15 replies to this topic

[jn1702]

wots the law reeguarding silencers noise etc? when the police stop u and say your exhaust is to loud sunshine how do you stand? how loud is loud? and what is the legal defininition? decibels etc? how do they prove it's to loud? whats the best course of action? any input appreciated thanks

[Burnard]

OK Some facts first....

NO Police officer has a Decibel meter

NO MOT station has a Decibel meter

NO Main Ministry station has a Decibel meter

Because...THERE IS NO LEGAL DECIBEL LIMIT !

I do...lol

The MOT centres CANNOT fail you on an MOT on noise...no matter how loud it is..

The relevant MOT section says you must NOT have a leaking exhaust or exhaust boxes and it must be gas tight, but nothing about noise...that applies whatever exhaust you have fitted and also if you have NO exhaust fitted (believe it or not)

So in theory you could take your car for an MOT on headers and it must pass as you have no leaks etc etc...

A car does NOT have to have a "standard" manufacturers exhaust on it at all...

But now to the sensible bit...

If I sat outside a Macdonalds revving the whatsits off my engine and I was reported, the police would not do me for a loud exhaust but WOULD do me for something like "public nuisance" or similar...

Noise is not very well covered in the regulations to be honest and its a bit of a grey area...

If you are not a 19 year old chav and being silly then I doubt you will get prosecuted...

after 1992 an MOT centre could fail you for no cats though,but that doesnt apply to earlier cars...

Copied from piston heads website.

Should probably add that that bit about cats isnt true, you dont HAVE to have one, but you will FAIL the emisions test if your car was made after a certaain year and you dont have one, it is posible to pass without it, but difficult.

Exhaust system - complete, secure, without serious leaks and silences effectively

From Direct.gov


But what the *melonsing* hell does 'silences effecivley' mean?


Basically, what im trying to say is there doesnt apear to be any officaial limit.


Chris

Edited by Burnard, 05 March 2009 - 12:13 AM.

[fpsasm]

wots the law reeguarding silencers noise etc? when the police stop u and say your exhaust is to loud sunshine how do you stand? how loud is loud? and what is the legal defininition? decibels etc? how do they prove it's to loud? whats the best course of action? any input appreciated thanks

well.. there are a few points u want to take

(1) by law/dvla , if the MOT tester says that the noise level is unessersary at idle, he could fail it ( me thinks), there is not definate db level...

(2) there might be a law coming out in the next year that any modified silencer with a purpose to make the car louder is illegal

(3) the cheepest way to make ur car louder is to take out teh wool out of teh silencer

(4) its fairlly gaaa... ahh forget it no one listens..

the proper sound of a mini: =D

[Dan]

Piston heads should update their information, or you should stop reading old threads! The MOT rules and the Road Traffic Act have been changed. The rule now is that the car may not produce appreciably more noise than it did when it was made. The rules used to be that a car had to be compared with a similar model to see if it was too loud. Meatheads were abusing this as a loophole and saying that it meant their car had to be compared with a car that had been similarly modified and there was no standard model to compare it with. So the law has been changed and now the car must be compared to what it was like when new. In effect there is no change because there have been rules governing the noise produce by a car for many years, it's just that in the past they were only enforcable during type approval and once a car was on the road it was possible to change it. Technically all cars should have remained with their standard spec but due to the old rules it was not enforcable.

So while there is no written decibel limit for the MOT station or Poilice to go by (unlike the rules for motorcycles which do specify a limit) there is a reference. If you're talking about a Mini here as I hope you are then you are effectively without a leg to stand on, given the volume of the standard pea-shooter exhaust.

[Jammy]

Yey, I get to be uber-clever for once!

2.14 Since 1973, new cars have been required to meet Europe-wide noise limits. Limits have progressively reduced from 82 decibels in 1976 to the current limit of 74 decibels. It would take seven new vehicles to make the same amount of noise as one produced in 1976.

http://www.dft.gov.u...repo3788?page=3

[cambiker71]

Piston heads should update their information, or you should stop reading old threads! The MOT rules and the Road Traffic Act have been changed. The rule now is that the car may not produce appreciably more noise than it did when it was made. The rules used to be that a car had to be compared with a similar model to see if it was too loud. Meatheads were abusing this as a loophole and saying that it meant their car had to be compared with a car that had been similarly modified and there was no standard model to compare it with. So the law has been changed and now the car must be compared to what it was like when new. In effect there is no change because there have been rules governing the noise produce by a car for many years, it's just that in the past they were only enforcable during type approval and once a car was on the road it was possible to change it. Technically all cars should have remained with their standard spec but due to the old rules it was not enforcable.

So while there is no written decibel limit for the MOT station or Poilice to go by (unlike the rules for motorcycles which do specify a limit) there is a reference. If you're talking about a Mini here as I hope you are then you are effectively without a leg to stand on, given the volume of the standard pea-shooter exhaust.

Spot on, the noise is tested at the same rev ranges that the emissions are checked at.

[Ethel]

What about the likes of Z Cars? Does it go by the engine like emissions?

[cambiker71]

What about the likes of Z Cars? Does it go by the engine like emissions?

Depends on how it was registered, if as a modified car then it'll be looked at in the same way as standard, if properly registered (like a kit car with SVA etc) then it would make things a little different, but basically if it's fairly quiet like the engine fitted with a standard(ish) exhaust all will be well, if you go for super loud straight through systems then expect to gain a 'VT30 reason for rejection' sheet.

[brad88]

but what if you take a corsa vxr to get tested with a 'none standard remus backbox on' will they fail it?
EVEN THO the corsa vxr arctic comes standard with a remus backbox! and its the same car but just a different base model
like mini designer or mini 30 etc etc!
brad
(not meaning to sound big headed or anything i genuinely want to know as im sure most of us will agree, there is some big loopholes in not having a 'aftermarket exhaust' on your car!)

[cambiker71]

but what if you take a corsa vxr to get tested with a 'none standard remus backbox on' will they fail it?
EVEN THO the corsa vxr arctic comes standard with a remus backbox! and its the same car but just a different base model
like mini designer or mini 30 etc etc!
brad
(not meaning to sound big headed or anything i genuinely want to know as im sure most of us will agree, there is some big loopholes in not having a 'aftermarket exhaust' on your car!)

It's about the noise emitted not the manufacturers name on the box, if it sounds similar to standard it'll pass, if it's louder than a standard unmodified vehicle it fails. I can't see a loophole in that really.

[brad88]

[/quote]
It's about the noise emitted not the manufacturers name on the box, if it sounds similar to standard it'll pass, if it's louder than a standard unmodified vehicle it fails. I can't see a loophole in that really.
[/quote]

yeh i know that, but if a 'standard vxr arctic' comes with a remus backbox and a 'standrard normal vxr' comes with another make of backbox and you have a remus put onto your 'normal vxr' then really, it is going to sound different to a 'normal standard vxr' that they might test it against but its going to sound the same as a 'normal ARCTIC vxr' if both cars are made as standard like that then how are they modified? so does that mean the 'normal vxr with remus backbox would fail an mot? even thi vauxhall put them on another edition of the vxr as standard?'
once again, im not wanting an argument or anything i just genuinely want to know as i dont see how its going to work with SOME cars,
cheers, brad

[The Matt]

In terms of MOT, it's down to the discretion of the MOT tester. You CAN fail a car for the exhaust being excessively noisy, simple as that. You can also get stopped for a car having an excessively noisy exhaust.

Dan's got it all spot on anwyay (as always)

[cambiker71]

It's about the noise emitted not the manufacturers name on the box, if it sounds similar to standard it'll pass, if it's louder than a standard unmodified vehicle it fails. I can't see a loophole in that really.

yeh i know that, but if a 'standard vxr arctic' comes with a remus backbox and a 'standrard normal vxr' comes with another make of backbox and you have a remus put onto your 'normal vxr' then really, it is going to sound different to a 'normal standard vxr' that they might test it against but its going to sound the same as a 'normal ARCTIC vxr' if both cars are made as standard like that then how are they modified? so does that mean the 'normal vxr with remus backbox would fail an mot? even thi vauxhall put them on another edition of the vxr as standard?'
once again, im not wanting an argument or anything i just genuinely want to know as i dont see how its going to work with SOME cars,
cheers, brad

See above marked in red, it's all you need to worry about, if putting an exhaust from a VXR arctic on a non arctic makes it much louder it fails. I'll repeat again, if it's louder it fails, even if you put a standard exhaust from a different model on to your car. If we're being pedantic about it a normal VXR is a different model to VXR arctic so that loophole doesn't exist.

Edited by cambiker71, 05 March 2009 - 09:28 PM.

[brad88]

thanks for clearing that up....its all i wanted to know...

[Phaeton]

What about the likes of Z Cars? Does it go by the engine like emissions?

If the car goes the SVA route then it has to pass a noise test & yes VOSA do have decibel meter unlike somebody put earlier in the thread. The current specification is a test with the engine running at 3/4 of it's maximum speed, with the probe 200mm from the ground, at a 45 degree angle 0.5m from the end of the exhaust, now in the copy of the manual I have it doesn't state the Db but I 'think' it used to be 93Db but now been reduced to 91Db. Bike engined cars alwayys seem to struggle to get down to this & normally have to put loots of extra baffling in for the test. What the specification will be under IVA no-one knows as we are only working on drafts at the moment with the final one due out in 5 weeks.

Alan...