Car Exhaust Noise

[bigdavy]

Well done op, a result of sorts.

I'm just wondering if your squirming police officers will have learned anything or will now be looking out for you to stop again and next time ensure their paperwork is 100%

Seems a huge grey area, coming down to a magistrates opinion if you have the balls to take it that far.

[Slidingpillar]

Not really relevant as my vintage car was made in 1930, but when I checked the noise before fitting non original and quieter exhausts I got 113dBA at what was meant to be 2/3 max revs (no rev counter) at 1/2 metre at 45 degrees. Oh and that was one exhaust pipe - it's got two the same...

The new silencers that I may yet replace for being too big and obvious are quieter, but still noisy - I had to stop 100yds from a horse and switch off as I was scaring it.

An owner of a similar car was done for noise in the 1930s, and he too got off.

[herewego]

Monkey boy 1 said:

Exhaust noise ticket is a non-endorsable £30 FPN. They can't issue a vehicle rectification notice because it is not an MOT failure as sound levels are not a requirement for an MOT.

To me this is just one of the many new laws & regs that the beaurocrats have brought out without thoroughly checking over it to see if it actually legal to administer it.

It isn't really a new law, it goes back to 1986.
Will you do anything about the exhaust or just hope you don't bump into the same police officer again?

[sean x]

Great read.
Looks like I'll be getting (or making) a set of these http://www.quicktimeperformance.com/QTEC/ in that case!

[Retroman]

The fine wording of the law says it's illegal to modify an exhaust system for it to make more noise, but one could perhaps argue that doesn't include removing the exhaust system and replacing with a full aftermarket system. That way the system hasn't been "modified" to create more noise, but has been replaced with an alternative which creates more noise as standard.

I'm not sure why the comments about the noise not being part of the MOT test either. It's an MOT fail if the noise produced by the exhaust is louder than what would be expected from a standard exhaust system in good working condition. It's been that way for years, but not all inspectors adhere to it

[Monkey boy 1]

Retroman said:

The fine wording of the law says it's illegal to modify an exhaust system for it to make more noise, but one could perhaps argue that doesn't include removing the exhaust system and replacing with a full aftermarket system. That way the system hasn't been "modified" to create more noise, but has been replaced with an alternative which creates more noise as standard.

I'm not sure why the comments about the noise not being part of the MOT test either. It's an MOT fail if the noise produced by the exhaust is louder than what would be expected from a standard exhaust system in good working condition. It's been that way for years, but not all inspectors adhere to it

Because the noise check is subjective at present, there are no requirements to use any measuring devices to measure noise at an MOT so it's down the the descression of the tester.

Also if you have replaced the exhaust system with a full aftermarket one you 'have' modified it from the original

[TonyRPH]

Monkey boy 1 said:

<snip>

Also if you have replaced the exhaust system with a full aftermarket one you 'have' modified it from the original

That's interesting and possibly open to interpretation.

Surely, if you go to a 'fast fit' outlet and fit an off the shelf exhaust, strictly speaking, it's not OEM and therefore not original, and could be interpreted as a modified exhaust?

How many 'pattern' exhaust systems are actually an *exact* replica of the original OEM system?

[herewego]

TonyRPH said:

Monkey boy 1 said:

<snip>

Also if you have replaced the exhaust system with a full aftermarket one you 'have' modified it from the original

That's interesting and possibly open to interpretation.

Surely, if you go to a 'fast fit' outlet and fit an off the shelf exhaust, strictly speaking, it's not OEM and therefore not original, and could be interpreted as a modified exhaust?

How many 'pattern' exhaust systems are actually an *exact* replica of the original OEM system?

I don't think he finished his sentence. I think he meant to say modified to make it louder than original. It isn't modification that's important, it's the noise level.

[NDA]

An interesting thread and one I've followed.

The result wasn't entirely satisfying. But I'm left feeling that the Police were over zealous - I wonder what this spurious charge cost to bring to court?

Also, several of my cars have had modified exhausts - in one case, modified by the factory who built the car to enhance HP.

[herewego]

Monkey boy 1 said:

Retroman said:

The fine wording of the law says it's illegal to modify an exhaust system for it to make more noise, but one could perhaps argue that doesn't include removing the exhaust system and replacing with a full aftermarket system. That way the system hasn't been "modified" to create more noise, but has been replaced with an alternative which creates more noise as standard.

I'm not sure why the comments about the noise not being part of the MOT test either. It's an MOT fail if the noise produced by the exhaust is louder than what would be expected from a standard exhaust system in good working condition. It's been that way for years, but not all inspectors adhere to it

Because the noise check is subjective at present, there are no requirements to use any measuring devices to measure noise at an MOT so it's down the the descression of the tester.

Also if you have replaced the exhaust system with a full aftermarket one you 'have' modified it from the original

MOT inspectors make subjective decisions all the time, e.g. ball joint wear, so they can make a judgement about exhaust noise. However the MOT test is primarily a safety check and while a broken exhaust is a safety issue, a modified one is mostly not. I'm just guessing that MOT inspectors are less interested in non safety issues.

I still don't understand why the police couldn't just give you a rectification notice though. What would they do if you failed to rectify it?

Maybe you can get the exhaust manufacturer to modify it to a legal noise level.

[Johnnytheboy]

Exactly - if I'd wanted to, my Focus could have been fitted with a louder Mountune exhaust by my dealer, either from new or later.

Is one legal and the other not?

Daft.

[herewego]

Johnnytheboy said:

Exactly - if I'd wanted to, my Focus could have been fitted with a louder Mountune exhaust by my dealer, either from new or later.

Is one legal and the other not?

Daft.

It could be that the test value for that car is below the legal minimum of 74 for the drive by type approval test in which case the Mountune exhaust could be louder but still within 74. A pedant could argue that it's louder than original, but in practice no one's is going to prosecute that. It could also have different frequencies that make it sound more powerful, but still within the 74. It may also be possible that the sound is somehow made louder inside the car for the benefit or otherwise of the driver, but no more so outside. Don't ask me how that's done but I've seen it claimed.

[Cotty]

My new stainless exhaust is louder than standard but it passed the MOT

[AstonZagato]

£30FPN? No points? Not really going to deter anyone from putting a Larini system on their Ferrari F12.

[Retroman]

Cotty said:

My new stainless exhaust is louder than standard but it passed the MOT

Most cars with aftermarket exhausts do, but they shouldn't.

[Cotty]

Retroman said:

Cotty said:

My new stainless exhaust is louder than standard but it passed the MOT

Most cars with aftermarket exhausts do, but they shouldn't.

Why shoudn't they pass?

[Retroman]

Here's the exact quote from the MOT manual for reason to fail.

"4. 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 standard silencer in average condition."

[Cotty]

Retroman said:

Here's the exact quote from the MOT manual for reason to fail.

"4. 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 standard silencer in average condition."

Ok let me check the volume to see if its ok. Whats the standard silencer in average condition's volume? Which makes that wording complete horse crap.

Or what if its above, but not unreasonably above then it passes.

[Grenoble]

And clearly allows it to be above the standard.

[V8RX7]

Cotty said:

Retroman said:

Here's the exact quote from the MOT manual for reason to fail.

"4. 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 standard silencer in average condition."

Ok let me check the volume to see if its ok. Whats the standard silencer in average condition's volume? Which makes that wording complete horse crap.

Or what if its above, but not unreasonably above then it passes.

I'll agree on say a TVR (which is quite rare and loud as std) it may be hard to judge.

But on a standard Corsa, Saxo etc a standard one is virtually silent and some of the 3" exhausts can be heard streets away so it would be obvious to my Mum let alone an MOT inspector.

I have owned many loud cars and only had a tiny issue once - I was stopped in my Manta for suspected speeding and he asked me to start it and rev it. I did

he said "I think that's too loud "
(It had a 2.5" straight through system on it)

I said "There isn't a noise limit for cars only bikes"

"Well I think it's excessively noisy"

"I don't - it's subjective isn't it"

He let it drop at that point.

Just got a producer as he couldn't prove my speed either - ah the good old days

Edited by V8RX7 on Thursday 30th May 19:34