Bedford and noise limits
14 January 2003, 11:38 AM
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On a recent SIDC day, there were problems with cars meeting the pretty strict noise limits -- 87 dB(A) IIRC.
The RMA web site says that its own days at Bedford are only subject to a 101 dB(A) limit. What's that all about?
http://www.rma-limited.co.uk/calendar.html
The RMA web site says that its own days at Bedford are only subject to a 101 dB(A) limit. What's that all about?
http://www.rma-limited.co.uk/calendar.html
14 January 2003, 12:02 PM
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IIRC - it's 101Db static test and 87Db drive by. The problem @ Bedford was that most cars passed the static and then some failed the drive by. Then, later, the limit was dropped to 85dB which some more cars failed.
Matt.
Matt.
14 January 2003, 01:24 PM
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How is the drive by measured? Do you just drive past a sensor at a given speed? what speed, any gear etc?
Going to a track day and have a stock s2000 so will be OK but am wondering how they do these things.
Going to a track day and have a stock s2000 so will be OK but am wondering how they do these things.
14 January 2003, 01:26 PM
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At bedford their own people (didn't trust the owners not to cheat [img]images/smilies/mad.gif[/img]) thrashed the cars past the sound recorders on the limiter (and upset alot of owners) Most tracks do a static sound test but Bedford was a joke 
14 January 2003, 01:28 PM
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What I don't understand is why they need a static and a drive-by test? Surely if you know the sound level at 0.5m from the exhaust, then you know the sound level at any distance (inverse square law)? I can't see how you can have two cars that pass the static test at the same sound level, but one fails the drive-by test (unless there's a load of induction noise, a hole in the exhaust, or loads of tyre roar).
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14 January 2003, 06:03 PM
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Because it's not a linear thing. For example, a 360 is quite quiet at low revs but turns into a screamer at high revs. If you fail the static badly then they won't let you on. If you only just fail it then they will allow you to try a drive by as this often just passes.
Basically, if you fail the drive by, you're off but they try and limit cars that will obviously fail the drive by before they get onto the circuit by doing a static test first.
Matt
Basically, if you fail the drive by, you're off but they try and limit cars that will obviously fail the drive by before they get onto the circuit by doing a static test first.
Matt
14 January 2003, 11:37 PM
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So, on the driveby (sounds like I'm gonna shoot someone!
) if I put my car into 6th it'll be fine? (it'll be fine anyway but no point thrashing it in front of the sensors & getting booted out).
) if I put my car into 6th it'll be fine? (it'll be fine anyway but no point thrashing it in front of the sensors & getting booted out).
15 January 2003, 01:43 AM
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And it can be changed witout notice
from what I hear
**** them [img]images/smilies/mad.gif[/img]
Must be some better places to go than there!!!!!
Huxley
from what I hear**** them [img]images/smilies/mad.gif[/img]
Must be some better places to go than there!!!!!
Huxley
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