Opinions please to quieten my exhaust !

[oap-r]

If you honestly believe that the officer has got it all wrong and you can back this up with documents,MOT's etc rather than taking the expensive route of solicitors and court cases,write to the officer's chief constable.This should be the first and usually most successful point of contact

 

[youngsyp]

Thanks for all you help chaps, some very good and useful points in there.

To be honest, I think the exhaust is too loud as is, whether it's breaking any laws or not. The other half doesn't like it and it makes long journeys stressful. So, I'm going to get it looked at on Friday and go from there. I'll definitely get a silenced de-cat pipe regardless and may go for a transverse box, similar to Carl's design but, coming out the original exit, maybe with 2 passes through a silencer. I have a SPL meter at home so, will check the before and after sound levels in the same/similar circumstances for comparison. I'll get the new rear box made to mate up to the existing system so, I can stick the original back box back on, if I'm not happy with the flow of the new big back box, obviously after plod has seen and approved it.
As far as I'm concerned, that will be the best that I can do (I physically couldn't do anymore to quieten it anyway, due to the shape of the floor pan) so, if it goes to court, I'll make sure that all my facts are in the right place as, I know he's wrong !

Anyway, to answer Steve's question, the actual size of character, imports can have on their plates if "the vehicle does not have European Community Whole Type Approval' and 'the vehicle's construction/design cannot accomodate standard size number plates' is:
Height: 64mm
Width: 44mm
Stroke: 10mm
Space between characters: 10mm

These are the same size rulings that apply to motorbikes.

There is no documentation to state what physically size the plate has to be, unlike standard plates where margin size is stated which will give you the physical plate size. So, lawfully, you can have the plate any size you like, as long as the characters are the correct size.

This info can be found in a document titled 'Current Requirements on the Display of Number Plates', on the dvla website.

If you want information on the road traffic act 1988, go to www.opsi.gov.uk/acts look in the 1988 section and scroll down to the 'Road Traffic Act 1988 C52'.

Hope this helps.

 

[stevepudney]

Anyway, to answer Steve's question, the actual size of character, imports can have on their plates if "the vehicle does not have European Community Whole Type Approval' and 'the vehicle's construction/design cannot accomodate standard size number plates' is:
Height: 64mm
Width: 44mm
Stroke: 10mm
Space between characters: 10mm

These are the same size rulings that apply to motorbikes.

There is no documentation to state what physically size the plate has to be, unlike standard plates where margin size is stated which will give you the physical plate size. So, lawfully, you can have the plate any size you like, as long as the characters are the correct size.

This info can be found in a document titled 'Current Requirements on the Display of Number Plates', on the dvla website.

If you want information on the road traffic act 1988, go to www.opsi.gov.uk/acts look in the 1988 section and scroll down to the 'Road Traffic Act 1988 C52'.

Hope this helps.

Paul, it wasn't a question as such, I know those details and have had a printed copy of the regulations under the carpet in the boot of my car along with the original square import plate for near on 5 years.

It was more of a "are you sure your plate dimesions are legal"

The majority of what you say above is true BUT the the bit

There is no documentation to state what physically size the plate has to be

is wrong, in the correct document it states

Size and spacing of characters: special cases
14A. - (1) This regulation applies in relation to any vehicle imported into the United Kingdom which -


(a) does not have European Community Whole Vehicle Type Approval; and

(b) is so constructed that the area available for the fixing of the registration plate precludes the display on the plate of a registration mark in conformity with the requirements of regulation 14.


(2) In relation to a vehicle to which this regulation applies -



(a) each character in the registration mark must be 64 millimetres high;

(b) the width of each character of the mark, other than the letter "I" and the figure "1", must be 44 millimetres;

(c) the width of every part of the stroke forming a character in a mark must be 10 millimetres;

(d) the spacing between any two characters within a group must be 10 millimetres;

(e) the vertical spacing between groups of characters must be 5 millimetres;

(f) the width of a margin between the mark and the top and lateral sides of the registration plate must be not less than 5 millimetres;

(g) the space between the bottom of the mark and the bottom of the registration plate must be not less than 13 millimetres; but, within that space, the space between the bottom of the mark and the top of the name and postcode of the person by whom the plate was supplied must be not less than 5 millimetres."[3]

Point's F & G above will determine the final size of your plate.

I have had a plate of 82mm x 309mm on the front of my car for the last 5 years and have been stopped twice concerning the plate, the second time the copper actually had a tape measure out and was measuring the bloody thing in the rain, I then shuffed the paperwork under his nose and told him the plate was on the car when I bought it, he read the document breifly then got off his knees and scurried back into the hole he came from.

Steve

 

[gtirx2]

I still can not find this info on plate sizes can someone please post up a link.

 

[stevepudney]

I still can not find this info on plate sizes can someone please post up a link.

Click here

 

[gtirx2]

Thanks mate

 

[youngsyp]

Paul, it wasn't a question as such, I know those details and have had a printed copy of the regulations under the carpet in the boot of my car along with the original square import plate for near on 5 years.

It was more of a "are you sure your plate dimesions are legal"

The majority of what you say above is true BUT the the bit

is wrong, in the correct document it states



Point's F & G above will determine the final size of your plate.

I have had a plate of 82mm x 309mm on the front of my car for the last 5 years and have been stopped twice concerning the plate, the second time the copper actually had a tape measure out and was measuring the bloody thing in the rain, I then shuffed the paperwork under his nose and told him the plate was on the car when I bought it, he read the document breifly then got off his knees and scurried back into the hole he came from.

Steve

Steve, that's very interesting as I took those details from the specific document on the DVLA website and struggled to find those. There was no mention of points (f) and (G) anywhere on it !

However, I'm pretty sure that I'm 'legal' with my one as, it does have a border of some thickness around the front plate, which would be the only one in question with this new information. I'm going to the MOT place today to get the defect notice stamped by them and, I'll take the DVLA document with me just in case !

Thanks for the info.

Paul

 

[youngsyp]

Mmm, I've just found this and think it could apply with regard to exhaust noise level. Look for row 13 in the Schedule 1 table:

http://www.opsi.gov.uk/si/si2004/20040623.htm

Although, not sure if this only applies to Northern Ireland........ nope, it applies to the UK as a whole as, there's a separate document of England !

Paul

 

[campbellju]

Good find.

So straight through exhausts fail an MOT and even with a silencer you need to pass a 101dB static noise test or in theory it will still fail.

 

[youngsyp]

This is the thing, the MOT is extremely subjective. Taken from here: http://www.ukmot.com/

'Method of inspection':

"assess subjectively the effectiveness of the silencer in reducing exhaust noise to a level considered to be average for the vehicle"

'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"

This is why I think the area is so 'grey'. My car has a valid MOT with the test taken with the car as is. In my view, plod shouldn't have a case to answer, if this ever went to court. He's not a DOT approved MOT tester so, how can he deem my exhaust as a 'defect' ?! Surely their decision over rules his ?!

It's interesting that the static noise test, is measured with an 'A' weighting, and not the usual 'C' weighting too ?!

Anyway, when I get the new back box built, I'll be looking for an sound level output within reasonable levels, in respect of an OE exhaust which, I'm sure can't be exactly quiet due to only having 1 silencer ?!

If the theory serves me right, it should automatically be quieter than what I have now, just because the pipe is that much longer. With the addition of the silenced decat pipe and the larger rear silencer, it should be quieter than a standard car !

 

[youngsyp]

The plot thickens with regard to my number plates !

I went to an MOT place yesterday and they refused to stamp my defect notice as, they "couldn't read them from 20 metres away". They then proceeded to lie to me and said they phoned VOSA and they told them this was the case and it didn't matter that the car was an import, it should have UK spec standard plates. This was despite me waving the legislation under their nose !

Needless to say, I called VOSA and they gave me the real story. Effectively, it doesn't matter what size your number plates are, or how large the characters are, as long as they have the correct spacings and there's nothing on the plate that could obscure any character, they'll pass an MOT.

All explained here: http://www.ukmot.com/6-8.asp

It astonishes me that all these agencies, VOSA, the DVLA etc... don't sing from the same hymn sheet and even more that the staff at this MOT station, clearly don't know what they're doing !

 

[stevepudney]

Sounds promising, well done

So whats next

Steve

 

[youngsyp]

Sounds promising, well done

So whats next

Steve

Well, after an hour at the MOT place again yesterday, they finally agreed that both my plates were fully legal, whether that be by MOT standards, DVLA standards or any other standards (they were out there with a tape measure and everything) ! I didn't want to tell them "I told you so !". Needless to say, I'll be keeping the MOT bible document, statutory document and the DVLA standards document in my glovebox from now on !

As for what's next..... I'm off to CC Customs in Wellingborough, on Friday to have a silenced decat and new rear silencer fabricated. Whilst I'm there, I'm going to enquire about a manifold and steel intake pipe.
If it's not dark when I get back, I'll be going to the police station to get this guys approval on the new exhaust. If it is dark, I'll be going up there on Saturday. After he's approved it, I'll be informing him that I intend to send a formal written complaint to his superintendent, as I don't think he handled the situation very well, over stepped his responsibilty, gave me the wrong information and no clear criteria for what noise levels I had to abide by. Coupled with unrealistic expectations, as he didn't know what car he was dealing with !

Hopefully, that will be the whole sorry mess over and done with !

Cheers

Paul

 

[youngsyp]

Did a small experiment this morning. I broke my SPL meter out and measured the sound output of the exhaust at idle (around 925 rpm) and it was 83 db (A) at about 0.5 metres. Now, if my understanding of sound pressure level is correct, in order for my exhaust to be illegal, according to that legislation I found, I.e. over 101 db (A) at 0.5 metres, it would need to be 18 db (A) louder at 3/4 maximum engine speed. As spl measurement is logarythmic (every 3 db is twice as loud), that's 64 times as loud ! I can't see that being the case ?!

 

[marc]

I dont quite get what you posted ?

The legislation states that a car with a noise level of over 101db at 3/4 throttle would fail?

I think if its reading 81db on tic over then surely it would raise by 18db when your on 3/4 throttle? Also I wouldnt imagine it would be 64 times louder on 3/4 throttle that would be a bit too loud, lol

As I said I didnt quite get what you posted.

 

[youngsyp]

I dont quite get what you posted ?

The legislation states that a car with a noise level of over 101db at 3/4 throttle would fail?

I think if its reading 81db on tic over then surely it would raise by 18db when your on 3/4 throttle? Also I wouldnt imagine it would be 64 times louder on 3/4 throttle that would be a bit too loud, lol

As I said I didnt quite get what you posted.

A rise in volume of 18 db is the equivalent of the sound getting 64 times louder. What I'm trying to get at is that I can't quite see how my exhaust could be 64 times louder at 3/4 maximum engine speed, as it is at idle. It sounds like that would be extremely loud but, 101 db isn't that loud in reality.
I think I need to do some more testing !