Car Exhaust Noise

[AAGR]

Recent BMW M3s have four exhaust pipe outlets coming out of the rear bumper/moulding. What would the police make of that ?

[simoid]

AAGR said:

Recent BMW M3s have four exhaust pipe outlets coming out of the rear bumper/moulding. What would the police make of that ?

Probably "that car's going a bit fast."

[Stinkfoot]

Got a pull just after I had a full Evolve system with headers fitted to the M5. The copper just wanted to see if the exhaust had only one box on it "like the Skylines".
When he saw that the car still had 6 boxes on it he was happy. He then said that it sounded fantastic and we had a good car chat for 10 mins or so. I think a good attitude is half the battle to be honest when it comes to speaking with the bib.

The offending exhaust.

[Marcellus]

Stinkfoot said:

Got a pull just after I had a full Evolve system with headers fitted to the M5. The copper just wanted to see if the exhaust had only one box on it "like the Skylines".
When he saw that the car still had 6 boxes on it he was happy. He then said that it sounded fantastic and we had a good car chat for 10 mins or so. I think a good attitude is half the battle to be honest when it comes to speaking with the bib.

six boxes? I know I've got four how have BM squeezed in 6 and what's the advantage?

[Stinkfoot]

Marcellus said:

six boxes? I know I've got four how have BM squeezed in 6 and what's the advantage?

Best way to describe it although with the cats you could say its 8 boxes !

http://bmwfans.info/parts/catalog/E39/Sedan/Europe...

[TinyCappo]

Marcellus said:

Stinkfoot said:

Got a pull just after I had a full Evolve system with headers fitted to the M5. The copper just wanted to see if the exhaust had only one box on it "like the Skylines".
When he saw that the car still had 6 boxes on it he was happy. He then said that it sounded fantastic and we had a good car chat for 10 mins or so. I think a good attitude is half the battle to be honest when it comes to speaking with the bib.

six boxes? I know I've got four how have BM squeezed in 6 and what's the advantage?

backpressure. pretty much all BMWs are really finely tuned on backpressure probably needs 6 to keep it sweet/not flat.

[rlw]

Could someone please explain to me how this "law" about noise might be applied to a twenties or thirties Bentley with a fking great big engine and no silencer boxes worthy of the name. This whole thing just seems so fking unreal and stupid. My (ex) GT3 easily made 100dB at 4000rpm and went much louder at higher revs but was completely standard.

[SarGara]

I assume its more a case of "if you don't pass the attitude test" that it is enforced?

[Monkey boy 1]

rlw said:

Could someone please explain to me how this "law" about noise might be applied to a twenties or thirties Bentley with a fking great big engine and no silencer boxes worthy of the name. This whole thing just seems so fking unreal and stupid. My (ex) GT3 easily made 100dB at 4000rpm and went much louder at higher revs but was completely standard.

The law was introduces in 1986 and relates to vehicles used on or after 1/10/83. so a 1920's Bentley would be OK.

anyway, After a long wait I have drop on my doorstep a court summons for Feb 2013 about "Using a vehicle with an exhaust system that has been modifies as to increase the noise made by the escape of exhaust gases"

My issue now is that, Yes I know that the exhaust is a modified exhaust and, Yes it is louder than a standard OEM system, but it still does not prove that the system is illegal as the Police check was done incorrectly and not in accordance to ISO5130.

Edited by Monkey boy 1 on Saturday 12th January 19:12

[s p a c e m a n]

Monkey boy 1 said:

anyway, After a long wait I have drop on my doorstep a court summons for Feb 2013 about "Using a vehicle with an exhaust system that has been modifies as to increase the noise made by the escape of exhaust gases"

Where do they have proof of that from, did they inspect your exhaust to show that it is not standard? A db test is hardly proof that you do not have a complete 'e marked' exhaust on your car, or that it differs from standard.

[simoid]

s p a c e m a n said:

Monkey boy 1 said:

anyway, After a long wait I have drop on my doorstep a court summons for Feb 2013 about "Using a vehicle with an exhaust system that has been modifies as to increase the noise made by the escape of exhaust gases"

Where do they have proof of that from, did they inspect your exhaust to show that it is not standard? A db test is hardly proof that you do not have a complete 'e marked' exhaust on your car, or that it differs from standard.

That'll be fun in court.

"Officer, can you identify which of these cars has a standard exhaust?"

* pictures of some exhausts followed by blank looks *

"Thought not, I'll be off now."

[liner33]

Monkey boy 1 said:

The law was introduces in 1986 and relates to vehicles used on or after 1/10/83. so a 1920's Bentley would be OK.

anyway, After a long wait I have drop on my doorstep a court summons for Feb 2013 about "Using a vehicle with an exhaust system that has been modifies as to increase the noise made by the escape of exhaust gases"

My issue now is that, Yes I know that the exhaust is a modified exhaust and, Yes it is louder than a standard OEM system, but it still does not prove that the system is illegal as the Police check was done incorrectly and not in accordance to ISO5130.

Edited by Monkey boy 1 on Saturday 12th January 19:12

How has your exhaust been modified to increase noise??

[Monkey boy 1]

liner33 said:

How has your exhaust been modified to increase noise??

The exhaust is non standard,twin, twin tail pipes (ie. two each side as with the photo a few posts back), so as far as the BiB are concerned it's modified.

[streaky]

The exhaust system has been modified from that originally fitted. The replacement is not to the same design as the original.

Streaky

[simoid]

streaky said:

The exhaust system has been modified from that originally fitted. The replacement is not to the same design as the original.

Streaky

Modified to be noisier?

[s p a c e m a n]

So what they have done is realised from your correspondence that they have screwed up and can't make the original charge stick and changed it to 'using a modified exhaust' of which they have no actual evidence of, unless they inspected it or took photos?

I do wonder sometimes where the trafpol get such a bad reputation from.

[Baron Greenback]

"Awesome toyota turbo sound

http://www.youtube.com/watch?v=ieJUP9O9RG8" this must be legal for comedy reason just no near I live please!

[Durzel]

simoid said:

Modified to be noisier?

You're dwelling on semantics I think. Modified in the context of the law doesn't mean that the exhaust has been specifically engineered to make more noise, but that the exhaust system has been modified (from OEM) and also happens to produce increased noise.

My reading of it is that if you fit an aftermarket exhaust that doesn't produce more noise than the factory one you'd be fine (so long as it was E-marked otherwise there's a risk of a C&U offence I think?), but if you fit an aftermarket exhaust that produced more noise than the OEM - which let's face it practically all of them do as a byproduct of being designed to be more free-flowing - then you're bang to rights.

I also think it's one of those offences that is prosecuted in the absence of anything else being wrong. I've had a pretty loud exhaust on my car for years and never been pulled or prosecuted for it, but I do make a point of not blasting around residential/populated places drawing attention to myself.

[liner33]

Durzel said:

You're dwelling on semantics I think. Modified in the context of the law doesn't mean that the exhaust has been specifically engineered to make more noise, but that the exhaust system has been modified (from OEM) and also happens to produce increased noise.

My reading of it is that if you fit an aftermarket exhaust that doesn't produce more noise than the factory one you'd be fine (so long as it was E-marked otherwise there's a risk of a C&U offence I think?), but if you fit an aftermarket exhaust that produced more noise than the OEM - which let's face it practically all of them do as a byproduct of being designed to be more free-flowing - then you're bang to rights.

I also think it's one of those offences that is prosecuted in the absence of anything else being wrong. I've had a pretty loud exhaust on my car for years and never been pulled or prosecuted for it, but I do make a point of not blasting around residential/populated places drawing attention to myself.

Thats not my reading of it , more like the legislation was to address people who deliberately put holes in their exhaust or added things like cherry bombs or the whistles you used to be able to buy

Big difference between that and modifying an engine for more power by fitting an exhaust that makes more noise than stock

Also OEM exhausts are not always available nor are e marked pattern ones and ive yet to see and exhaust that states the DB expected from it.

[simoid]

Durzel said:

simoid said:

Modified to be noisier?

You're dwelling on semantics I think. Modified in the context of the law doesn't mean that the exhaust has been specifically engineered to make more noise, but that the exhaust system has been modified (from OEM) and also happens to produce increased noise.

My reading of it is that if you fit an aftermarket exhaust that doesn't produce more noise than the factory one you'd be fine (so long as it was E-marked otherwise there's a risk of a C&U offence I think?), but if you fit an aftermarket exhaust that produced more noise than the OEM - which let's face it practically all of them do as a byproduct of being designed to be more free-flowing - then you're bang to rights.

I also think it's one of those offences that is prosecuted in the absence of anything else being wrong. I've had a pretty loud exhaust on my car for years and never been pulled or prosecuted for it, but I do make a point of not blasting around residential/populated places drawing attention to myself.

Semantics?

He's being prosecuted for the modified exhaust "as to increase noise".