder sound, changing the muffler is a potential easy few kilos of weight saving. The standard muffler is quite large and weighs around 9.3kg, a simpler design can weigh just 1/3 of that. Here are some of your options...