Brands Hatch dB noise levels
Brands Hatch dB noise levels
Author
Discussion

CycleSi

Original Poster:

510 posts

215 months

Friday 15th April 2016
quotequote all
I did a track day recently on the Indy circuit but towards the end of the day got black flagged for exceeding noise limits despite my car and my driving style being consistent all day. I was 93 dB static, but then apparently 5 dB over the drive-by at 4.40pm having been on all day. I know of 13 other cars that were also black flagged and thrown out for noise. This seems a little bizarre to me having done over 30 track days in the past 3 years.

I appreciate circuits are getting stricter, but this is ridiculous.

The reason for my post is to ask where the drive-by sensors on the Brands Indy and Brands GP circuits are as the marshall wouldn't tell me? Other circuits around the UK do let you know so you can 'lift' slightly.

If I were aware then I would adjust my driving style accordingly (and no doubt plenty of others would too).

Any tips/info would be great.....


HaylingJag

2,122 posts

170 months

Friday 15th April 2016
quotequote all

"If I were aware then I would adjust my driving style accordingly (and no doubt plenty of others would too)."


dont you darefurious, if you do you are to hand in your Swedish passportthumbup

mad4amanda

2,410 posts

186 months

Friday 15th April 2016
quotequote all
what was it though? 93 static is low unless you have either under revved the engine at test ( it should be three quarters max rpm ) or the car has a sport button or other device that opens valves in the exhaust at high RPM to make more power and so cheating the euro drive by regs?
BH now has multiple sensors everywhere you would want full throttle so it is no longer possible to lift and fool the sensors along with a new computer which is linked to the local council which shows images of your car . What I can say is that you will have been monitored throughout the day and multiple readings taken and you were given the chance to quieten it down but didn't do enough so you were removed from the day.
Like I say though what car and is it standard and what exhaust/induction if not remember drive by will measure all noise not just exhaust?

CycleSi

Original Poster:

510 posts

215 months

Sunday 17th April 2016
quotequote all
No sport button or anything fancy seeing as it is a Caterham R300 with a K-series engine, but I appreciate the induction noise is also quite loud.

The 93 dB static was at 5250 and it revs to 7500.

"What I can say is that you will have been monitored throughout the day and multiple readings taken and you were given the chance to quieten it down but didn't do enough so you were removed from the day."

I don't think you fully understand what happened as the FIRST and ONLY time I was black flagged was at 4.40pm.
Therefore I can only assume I had been fine all day. No previous warnings or even a mention of being too loud.


Pdelamare

663 posts

150 months

Sunday 17th April 2016
quotequote all
I think atmospheric conditions can affect how far noise travels. I spend a whole day at Silverstone and only got black flagged at the end of the day.

QBee

22,041 posts

166 months

Monday 18th April 2016
quotequote all
I have been 97 db at Cadwell Park static on one warm summer's track day, and 107 on another cool damp one, ie three times as noisy. Same noise meter both times.

Noise testing is very much affected by atmospheric conditions, air temperature and the like. Moist and cool seem to me to be worst, so if I arrive early at the track on a cold damp day, I don't rush to get tested, but instead go to the briefing, take the car out on the sighting laps, and then go and get noise tested, as if i am late arriving. I also carry bolt on cans.

I have also seen a Stuttgart Hoover GT3 fail a noise test at Bedford in similar conditions, getting the same reading as my Rover V8 TVR. The GT3 really was a very quiet car, but they suffer from the induction noise being so close to the exhaust noise.

Which doesn't help you on the drive by, but perhaps explains why you were over the limit in the cooler damper part of the day? You have the local Council, not Brands, to thank for the strict enforcement. Bedford (the track is slightly beyond the back of beyond) suffers from the same council attitude.

E-bmw

12,032 posts

174 months

Monday 18th April 2016
quotequote all
QBee said:
I have been 97 db at Cadwell Park static on one warm summer's track day, and 107 on another cool damp one, ie three times as noisy.
that is 10 as noisy.

97 + 3 is x 2
100 + 3 = 103 is x 2 again = x 4
103 + 3 = 106 is x 2 again = x 8
another + 1 is x 10 the original noise level in total

http://science.howstuffworks.com/question124.htm

Edited by E-bmw on Monday 18th April 15:29

QBee

22,041 posts

166 months

Monday 18th April 2016
quotequote all
That's the strange thing - I know you are right, but it really doesn't sound ten times as noisy from inside the car, with the roof off and the windows down. And my car doesn't at 105 db sound 32 times noisier than a 90 dB Fiesta 1.3.

Perhaps my brain tunes it out somehow, in a similar way to Scottish mountains looking impressive to the naked eye, but like pimples on a photograph. And a person across a room looking well lit to the naked eye, but dimly lit to the camera?

4.7

155 posts

192 months

Monday 18th April 2016
quotequote all
That's deep man.

Mr. H

986 posts

169 months

Monday 18th April 2016
quotequote all
E-bmw said:
QBee said:
I have been 97 db at Cadwell Park static on one warm summer's track day, and 107 on another cool damp one, ie three times as noisy.
that is 10 as noisy.

97 + 3 is x 2
100 + 3 = 103 is x 2 again = x 4
103 + 3 = 106 is x 2 again = x 8
another + 1 is x 10 the original noise level in total

http://science.howstuffworks.com/question124.htm

Edited by E-bmw on Monday 18th April 15:29
This is completely wrong.
You are both confusing sound power and sound pressure. To put it simply:
+3 dB is double the sound power but this is a just noticeable change to human hearing.
+/-10 dB is perceived as doubling/halving the level we hear.

Therefore, 107 dB is twice as loud as 97 dB.

E-bmw

12,032 posts

174 months

Tuesday 19th April 2016
quotequote all
You are quite right, dB is a measure of SPL not noise, I was forgetting the precise definition.

QBee

22,041 posts

166 months

Tuesday 19th April 2016
quotequote all
Thanks for correcting us.....really helpful clap

It also shows how daft the noise testing system is, if my car can be so different on different days at the same track.

git-r

969 posts

221 months

Tuesday 19th April 2016
quotequote all
To the OP :

It was most likely an error, especially if you've not had problems before...

I've been going to brands for 10 years in pretty much the same spec car. The spec changed very slightly about 2 years ago (only a change of turbos - exhaust/induction the same) but have never had a problem. Until December '15 when I was flagged for noise. At the time I was behind a much louder car and think that may have been the cause.

I've since been back in different conditions and been fine.

As mad4amanda will testify smilesmile

git-r

969 posts

221 months

Wednesday 27th April 2016
quotequote all
Just to update this:

I was back at brands on Monday and had problems with noise again.

What I hadn't realised is that the level has been reduced and is reduced further for evening sessions. From memory it's 92 Db driveby in the day and only 90db drive by in the evening.

I tested it at the end of the day when it was just me on track so no question of it being another car.

My car only makes about 92db static but it's the drive by where it fails.

Standard cars like GT3 RS's will fail frown

QBee

22,041 posts

166 months

Wednesday 27th April 2016
quotequote all
It's all very strange.
Bedford is 101dB static and 87.5 dB drive by.
I struggle some times with the 101dB, but have never tripped the drive by meters......

48k

16,069 posts

170 months

Wednesday 27th April 2016
quotequote all
QBee said:
It's all very strange.
Bedford is 101dB static and 87.5 dB drive by.
I struggle some times with the 101dB, but have never tripped the drive by meters......

QBee

22,041 posts

166 months

Wednesday 27th April 2016
quotequote all
He said his car is 92 db sat attic, yet fails a 92 db drive by limit.
My car is 101 db static, yet passes an 87.5 db drive by.

That's what I thought was strange......

git-r

969 posts

221 months

Wednesday 27th April 2016
quotequote all
It may be strange, but it's true frown

Why do you find it strange?

git-r

969 posts

221 months

Wednesday 27th April 2016
quotequote all
Sorry, I mean lots of cars pass static then fail the drive by. Don't they?

TooMany2cvs

29,008 posts

148 months

Wednesday 27th April 2016
quotequote all
QBee said:
He said his car is 92 db sat attic
How's he get it up the loft ladder?