As with pretty much all Motorsport events, track days in Ireland have to conform to a pre-defined noise limit. The reason for this is to reduce environmental impact and to help keep Motorsport running. Local Authorities actually have the power to suppress any noise source deemed to be causing a nuisance – in other words, they can shut it down if it’s too loud.
It’s for this reason that all cars have to be noise tested at the track before taking part in a track day, just the same as a race or rally. The noise limit is 105 decibels and any car which exceeds this will not be able to take part and it is a rule that is enforced so consider yourself forewarned!
Here’s an example of the noise test being carried out
How Can I Reduce The Noise?
The vast majority of cars fitted with a silencer in good condition will be under 105 decibels but, that said, some factory systems on standard cars can be
extremely close to the limit. Unsilenced cars will probably fail, so if you’re running a straight-through exhaust you’re going to need to fit a silencer. Larger bore exhausts can also be problematic but there are plenty of add-on silencers you can buy which just slip in or bolt on to your existing tail pipe to reduce noise like the ‘Decibel Slayer’ pictured left.
If you’re able to reduce the noise of your car you can request to be re-tested and if under 105 decibels you will be allowed to take part.
The Noise Test Requirements:
- The engine is to be held at 3/4 of maximum rpm
- Measurements will be made at 0.5m from the end of the exhaust pipe with the microphone at an angle of 45° with the exhaust outlet and at a height of 0.5 to 1.0m above the ground.
- Where more than one exhaust outlet is present, the test will be repeated for each exhaust and the highest reading will be used. In circumstances where the exhaust outlet is not immediately accessible, the test may be conducted at 2.0m from the centre line of the vehicle at 90° to the centre line of the vehicle, with the microphone 1.2m above the ground.
- Measurements will be made outdoors with no large reflecting objects (e.g. walls etc.) within 3.0m (in the 0.5m test) or within 10.0m (in the 2.0m test).
- Background sound levels should be at least 10dB(A) below the measured level.
How Can I Test My Own Noise Level At Home?
The easiest way, although not entirely accurate is a smart-phone app. Follow the same procedure as above and see what you get. Alternatively you could get yourself a digital decibel meter, they start at under €20.00 on Amazon