Info: Emissions and Noise Testing

[infotechplus]

It's Easter Sunday so out of deference I'm not doing any work on the Lux today. And since I don't want to waste time doing nothing (heaven forbid) I thought I might do some research into emissions and noise, specifically how it relates to conversions and modifications to vehicles.

There is a lot of misinformation on the net about what you can and can't do. This thread was very interesting, and answers some of the questions:

http://www.toymods.net/forums/showthread.php?t=7230

Thanks to CrUZida for that.

I found two documents that relate to noise generally, and what the Government is trying to do to keep it in check.

These are the Strategic Plan (Parts 1 & 2) from the Motor Vehicle Environment Committee that deal with the National Road Transport Commission Act and the National Environment Protection Council Act. They are typical Government documents but an interesting read in terms of what the National Government hopes to achieve in this area, and I think we as vehicle modifiers need to be aware of where things are heading because they will eventually impact on what we can and can't legally do.

Will there be a time when (due to legislation and/or community feeling) all vehicle modifying will be illegal/unacceptable?

You can download both parts here:

Part One (pdf file, 1718Kb)

Part Two (pdf file, 469Kb)

The NSW Government has also been busy preparing documents that may be the basis of future legislation. The Department of Environment and Conservation have released a 12 page document on managing vehicle noise. Again, it presents a broad picture but there are specifics. For example, it launches straight into the penalties for having or selling knowingly a "noisy" vehicle so that should ring alarm bells for anyone contemplating a change of exhaust system to a more "sporty" one.

Did you know 'defective noise control equipment' is defined as "equipment that allows the emission of more noise than the original noise control equipment fitted by the vehicle manufacturer"? So that means just about any 'sports system' breaches Clause 18 of the Regulation.

In fact, on the next page the document offers this advice to prospective car buyers: To be wary of buying a car where "the exhaust system has been replaced with an excessively loud system such as a sports system".

And for the seller, it points out that "Under section 136 of the Protection of the Environment Operations Act 1997, you must ensure that the exhaust system and other noise control equipment of your vehicle are not defective before selling it. Under clause 6 of the Regulation it is an offence to sell a motor vehicle with a louder exhaust system than the one for which the vehicle was originally designed.

Towards the end of the document it discusses sound systems, and it refers to "offensive noise" coming from those systems. Does this mean that if I'm a lover of jazz and I take offense at your system because it is playing 'heavy metal', it is illegal. It's all open to interpretation by the Police and other authorities but it offers this - "As a guide, if the sound can be clearly heard outside the vehicle and contains low frequency noise, it is likely to be offensive". I think we can all see who is being targetted here!

Noise Emission Standards

This is a direct quote from the NSW RTA (Roads and Traffic Authority):

"The RTA strongly advocates tighter vehicle noise standards. In 2002-03 new noise standards for light and heavy vehicles were introduced. These standards had not been updated for more than 15 years. A new Australian Design Rule, ADR 83/00, was gazetted in March 2003, which introduces more stringent noise limits for new vehicles sold in Australia. The new noise standards will take effect from 2005 and will mean new cars are 3dB quieter, while new trucks and buses will be between 4-7dB quieter than current standards. The new standards include a ‘signature’ noise level that is recorded and unique for each vehicle model. These model specific standards will form the basis for enforcement of noise standards in the future. The signature approach is designed to minimise excessive noise caused by poorly maintained or modified exhausts."

So if you buy a new car and you fit a sports exhaust system to it, as many of us might do, you could be in trouble.

It's a very long document (219 pages) but the Environmental Noise Management Manual published by the RTA in 2001 makes for some interesting reading too.

On page 21 there is a chart of 'noise levels' from everyday living, including jet engines (140dB), average street traffic (75dB) down to libraries (30dB), and on page 25 an pie chart breaking up noise sources from vehicles as follows:

Passenger car noise sources at speeds below 70 km/h (ARRB Research Report ARR314) - Air Intake System (9%), Exhaust System (27%), Tyres (30%), and Engine (34%).

So this says there is more noise generated by tyres than by exhaust systems! I wonder if there'll be a crackdown on noisy tyres? Somehow I don't think so.

As far as future Government legislation is concerned the following quote may form part of it's basis:

"The reduction of noise from individual vehicles is a major factor in reducing traffic noise. For maximum effectiveness vehicle noise management needs to include design, education and enforcement components." [My emphasis].

In 2001 there was a conference in Europe dealing with traffic and noise sponsored by the Swedish National Roads and Transport Research Institute. One of the presenters was Ulf Sandberg who published his paper [pdf, 24 pages, 1078kB) on the Net. It explores some of the myths and realities of traffic and vehicle noise.

His research showed that overall vehicle noise does not necessarily increase as speed increases. In fact, he came to the conclusion that "at low speeds power unit [engine] noise dominates while at high speeds tyre/road noise dominates". He has some graphs which show (as an example) a Volvo F12 truck emits the same level of noise whether it is cruising, accelerating or coasting. So at 90kph it didn't matter whether the truck was coasting or accelerating it still generating the same amount of noise!

So next time you are driving on the freeway and you come across a Police vehicle you can forget dipping the clutch, you're car will probably not make any less noise (although it will probably tone down that sports exhaust you fitted when you did your conversion!)

I also found out that many muffler shops can do noise tests for you. Contact the Motor Vehicle Repair Industry Authority (02 9712 2200) to find a local repairer.

And the final word to the NSW RTA:

"Remember that more noise does not mean more power." (Managing Vehicle Noise, page 6).

Cheers,

Peter

[rob20v]

Some good reading thanks.