Brands Hatch noise limit and 997.1 GT3
Discussion
Nice to have a well informed discussion with input from the other side too. Thank you for contributing.
My one close call came on a cold Spring morning, damp and humid, but I am guessing I would have failed the Brands drive by test on December 2nd if I had managed to get the TVR out of third gear - the weather was just dire.
So, my plan of action is:
1. Go primarily to summer track days to avoid failing the test due to cold damp mornings.
2. Reverse my policy - I usually, as a matter of policy, go straight to the noise test on arrival so that the engine is warm still from the drive to the track. I will now go to the noise test after the sighting laps (or just before if that's not permitted.
3. On autumn winter and spring track days I will rock up mid-morning, thus avoiding noise testing in the worst conditions, as well as all that early rising, waiting around for things to start, damp track due to overnight dew, too many cars on track until 10.30 etc etc
My one close call came on a cold Spring morning, damp and humid, but I am guessing I would have failed the Brands drive by test on December 2nd if I had managed to get the TVR out of third gear - the weather was just dire.
So, my plan of action is:
1. Go primarily to summer track days to avoid failing the test due to cold damp mornings.
2. Reverse my policy - I usually, as a matter of policy, go straight to the noise test on arrival so that the engine is warm still from the drive to the track. I will now go to the noise test after the sighting laps (or just before if that's not permitted.
3. On autumn winter and spring track days I will rock up mid-morning, thus avoiding noise testing in the worst conditions, as well as all that early rising, waiting around for things to start, damp track due to overnight dew, too many cars on track until 10.30 etc etc
_Neal_ said:
Something going on with the meters at Brands - my (quiet-exhausted) Caterham was reading 4-5 db higher than usual on a trackday there in the Autumn on the static test. Most of my trackdays are at MSV circuits, and the Caterham hasn't got any noisier over the past year. Weird. Would meters go out of calibration over a long season?
for the static test the meters are calibrated daily using the sound generator that comes with the meter. we periodically check them against each other as we have 2 and every few months they go back to be checked in a lab. Drive bys are calibrated externally.usually its down to slightly increased revs or the probe on the meter just touching the inside of the pipe and causing a resonance that is picked up by the meter. Or more likely the silencer needs repacking as they do degenerate over time with use and gradually become less effective. Which you might not notice as it is a gradual process and you get used to it.
Edited by mad4amanda on Monday 15th December 20:50
mad4amanda said:
for the static test the meters are calibrated daily using the sound generator that comes with the meter. we periodically check them against each other as we have 2 and every few months they go back to be checked in a lab. Drive bys are calibrated externally.
usually its down to slightly increased revs or the probe on the meter just touching the inside of the pipe and causing a resonance that is picked up by the meter. Or more likely the silencer needs repacking as they do degenerate over time with use and gradually become less effective. Which you might not notice as it is a gradual process and you get used to it.
Its the drive bys that are used to hoof people off the day so how exactly can we be assured that they are as accurate as they should be ? Anecdotal evidence clearly shows that on occasions someone has got it wrong but the right of appeal at a trackday is non existant. You are treated more like a leper.usually its down to slightly increased revs or the probe on the meter just touching the inside of the pipe and causing a resonance that is picked up by the meter. Or more likely the silencer needs repacking as they do degenerate over time with use and gradually become less effective. Which you might not notice as it is a gradual process and you get used to it.
Edited by mad4amanda on Monday 15th December 20:50
Again I`m not having a go and have been on the end of black flags most recently 10 minutes before the day finished. So perfectly ok all day and then all of a sudden , see ya later chap. Whats that all about ?
Can I also ask , you may not know , but who sets the db limit on a certain day ? I see more and more standard regular road cars getting failed which have been perfectly legal to drive to the circuit ? Think GT3 , TVR , Caterham etc
How does it get dealt with when 2 or more cars side by side trip the meter , all black flagged ?
If you think about it for a moment yes it is true that there is no legal limit on noise on the road, in the construction and use or ece certification there is a drive by test which is done at a specified speed hence manufacturers fit vacuum operated and ecu linked devices like the GT3 in question. They fool the test but open up at higher throttle settings releasing more power and torque. The trouble is that in order to manage noise tracks have to disregard whether it is road legal or not at measure total noise.
Some police forces a while back went after modded cars with aftermarket exhausts I think Essex and Norfolk did as it is apparently illegal to modify the car to make more noise but that seams to have died out.
Also bikes are supposed to carry the BS stamp on the silencer in order to be legal but that doesn`t seam to have stopped the popularity of race cans and yes they often have to fit a baffle or 2 for track use.
There are some very loud cars on the road including some I have owned I never had a problem at MOT with my wedge in fact the tester used to say how lovely it sounded. despite being 110 Db at static test! For track use that car needed a pair of additional cans but was road legal.
I guess the thing is if you know your car is loud investigate what you can do to quieten it down and have a back up plan, there are many devices now that can be retro fitted, but remember to look at induction noise too as this will add to the drive by issue .
I hope you all are signed up to this too.......
http://epetitions.direct.gov.uk/petitions/72458?ut...
Some police forces a while back went after modded cars with aftermarket exhausts I think Essex and Norfolk did as it is apparently illegal to modify the car to make more noise but that seams to have died out.
Also bikes are supposed to carry the BS stamp on the silencer in order to be legal but that doesn`t seam to have stopped the popularity of race cans and yes they often have to fit a baffle or 2 for track use.
There are some very loud cars on the road including some I have owned I never had a problem at MOT with my wedge in fact the tester used to say how lovely it sounded. despite being 110 Db at static test! For track use that car needed a pair of additional cans but was road legal.
I guess the thing is if you know your car is loud investigate what you can do to quieten it down and have a back up plan, there are many devices now that can be retro fitted, but remember to look at induction noise too as this will add to the drive by issue .
I hope you all are signed up to this too.......
http://epetitions.direct.gov.uk/petitions/72458?ut...
Thanks to Mad4Amanda for pitching in.
I guess I am particularly surprised as the last time I used the car was few months back at a Brands Hatch evening (where I think the noise limit is slightly less) with no problem at all. I am prepared to accept that as a exhaust system gets older, it gets noisier, but mine hasn't really had the use between the two periods.
I am also prepared to accept that climate/temperature has an effect but you state that even taking that variable into account, my car is well over the limit.
I find it hard to believe that such a variation exists between my previous track outing and last weeks, with the static reading being quite similar (appreciate that contridicts other experiences)
The reason for my original post was to warn others with standard GT3's to be cautious about booking a day at Brands Hatch as it could be over before the end of the sighting laps. This is my third GT3, having tracked them all extensively at the circuit with no issues. This particular GT3 has been to Bedford and Zolder this year (both known for noise issues) and managed all day.
I was fortunate on Friday that a good friend let me drive his MX5 so it didn't totally spoil my day (thanks Raify!) and saved me some fuel!
The staff at Brands Hatch were perfectly courteous about the issue, so I want to be clear that this isn't a rant about how the matter was dealt with, rather a word of warning to other GT3 owners who thing the noise limit at Brands Hatch is sufficient to be able to attend a trackday in a standard car.
I am sympathetic to Brands Hatch for the noise limits that are imposed upon them and will certainly add my name to the petition.
thanks
Simon
I guess I am particularly surprised as the last time I used the car was few months back at a Brands Hatch evening (where I think the noise limit is slightly less) with no problem at all. I am prepared to accept that as a exhaust system gets older, it gets noisier, but mine hasn't really had the use between the two periods.
I am also prepared to accept that climate/temperature has an effect but you state that even taking that variable into account, my car is well over the limit.
I find it hard to believe that such a variation exists between my previous track outing and last weeks, with the static reading being quite similar (appreciate that contridicts other experiences)
The reason for my original post was to warn others with standard GT3's to be cautious about booking a day at Brands Hatch as it could be over before the end of the sighting laps. This is my third GT3, having tracked them all extensively at the circuit with no issues. This particular GT3 has been to Bedford and Zolder this year (both known for noise issues) and managed all day.
I was fortunate on Friday that a good friend let me drive his MX5 so it didn't totally spoil my day (thanks Raify!) and saved me some fuel!
The staff at Brands Hatch were perfectly courteous about the issue, so I want to be clear that this isn't a rant about how the matter was dealt with, rather a word of warning to other GT3 owners who thing the noise limit at Brands Hatch is sufficient to be able to attend a trackday in a standard car.
I am sympathetic to Brands Hatch for the noise limits that are imposed upon them and will certainly add my name to the petition.
thanks
Simon
Yes absolutely and thanks Amanda(!) for contributing. I do fear though that circuits will lose business as the choice now where and who you go with is vast.Also the local tracks in northern France which have become very accessable without all the hooha.
People want to take part and have fun. Not start pricing up new exhaust systems or buying bolt on pipework for a regular car.
I don't really know what the answer is but as the prices continue to increase aswell as the restrictions getting more heavily policed, people will find other places to exercise their pride and joy.
I have posted about the problem previously ( 2 years ago ) on one of my experiences at Donnington very like the op : http://www.pistonheads.com/gassing/topic.asp?t=113...
People want to take part and have fun. Not start pricing up new exhaust systems or buying bolt on pipework for a regular car.
I don't really know what the answer is but as the prices continue to increase aswell as the restrictions getting more heavily policed, people will find other places to exercise their pride and joy.
I have posted about the problem previously ( 2 years ago ) on one of my experiences at Donnington very like the op : http://www.pistonheads.com/gassing/topic.asp?t=113...
Edited by Far Cough on Tuesday 16th December 16:49
mad4amanda said:
for the static test the meters are calibrated daily using the sound generator that comes with the meter. we periodically check them against each other as we have 2 and every few months they go back to be checked in a lab. Drive bys are calibrated externally.
usually its down to slightly increased revs or the probe on the meter just touching the inside of the pipe and causing a resonance that is picked up by the meter. Or more likely the silencer needs repacking as they do degenerate over time with use and gradually become less effective. Which you might not notice as it is a gradual process and you get used to it.
Thanks very much for contributing, that's interesting. I guess it may need repacking but IIRC I did days at Brands and Snetterton in quick succession, and the Brands' meters gave a 4-5 dB higher reading. Lots of variables though, as you say - it's still a very quiet car, and the (aftermarket Raceco) silencer is repackable. usually its down to slightly increased revs or the probe on the meter just touching the inside of the pipe and causing a resonance that is picked up by the meter. Or more likely the silencer needs repacking as they do degenerate over time with use and gradually become less effective. Which you might not notice as it is a gradual process and you get used to it.
Edited by mad4amanda on Monday 15th December 20:50
As an aside, it seems to me that Porsche need to design a quieter exhaust system on the GT3. No excuse for a modern car that's designed with track use in mind, and sold in the UK, to regularly fail noise tests as standard.
_Neal_ said:
As an aside, it seems to me that Porsche need to design a quieter exhaust system on the GT3. No excuse for a modern car that's designed with track use in mind, and sold in the UK, to regularly fail noise tests as standard.
No danger of that. Each successive generation has actually gotten louder. For passing the static or keeping you on an occasional TD there is always the vacuum cap trick, but that is going to cause a lot more heat build up in the back of the car than it is designed for so you would want to keep the revs down even it it didn't strangle the top end of the engine. The best solution is to buy extra bolt on noise reducing exhaust tips (there are threads if you want to do a search). But it is annoying regardless. I only do one or two days a year in the UK these days and spend all of my TD money on road trips to the continent instead. Fabulous as Brands GP is, it still isn't the 'ring or Spa...I have done three track days at Brands recently in my mk1 996 GT3 CS. Car is far from standard - Cup induction kit, including the carbon shroud and Manthey headers, X-over and back boxes. Rev limit of 8600rpm. I pass the static every time, yet I have been black flagged on every single occasion later on in the day. In a deliberate effort to stay on, I would short shift at 7000rpm, yet twice my readings went up by at least 6dB. It is worth noting that on the last occasion I was in a group of 3 cars that I was overtaking. How is BH able to tell that it was me and not the Cooper S race car?
Another poster on here - Houlbt - had the same issue. We had a little dice between his E36 M3 Kumho racer and my GT3 for about 15laps, mercilessly flogging them, yet we did not trigger the drive-by meters. 30mins later he goes out again on his own and registers 106dB and I follow 10mins later with 109dB. How does that work? Needless to say, we both got sent to the naughty corner.
Not happy with the lack of consistency, which is a real shame given that I am all of 15mins away from BH...
Another poster on here - Houlbt - had the same issue. We had a little dice between his E36 M3 Kumho racer and my GT3 for about 15laps, mercilessly flogging them, yet we did not trigger the drive-by meters. 30mins later he goes out again on his own and registers 106dB and I follow 10mins later with 109dB. How does that work? Needless to say, we both got sent to the naughty corner.
Not happy with the lack of consistency, which is a real shame given that I am all of 15mins away from BH...
Not really it sounds like it was done correctly to me ie try and separate the cars and then continue to monitor ? Short shifting will help but as soon as you want to use full power it goes out the window which is why its not an acceptable response to a noise issue and now we ask for a physical change .
Think it comes back to planning ie if you know you are in a loud car have a back up plan .
Also and this goes back to the OP remember as you get dialed in to the track or as happened last Friday the track dries out it will be possible to use more RPM and so the chances of a pull increase .
Interesting for me is the rev limit as that is higher than I expected so static test should be 6450 this could mean it wouldn`t pass the static anyway!
Think it comes back to planning ie if you know you are in a loud car have a back up plan .
Also and this goes back to the OP remember as you get dialed in to the track or as happened last Friday the track dries out it will be possible to use more RPM and so the chances of a pull increase .
Interesting for me is the rev limit as that is higher than I expected so static test should be 6450 this could mean it wouldn`t pass the static anyway!
Edited by mad4amanda on Friday 19th December 07:00
Raify said:
Interesting, both on the weather side of things, and how often and accurately the equipment is calibrated.
I measured 87 on friday, in a car that's measured 83 on every other trackday I can remember getting a reading.
Since dB is a logarithmic unit, it's even more important to have an accurate reading under consistent conditions.
Not much they can do about the weather, but they must have realised something was wrong when they black-flagged about 10% of the customers, most of whom had standard cars.
THe best place to go for Trackdays is DONNINGTON great circuit plus because the planes are flying over all the time you very rarely trouble the db meters & this is coming from someone who lives 10 minutes from Brands, also being a non MSV track the prices are more reasonable & they're more focused on giving you as much track time as possible. I measured 87 on friday, in a car that's measured 83 on every other trackday I can remember getting a reading.
Since dB is a logarithmic unit, it's even more important to have an accurate reading under consistent conditions.
Not much they can do about the weather, but they must have realised something was wrong when they black-flagged about 10% of the customers, most of whom had standard cars.
For what it's worth, static tests produce widely varying results, my 981 Cayman S, standard sports exhaust off, static noise tests this year:
Goodwood 140202 97db
Thruxton 140327 89 db
Castle Combe 140310 97 db
Goodwood 140421 97db
Castle Combe 140626 102db
Rockingham 140701 93db
Castle Combe 140717 100db
Goodwood 140723 98db
Brands Hatch 140919 99db
Snetterton 140925 98db
Goodwood 141007 100db
The Thruxton noise test man is helpful... and there was a GT3 RS 4.0 at Goldtrack's Brands GP day this year and he ran OK
Goodwood 140202 97db
Thruxton 140327 89 db
Castle Combe 140310 97 db
Goodwood 140421 97db
Castle Combe 140626 102db
Rockingham 140701 93db
Castle Combe 140717 100db
Goodwood 140723 98db
Brands Hatch 140919 99db
Snetterton 140925 98db
Goodwood 141007 100db
The Thruxton noise test man is helpful... and there was a GT3 RS 4.0 at Goldtrack's Brands GP day this year and he ran OK
Here is an exhaust tip extension to reduce noise. Rather expensive though!! 
http://www.dynocomp.com/blog/category/dyno-comp-pr...
http://www.dynocomp.com/blog/category/dyno-comp-pr...
mad4amanda said:
Not really it sounds like it was done correctly to me ie try and separate the cars and then continue to monitor ? Short shifting will help but as soon as you want to use full power it goes out the window which is why its not an acceptable response to a noise issue and now we ask for a physical change .
Think it comes back to planning ie if you know you are in a loud car have a back up plan .
Also and this goes back to the OP remember as you get dialed in to the track or as happened last Friday the track dries out it will be possible to use more RPM and so the chances of a pull increase .
Interesting for me is the rev limit as that is higher than I expected so static test should be 6450 this could mean it wouldn`t pass the static anyway!
None of the above answers my question - how do you know it was Think it comes back to planning ie if you know you are in a loud car have a back up plan .
Also and this goes back to the OP remember as you get dialed in to the track or as happened last Friday the track dries out it will be possible to use more RPM and so the chances of a pull increase .
Interesting for me is the rev limit as that is higher than I expected so static test should be 6450 this could mean it wouldn`t pass the static anyway!
Edited by mad4amanda on Friday 19th December 07:00
me and not the other cars?
Also, I know a thing or two about physics - how come we did not trigger the meters when you had two supposedly very loud race cars literally 1m apart, both going for it (how often do you see both an M3 and GT3 flame out on a Dec track day), yet when the two cars go out on their own, they fail?
I know you have to comply with the idiots in the council and all the NIMBYs near-by, thus I am very sympathetic. However what really gets me is the total lack of consistency on behalf of MSV.
Lastly, when you noise test static do you account for the 911's inherent design flaw?
QBee said:
Have you considered the possibility that being side by side may have saved you from the black flag, as they couldn't tell who was the offender?
No sane trackday operator would allow two loons side by side or on each other's tails to trigger the noise meters repeatedly because they could not tell which one of us was the guilty party. We did a 20-odd lap "dice" before we came in. I know what the rules are and I generally play by them. All I am asking for is consistency in their application, which seems to be lacking.Henry Fiddleton said:
I was at Brands yesterday, and my stock Mx5 did 94db!
I even jokingly said its gained 6db from before (numerous other times).
So maybe something strange going on with the equipment or the its something in the air!
I was there in the CSL and had a 98db reading static. the last timeI was there a month ago, it was 92dbI even jokingly said its gained 6db from before (numerous other times).
So maybe something strange going on with the equipment or the its something in the air!
gtsralph said:
For what it's worth, static tests produce widely varying results, my 981 Cayman S, standard sports exhaust off, static noise tests this year:
Goodwood 140202 97db
Thruxton 140327 89 db
Castle Combe 140310 97 db
Goodwood 140421 97db
Castle Combe 140626 102db
Rockingham 140701 93db
Castle Combe 140717 100db
Goodwood 140723 98db
Brands Hatch 140919 99db
Snetterton 140925 98db
Goodwood 141007 100db
The Thruxton noise test man is helpful... and there was a GT3 RS 4.0 at Goldtrack's Brands GP day this year and he ran OK
said 4.0 had an external muffler i was told.Goodwood 140202 97db
Thruxton 140327 89 db
Castle Combe 140310 97 db
Goodwood 140421 97db
Castle Combe 140626 102db
Rockingham 140701 93db
Castle Combe 140717 100db
Goodwood 140723 98db
Brands Hatch 140919 99db
Snetterton 140925 98db
Goodwood 141007 100db
The Thruxton noise test man is helpful... and there was a GT3 RS 4.0 at Goldtrack's Brands GP day this year and he ran OK
bog std 7.2 GT3s struggle with the static test. mine was always 103 even with the vacuum mod which really doesn't help enough. drive by ok
really need an external silencer like the ACT one.
ZX10R NIN said:
THe best place to go for Trackdays is DONNINGTON great circuit plus because the planes are flying over all the time you very rarely trouble the db meters & this is coming from someone who lives 10 minutes from Brands, also being a non MSV track the prices are more reasonable & they're more focused on giving you as much track time as possible.
Said: nobody who owns a GT3. The fact that you cannot hear cars over the planes going over is irrelevant - since they started getting militant on noise there a couple of years back you can't drive a 997 GT3 (nor most 996 GT3s unless you get lucky) on a standard exhaust there unless it is a noisy or test day. I used to go there a couple of times a year, but since the requirement to cork the exhaust or run exhaust mods I don't bother any more.
The most noise permissive UK circuit is Silverstone in my experience.
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