View Full Version : Exhaust Db's
Cupra Gti Guy
10-06-2004, 22:49
Hello there.
As some of you know I have recently got a new exhaust on my cupra. It is a straight through system with no silencers.
Can anyone tell me if there is a limit as to how loud it can be? I mean is there any sort of fine, or traffic offence for having a really loud exhaust or if the cops are just out to get me, could they do me for breach of the peace?
How can they measure to see if it is over their limit? If they have one?
Is there a legal requirement for road cars to have silencers?
And I know this is a silly one but is there anything to merit points on your lisence? The reason I ask, if I get 3 more points then I am banned and have to re-sit test cause I have only been driving for 18mths and I am only allowed 6 for my first 2 years.
Thanks guys
Andy
Thanks
Andy
There is a limit for noise, don't know the figures tho', mind you most motorbikes seem to get away with it.
If its too loud the cops can hear you from too far away anyway!!!
Seem to remember having trouble with the race exhaust on my caterham when going to tracks - over 95 or 110 dB. Most guys had to run diverters at the tailpipe to try and keep within the limit. I think the road limit would be lower?
I thought it could also fail the MOT for being to loud, at the testers discretion, not a set limit though. They might be able to get you being a public annoyance if its to loud, my mini used to be ear defining but never got pulled for it, you also tend to fall out with everyone in a 5 mile radius of your house when getting home late :D
old 'uns
19-06-2004, 12:14
take it back to who ever fitted it if you get pulled. may be too late by then.ignorance is no excuse
bikers have loud exhausts so blind drivers can hear them @warp speed in built up areas
ibizacupra
20-06-2004, 11:39
I thought it could also fail the MOT for being to loud, at the testers discretion, not a set limit though. They might be able to get you being a public annoyance if its to loud, my mini used to be ear defining but never got pulled for it, you also tend to fall out with everyone in a 5 mile radius of your house when getting home late :D
There is no noise test for MOT... on cars
They cannot fail you for it unless its broken/blowing of simply failing emissions.
Other than track days, I don't think there is a noise level... but would be interested to see if anyones got info to the contrary. - most typically going to be "if a cop can hear you before he see's you" expect to get pulled if they are that way inclined. - Not an endorable offence I would'nt have thought... but a producer and notice to fix might ensue.
MSA testing is @45 degrees to the tailpipe @0,5mtr distance. (db(A))
Common track day levels are 95 db(A), 98 db(A), 105 db(A) depending on venue for info
There is no noise test for MOT... on cars
They cannot fail you for it unless its broken/blowing of simply failing emissions.
Other than track days, I don't think there is a noise level... but would be interested to see if anyones got info to the contrary. - most typically going to be "if a cop can hear you before he see's you" expect to get pulled if they are that way inclined. - Not an endorable offence I would'nt have thought... but a producer and notice to fix might ensue.
MSA testing is @45 degrees to the tailpipe @0,5mtr distance. (db(A))
Common track day levels are 95 db(A), 98 db(A), 105 db(A) depending on venue for info
can be a fail for the MOT if it is loud enough at idle
static noise test is done at 2/3 max rpm the SVA limit is 101db
can be a fail for the MOT if it is loud enough at idle
I was told this buy two MOT test stations, hence I didn't take mine to them and went to somewhere else where it wasn't a problem.
ibizacupra
21-06-2004, 08:33
can be a fail for the MOT if it is loud enough at idle
static noise test is done at 2/3 max rpm the SVA limit is 101db
Not on MOT... They have no test kit
SVA maybe, but thats not exactly an MOT is it..... Was once a legal type approved car :p before we got our sticky little mits on it. :roflmao:
That's because you don't need to prove how loud it is...
From the MOT Manual
Reason for rejection
a silencer in such a condition, or of such a type, that the noise emitted from the vehicle is clearly unreasonably above the level expected from a similar vehicle with a silencer in average condition
HUGO_BOSS
03-07-2004, 13:30
I've done the same thing, i put everything away, and now it so damn loud :thumbup:
Did u meassure it? I'm waiting for next show to measure it, i thik it has to
be somewhere aroud 130-140dB :drool:
u can see a picture... i will take one from the bottom when i get the first oportunity ;)
if u see a cop dont thottle :D
btw. did u update software? How much HP did u get? I know it's little but i'm courious :)
I think your 130-140dBA estimate is way over the top. At 140dBA a single second of exposure can cause hearing damage/loss and at 110dBA ish then you will begin to lose hearing after a minute. It's a logarithmic scale and at 130dBA is when it actually begins to pain your ears.
I hope your journeys are only round the corner to collect the newspaper!
HUGO_BOSS
03-07-2004, 13:45
well... as u wish, 've heard one with 130dB and i can say that my is louder,
maybe the results aren't true if u know what i mean...
i don't even know with what they measure it, but i'll take some picures and
videos and show it to you ;) ql?
and that what u wrote is only a teory ;)
You should measure it from inside the cabin or outside the car. If that is 130-140dBA then you wil be deaf very soon. Of course if they stick the probe right inside the exhaust then you will get a false loud reading cos you don't drive with your head up the exhaust.
Even competition ICE is around this level and I defy you to do regular journeys with such an ICE set-up turned up to max for every journey.
What I wrote is in part theory but is based on real examples. You can search the web for examples of how loud things are and at what thersholds it hurts and when you start to lose hearing.
HUGO_BOSS
03-07-2004, 14:44
:D no.. they dont measure it inside the cabin.
thay measure it behind the exhaust, apr. 0.5m behind it...
i know i would be deaf if it was so loud in the cabin...
well let's wait for the results... :)
oh... i allmost forgot.
I was listening JAMO speaker sistem for home use on more than 100dB
i don't remember precisely... and... my ears are ok ;) :p
Cupra Gti Guy
03-07-2004, 15:57
i was at a sva thingy with a pal of mine in March last year.
Ford Ka standard block, straight through system, no CAT 148db's
Anywho, I am choking to get mine measured to see what it is. I have constantly got ringing in my ears now, and woke up three days after I got the exhaust fitted to find blood in my right ear, may have been co-insidence, but who knows. As long as its over 100db's I am happy.
As for power gains, I have been told with straight through and no CAT depending on how good engine is and petrol you use, should expect about 8bhp increase, feels a bit better off the marque, but not sure if there is any torque increase too.
Andy
Dormouse
04-07-2004, 16:27
oh... i allmost forgot.
I was listening JAMO speaker sistem for home use on more than 100dB
i don't remember precisely... and... my ears are ok ;) :p
Maybe it was damaging the memory centres of your brian then :D
On a serious note, long term exposure (not that long TBH) will destroy the ears abiliy to register frequency band when you are older.
As far as 130-140dB's goes, that's the same as a Jet fighter taking off. And that without earplugs close enough loses it's novely value after the first time :rolleyes:
Don't worry thoughh you only have another 20dB to go to get to 'instant perforation of eardrum' :worship:
Dor.