I have a trackday coming up, but have no idea how much noise my cars makes.

Limit on the day is 105 dB.


I've used one of our school data loggers to try to test, but it was off the scale (went over 100).


Anyone got any ideas or have any equipment they can use to help me check? Don't want to have wasted any cash.


Am located in Newcastle, but will also be in Glasgow and Leeds before the trackday itself.

Thanks all!

I think there is a free android app you can down load. Not sure about the accuracy though.

You need to measure it 1 metre from the exhaust not right up against. Also different meters measures dB in different ways and give very different results. I used to work with a guy who did noise surveys and he used to talk about dBa and another kind of dB.

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I heard about dBa and dBc. I want to measure the a variety, which it turns out most common noise things don't do.

I'll have another look on the play store, the ones ive used before seem to just be completely random. One didn't change when i clapped right next to the mic.

I have feeling that some tracks measure the noise at more than 1m from the car.

Also I think you need special equipment to measure either dBa or dBc.

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Is your car "road legal" ? As far as I'm aware to get type approval the exhaust note of a car must be measured at <105 dB (happy to be corrected if wrong )

It is indeed road legal, it's passed an MOT and everything.

What you say seems like it makes sense to me. I don't even think it's that loud, I'm just paranoid.

The loudest exhaust I've heard on an octavia was a piper and that was fine for brands hatch. Again similar noise limits. Do you have an aftermarket exhaust?

wondering if a call to the local councils environment noise team would work?

Maybe it would.


It has an aftermarket system, made by longlife.

This one...

http://www.youtube.com/watch?v=sWHsb7MCf2M

If I turn the volume down on my computer it isn't too loud.  You'll be fine.......

Try looking on the registration document to see if it's filled in on that.

Have you not got a track near by?

I believe dB "A" weighted attenuates the input signal as if it was a human ear to essentially measure "how we would hear it"

 

dB "C" weighted is closer to a level frequencey response.

 

So in certain frequencey sounds (such as lower bass notes etc) may be measured to have a greater dB in dB "C" compared to dB "A".

 

So really if you want to know the loudest dB of your exhaust, use a "C" weighted dB meter.

 

 

Might be worth perhaps calling around a few local garages? surely one of them will have a proper dB meter you could quickly use.

 

Also when you do test it, as previously stated try and get it as close as 1 Meter from the tail pipe as possible, and at about a 30 degree angle to the tail pipe, otherwise the readings could be out because of the extra force from the exhaust.

If your in glasgow try giving andy baird at automek a call, they do track day prep so he might have testing equipment or will probably know someone that does

Top tips - dB meters don't just detect exhaust noise but intake as well, so a road legal zorst and a CAI can still put you over a trackday noise limit.

 

Some clutches and gearboxes make more noise engaged but in neutral than disengaged or under drive.

Out of interest my TDI 130 pd makes 69db with a full miltek system measured at Oulton park.

No one complained of excess noise funnily enough lol.

Thanks for the help.

I think I'm going to seek out a local garage who might have some sound measuring equipment. Failing that, I'll find a track prep place or a take it back to the people who made the exhaust. I'm sure they can offer some assistance.

Very unlikely a garage will have a Db meter. You are better talking to someone from a local Motor Club to find out who does their Noise Testing for rallies, or someone from Harewood Hill Climb, as they will have the proper equipment.

An MOT station must have one, surely?  Or do they not test noise levels?  

No they dont. I just went to my local track and asked them to test it.

trackday DB is DbA!

 

It's a lower scale than DbC, so i suspect you pushed it over 100, but on DbA its still perhaps in the low 90s?

 

105 is VERY loud - the kind of loud you'd probably want to put your fingers in your ears - I am thinking V8 with no silencers kind of loud.

dB is a logarthimic scale and so an increase in 3dB equates to a doubling in volume, so to go from say 69 to 100 is actually a big difference.

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105 is VERY loud - the kind of loud you'd probably want to put your fingers in your ears - I am thinking V8 with no silencers kind of loud.

Blimey, that's nearly as loud as 'the wife shouting' loud.  

Thanks guys, you've put my mind at rest a bit. It's certainly not fingers in ears loud at any point in the rev range.