Discussion
No. All dB meters are relative, like Dyno's. it will be approximately correct, but that doesn't help if you measure at home 103, the limit is 105, and they measure you at 106.
The only way to do it, from my bike track day experience, is get the vehicle measured at the track you want to go to, note the measurement, then calibrate your home meter to match.
However, if you are well under or over, it will tell you, but that is all
John
The only way to do it, from my bike track day experience, is get the vehicle measured at the track you want to go to, note the measurement, then calibrate your home meter to match.
However, if you are well under or over, it will tell you, but that is all
John
rocketdogbert said:
No. All dB meters are relative, like Dyno's. it will be approximately correct, but that doesn't help if you measure at home 103, the limit is 105, and they measure you at 106.
The only way to do it, from my bike track day experience, is get the vehicle measured at the track you want to go to, note the measurement, then calibrate your home meter to match.
However, if you are well under or over, it will tell you, but that is all
John
Ok thans - i'll download and try it tomorrow - need to be under 105db !The only way to do it, from my bike track day experience, is get the vehicle measured at the track you want to go to, note the measurement, then calibrate your home meter to match.
However, if you are well under or over, it will tell you, but that is all
John
rocketdogbert said:
You need to find to find out from the track how they measure as well.
Some will be at the exhaust tip, some will be half a metre away, some at a 45 degree angle, and the revs they measure it at, it all makes a difference.
John
Good point - i'll try exhaust tip at 4k revs just to get a worse case scenario sense - then i'll get in touch with the track to see how they do it if i'm at a borderline.Some will be at the exhaust tip, some will be half a metre away, some at a 45 degree angle, and the revs they measure it at, it all makes a difference.
John
And tests are always at 1m @ 45degrees at 3/4 revs. Never seen testing at exhaust tips.
What car is it? 105 is a limit that's pretty high. Circuits also have drive by monitors in some cases. The limits on those work differently.
All that based on my experience. You can get a noise meter from Maplins for £30 or so. Not sure how accurate it is, but as suggested above, any meter you have would usefully be calibrated against one at a circuit, but then they are all different anyway.
What car is it? 105 is a limit that's pretty high. Circuits also have drive by monitors in some cases. The limits on those work differently.
All that based on my experience. You can get a noise meter from Maplins for £30 or so. Not sure how accurate it is, but as suggested above, any meter you have would usefully be calibrated against one at a circuit, but then they are all different anyway.
Ive never heard of testing at the exhaust tip either, a mild mannered 95dB car may well read 120dB if tested in that manner!
Drive-by tests are probably only a problem for turbocharged cars, because they behave differently under load. With a normally aspirated car, the static and drive-by tests are relatively linear.
Drive-by tests are probably only a problem for turbocharged cars, because they behave differently under load. With a normally aspirated car, the static and drive-by tests are relatively linear.
Its always at 45 degrees and 50cm away. They never measure at the tip. The thing they touch on the exhaust is not the noise tester, its the measuring stick!
You need to find out what the rules are for engine size, capacity and configuration. They failed my 1200cc air cooled Buell because they insisted on testing it at the same RPM as a bike whose redline was twice that of the Buell. They tested it at 5000rpm when my bike redlined at 7500rpm. They tested a GSXR600 at the same revs, but he redlined at 14,000rpm.
So, I complained to the clerk of the course who asked me to find out the stroke length of my bike. Eventually after much ringing around and waking people up, I found someone who had working internet, and they found that the stroke length of a Buell XB12R is 4.5 inches. Turns out, a twin cylinder bike with a stroke length of 4.5 inches should be measured at 2000rpm! Needless to say, it passed the noise test with flying colours!
You need to find out what the rules are for engine size, capacity and configuration. They failed my 1200cc air cooled Buell because they insisted on testing it at the same RPM as a bike whose redline was twice that of the Buell. They tested it at 5000rpm when my bike redlined at 7500rpm. They tested a GSXR600 at the same revs, but he redlined at 14,000rpm.
So, I complained to the clerk of the course who asked me to find out the stroke length of my bike. Eventually after much ringing around and waking people up, I found someone who had working internet, and they found that the stroke length of a Buell XB12R is 4.5 inches. Turns out, a twin cylinder bike with a stroke length of 4.5 inches should be measured at 2000rpm! Needless to say, it passed the noise test with flying colours!
Been tested several times at Silverstone at exhaust tip (on a bike) when failing drive by test.
All MSV circuits (including Oulton) test static at 45 degrees and 1m, but Donington, not being MSV, do not, they have a similar setup to Silverstone.
Of course, it could of all chnaged since I was retired from track days, but I doubt it. 105dB is not that loud for a bike
John
All MSV circuits (including Oulton) test static at 45 degrees and 1m, but Donington, not being MSV, do not, they have a similar setup to Silverstone.
Of course, it could of all chnaged since I was retired from track days, but I doubt it. 105dB is not that loud for a bike
John
Can you not take the car to your local VOSA test centre?
I do know Snetterton levels...but ialso know that Oulton park are different due to parish restrictions....However.....they do run the Gold Cup which includes ex F1 cars,Indy cars etc...Can be heard from miles away....So I doubt your MX5 will bother the locals toooooo much..
Take a fishing rod just in case you are turned away.....Nice lake on the approach... lol
I do know Snetterton levels...but ialso know that Oulton park are different due to parish restrictions....However.....they do run the Gold Cup which includes ex F1 cars,Indy cars etc...Can be heard from miles away....So I doubt your MX5 will bother the locals toooooo much..
Take a fishing rod just in case you are turned away.....Nice lake on the approach... lol
digger the goat said:
Can you not take the car to your local VOSA test centre?
I do know Snetterton levels...but ialso know that Oulton park are different due to parish restrictions....However.....they do run the Gold Cup which includes ex F1 cars,Indy cars etc...Can be heard from miles away....So I doubt your MX5 will bother the locals toooooo much..
Take a fishing rod just in case you are turned away.....Nice lake on the approach... lol
So a VOSA centre could doma db check? Will look into it if so I do know Snetterton levels...but ialso know that Oulton park are different due to parish restrictions....However.....they do run the Gold Cup which includes ex F1 cars,Indy cars etc...Can be heard from miles away....So I doubt your MX5 will bother the locals toooooo much..
Take a fishing rod just in case you are turned away.....Nice lake on the approach... lol
rocketdogbert said:
No. All dB meters are relative, like Dyno's.
You can get them professionally calibrated though, so if you owned a good quality tester you could have it calibrated and be fairly sure it's working properly.Which of course, means nothing if the track use cheap, uncalibrated meters that could give any old reading.
Mastodon2 said:
You can get them professionally calibrated though, so if you owned a good quality tester you could have it calibrated and be fairly sure it's working properly.
Which of course, means nothing if the track use cheap, uncalibrated meters that could give any old reading.
True enough, I borrowed a pro quality one from my Bro in law when I wanted to prove how loud a fire alarm was in a stairwell at work. 137dB at 10 feet!Which of course, means nothing if the track use cheap, uncalibrated meters that could give any old reading.
John
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