With the recent events at One Raceway regarding noise limits, I have sought clarification directly from MSA to ensure that members are reading a “single point of truth” when considering the noise limits their cars are subject to.

The Circuit Race Standing Regulations are specific regarding noise limits, including those for Historic Competition. Below is an excerpt from the Circuit Race Standing Regulations 2025:

8.2 NOISE

8.2.1 The Organiser must have a noise-measuring device(s) in the approved location and in operation throughout any Competition. After each Competition, the Competitor of an Automobile that records a sound level between 93 and 95 dB(A) must be advised by the Organiser.

8.2.2 Any Automobile that records in excess of 95 dB(A) during a Competition may be removed from the Track and prohibited from resuming until the Organiser is satisfied that the noise issue has been rectified.

8.2.3 At each Event, at least one official must be nominated as the Judge of Fact – Noise, and their name must be included in the regulations for the Event.

Understanding Noise Measurement at the Track

Taking the above information into account, I want to emphasise that measuring noise at a racetrack is not a fixed or definitive process. Several environmental factors influence noise measurement equipment, including temperature, humidity, cloud cover, wind, fences, and other circuit paraphernalia. Additionally, ambient noise can affect the overall measurement.

How to Avoid Exceeding Noise Limits

As you can see, the guidelines are not straightforward; variations and uncontrollable influences must be considered. The measurement taken at the track is Judge of Fact and is final—it is not negotiable or open to interpretation and must be accepted as correct.

Given that noise level detection is always subject to these uncontrollable variables, our Association advises building a margin into your noise limitation plan. Aim to set your car up to run closer to 93 dB(A) to allow for potential variation, or have a readily available noise mitigation option with you at the track, such as an additional or modified muffler, in case circumstances push your noise level over the limit.

Why This Matters

Our racetracks are under increasing pressure to reduce noise levels, and many overseas tracks already have much lower limits than our 95 dB(A). If Group S cars can limit or eliminate instances of noise level breaches, we will be a category that promoters welcome at their events.

I will leave the comments section closed on this article but will open a Noise Limits Chat where members can engage in sensible discussions (please keep it constructive).

Managing Notifications in Chat Rooms

PLEASE NOTE: In all our chat rooms, you can click on the three dots at the top to mute notifications for a specific chat without muting all chats. These chat rooms are an important communication tool, so I encourage members to mute only the chats that aren’t of particular interest to them.