Exhaust noise limits?

[ihatesissycars]

Here's what the test manual says ref noisey exhausts for cars.

"Reason for rejection.

A silencer in such condition, or of a type, that the noise emitted from the vehicle is clearly unreasonably above the levelexpected from a similar vehicle with a silencer in avergae condition"

So when it comes to mot time for cars its bascially down to the tester opinion which could be anything and vary wildly from one test station to another.

[mgbv8]

And as many of us take very non standard cars to be tested, the tester has no real reference point I suppose. Common sense will prevail eh?

[Paul B]

...When I took it for the last MOT, the guy issued a separate VOSA ticket to say it was a non standard exhaust, but it met the requirements of the MOT at time of testing.

A VOSA ticket?? What sort of a jobsworth is he? What has the type of exhaust got to do with him, as long as it passed the MOT? Did he write a ticket because you don't have original MBG brake pads in too, or tyres?

Last time I looked it wasn't the MOT mans job to check on originality of car parts.

[Ian Anderson]

2 meters of exhaust is a dream!

I have about 13 inch single boxes on each side on the GT40 and they are loud But it also depends on another factor the revs at the max power.

Get the specs on a 4WD max torque cam that maxes at 4500 rpm and say that is what is in it and that max power is at 4000 rpm

Then then have to test at 2/3 rpm of max power - the lower the revs the easier to pass.

Try 2 rear boxes of a 2l Cavalier (One per side) - they got a GT40 quiet enough for a Goodwood track day

Ian

[Ian Anderson]

2 meters of exhaust is a dream!

I have about 13 inch single boxes on each side on the GT40 and they are loud But it also depends on another factor the revs at the max power.

Get the specs on a 4WD max torque cam that maxes at 4500 rpm and say that is what is in it and that max power is at 4000 rpm

Then then have to test at 2/3 rpm of max power - the lower the revs the easier to pass.

Try 2 rear boxes of a 2l Cavalier (One per side) - they got a GT40 quiet enough for a Goodwood track day

Ian

[mgbv8]

Dunno Paul?
He loves the car. I just thought the separate VOSA thing was a bit of insurance for him in case I got home and stuck open pipes on. What does VOSA mean anyway??

[Ian Anderson]

Propbably
Vehicle Office for Silly A55holes

But they think it is Vehicle and Operator Services Agency

See
http://www.vosa.gov.uk/

Ian

[Paul B]

Propbably
Vehicle Office for Silly A55holes

But they think it is Vehicle and Operator Services Agency
ISee
http://www.vosa.gov.uk/

Ian

Dunno Paul?
He loves the car. I just thought the separate VOSA thing was a bit of insurance for him in case I got home and stuck open pipes on. What does VOSA mean anyway??

My MOT guy reckons they are a bunch of pompous stuck up wannabees who failed to get into the military, so found joining VOSA as the next best way to give orders and boss people around. Incompetent idiots who basically haven't got a clue what they are talking about half the time.

If my MOT guy did side notes on everything that is not standard on my Morris I could save him time by writing a list of things that ARE standard, such as the, er, hmm, there are no standard parts. Not one. Oh, maybe the radiator mascot is stock

[john 215]

Hi Gentlemen,
I am a MOT tester,the reason why a pass and advice would be issued is that unlees incredibly noisy then you cant fail for noise level. VOSA do a lot of road side checks now and if the car was to be stopped and the db level measured,they do carry measuring equipment, then they may well check if any remark was made at last MOT,dont forget its all on a data base that we have to enter info at the end of the test and they can look at on a lap top in there van. So basically the guy is just covering his arse and you blame him for that!
Cheers John.

[Paul B]

Hi Gentlemen,
I am a MOT tester,the reason why a pass and advice would be issued is that unlees incredibly noisy then you cant fail for noise level. VOSA do a lot of road side checks now and if the car was to be stopped and the db level measured,they do carry measuring equipment, then they may well check if any remark was made at last MOT,dont forget its all on a data base that we have to enter info at the end of the test and they can look at on a lap top in there van. So basically the guy is just covering his arse and you blame him for that!
Cheers John.

Covering his arse? He should be able to make a decision whether the exhaust volume is acceptible or not and stand by it.

How the exhaust works, or what shape it is, or whether it is original MGB should not come into it, as long as it passes the test.

How many 10 year+ old cars do you test that have original exhaust on, and not some aftermarket copy or reproduction, and do you send notes to Vosa about every one? What is the LAW about changing the exhaust for non standard. Does it say it has to be reported if is not not original?

We are moving into a world where nobody wants to accept responsibilty for anything, everybody wants to pass the buck, and shove the blame elsewhere.

[badger]

I also am an MOT tester and this is my take on things:-

IF I personally want to pass something because I personally feel it's ok, but due to the wording in the testers manual I also think I might get into trouble should the car be pulled or be inspected by VOSA (automatic, following any accident up here by the way) then I'll "pass and advise".
It's purely a means which allows a tester to pass something which he/she may otherwise have been forced to fail if the option weren't there, so don't go automatically having a go at the tester - they may actually be doing you a favour.

[Paul B]

I also am an MOT tester and this is my take on things:-

IF I personally want to pass something because I personally feel it's ok, but due to the wording in the testers manual I also think I might get into trouble should the car be pulled or be inspected by VOSA (automatic, following any accident up here by the way) then I'll "pass and advise".
It's purely a means which allows a tester to pass something which he/she may otherwise have been forced to fail if the option weren't there, so don't go automatically having a go at the tester - they may actually be doing you a favour.

I don't know how things have changed since 2002 when this on-line version was dated, but I see nothing saying anything about it having to be original or whatever. It even says you can use repairs, alternative mounting systems etc. The noise issue is covered quite well, but I still see no reason why you would need or want to tell Vosa that parts are not standard on a car.

Maybe I'm paranoid, but the less info they have on record about our modified cars, the sweeter a world we all live in. The day is drawing close when installing some more petrol will be a main-dealer-only job.

Method of inspection:

1. Examine the condition of the whole exhaust system, including the silencers and mountings, for security, deterioration and completeness
2. With the engine running
a. check the exhaust system for leaks

Note: A durable repair to an exhaust system which effectively prevents leaks is acceptable providing the system is structurally sound
b. assess subjectively the effectiveness of the silencer in reducing exhaust noise to a level considered to be average for the vehicle.

1.
a. A part of the system missing or excessively deteriorated

b. an exhaust system mounting missing, or In such condition that it does not fully support the exhaust system.

Note: An alternative mounting device is acceptable providing the system is secure and the fixing is not likely to fail prematurely-

2.
a. A major leak of exhaust gases from any part of the system

Note: A minor exhaust leak from, for example, a connection joint or a pin hole, is not a Reason for Rejection

b. a silencer in such 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.

[john 215]

Hi,
When testing we dont check if a part is original or not,its simply not part of the test nor is reporting then to VOSA or anyone else,we check if its safe or not and doing the job its supposed to do within the guide lines laid down.Pass and advice is issued to inform the presenter of any faults with the car that may require in the tester opion attention at some point ,border line past in some cases.The doubt should always be shown in the favour of the presenter.You would not beleive the amount of grey areas around the assesment of a things on a MOT.Apart from the tree huggers emission test, it is a very basic test of saftey and roadworthyness on THE DAY the vech is presented.
Most modified cars are in better condition than the average boring eurobox and if done right safer.
As Badgers says some tester may be doing you a favour and if you still dont agree then ask for a appeal form.
VOSA regually hold stop and inspect road stops around here and they are set to be more and more common place in our so called free country
Cheers John.

[Ian Anderson]

John

You say ther are more stop and test jobbies being done?

So when they stop and check noise they know all the requirements and have an open space with no other buildings, vehicles and other items in a 20 meter area behind the vehicle being tested to avoid echo and other such spurius readings? (I'd love to see their test areas!)

Also we could then get into the calibration of the equipment and whether the inspector is qualified as a sound engineeer and thus able to use it and interpret the results accordingly. In otherwords who is checking the checkers as VOSA now seems to think they are the Judge Jury and Executioners.

I agree there should be limits and some of the scooters around my home are well outside acceptable limits. But for example I have a GT40 mid engined car with as much exhaust / silencing system as can be fitted (Cost over £800) and it is marginal at best. Would I like to be able to have it officially tested to prove it is correct - you bet I would and I would then carry the certificate around to stop a "jobsworth" trying to say otherwise. But at the same time I would like to know that a voluntary test would not incur having the vehicle impounded. If suggestions were made on how to better "quieten" the car - even better but I would think not.

Am I outspoken - yes - you should have seen the Mini Hitler that tested my car for SVA and he made the rules up as he went. I then played his game and put all his requirements on the car and it passed. (Does this mean I won?) The only sensible one was that the rear lights did not act as reflectors and I needed to fit some reflectors att he rear of the car. The rest was BS (For example Where in the manusl does it say the wiring loom has to be in cplit conduit? But he insisted on it even though it was a professional loom correctly loom taped!)


Ian
I guess it's time to sell the car and move home so the inspectord don't visit!

[john 215]

Hi Ian,
I agree with you 100% ,i am not the enemy here (i hope not!!) so dont shoot me .Those guys that do the road side checks are the very same people that will come round work and watch me a do full test,something they have to do every 2 years, or put a car in for a test then spring up out of the car park and make sure i have picked up on all the faults they have installed on the car.Little Hitlers is being kind in some cases!!
As the testers manual says a noise greater than a similar vech with a exhaust in good condition (or words to that effect) were the hell am i supposed to find a similar car to yours to listen to or even heard before!Thats what mean by grey areas!
I was actually on a MOT refresher course recently (we have to do one every 5 years) and they told us then there is a big push on road side checks.
Generally speaking as i said yesterday modified cars if done correctly are safer than a lot of every day cars that are only ever checked at MOT time and a pleasure to test. Please beleive as a owner of a modified car i wont fail one unless i have to,i know the work, money and effect that goes into cars like yours.
Cheers John.