Exhaust/Engine noise

[jeffsy]

Could one of our friends in blue advise what - if any - is the law regarding noise from engines/exhausts? I have recently had a conversation with one of your colleagues on the subject but couldnt get any exact guidance.

Also would a car fail its MOT if it had the exhaust silencer/baffles completely removed ie is noise covered by the MOT?

I would appreciate it

Thanks

[motorwise]

have a read through this

www.motuk.co.uk/manual/contents.htm

[eliminator]

I seem to recall that altering an exhaust system so that it makes more noise than standard is against construction and use regs.

There was a big fuss a year (or two?) back when one Scottish force began stopping Impreza's and stuffing a sound meater into the back of the exhaust. Anyone with the PPP upgrade got a fine. Not sure of the outcome of that, but seem to recall that that BiB were wrong in the application of the law; fitting a PPP upgrade was not actually illegal.

Your case - taking out the baffles - would seem to fit the charge.

[SamHH]

eliminator said:

I seem to recall that altering an exhaust system so that it makes more noise than standard is against construction and use regs.

If a vehicle doesn't comply with the construction and use regulations, is it an offence? If so, for who; the driver, the person who modified the car, the registered keeper, the owner?

Also, if you are correct about the constructions and use regs, why are after-market exhausts that are louder than the standard part or parts allowed?

[tvrgit]

There is no noise measurement in the MOT for cars (There is a DbA limit for bikes but not cars)

I don't think that there is a definitive noise limit in C&U either - so it's difficult to see how prosecutions based on sound meter readings could be "sound".

I might be wrong about this, but as I understand it, the police can still decide that your car is "excessively noisy", without any measurement at all, or any limit to base that on. It seems to be entirely up to an individual officer.

[BO55 VXR]

AFAIK, the only offence you could be had up for is "unsociable behaveour" where you sit outside and rev your engine to the annoyance of the local (and sometimes, no so local) residents.

In which case, expect to receive an ASBO..... but first you have to define unsociable behaveour on a loud car

[daniboy]

Louder the better, i cant get MOT, with cats off.

[BO55 VXR]

daniboy said:

Louder the better, i cant get MOT, with cats off.

But that will emmissions, not noise

[eliminator]

That was the question raised to the Scottish BiB. They were taking the view that fitting an after market silencer that was louder than the original was a breach of C&U. I think that someone eventually stood up to the charge and asked for a court date. Assistance was sought from ProDrive - If Scottish BiB were correct then ProDrive had been selling / fitting illigal modifications and the whole after-market silencer industry was in trouble. The contrary interpretation of "adapting or modifying the exhaust system" was that there is no "adaptation or modification" if you fit EU approved elements.

Hence, no problem for EU stamped, road legal cans. Drill-out your own baffles and you are in for a fine.

I think this was covered in detail on Scoobynet (I had PPP on my last STi, so had an interest).

[anonymous-user]

The only noise tests are carried out for EU type aproval, once this is passed a vehicle may have it's silencer changed to an aftermarket item post registration. That is why the PPP equipped Impreza has to be registered prior to fitting of the PPP equipment. Incedentally there is a function in the Impreza ECU stock mapping that will limit boost to 0.6BAR if you hold a constant throttle and speed at 50Km/hr for 3 seconds then go full throttle, this is to allow the car to limit it's power (and therefor noise) for the driveby type aproval noise test.

The basics are you are not allowed to remove the baffles from an exhisting system, but you can fit a new untampered with system that is louder than the original item.

[jeffsy]

Soooo..loud replacement engine OK (as long as I dont excessively rev it and get and ASBO), taking out the baffles is a no-no, after market replacement OK....therefore cherry bombs it is then!!

Thanks guys - anyone else got anything else on this for me??

cheers

[fangio]

Just your ASB attitude!

Manufacturers spend millions making cars comfortable and acceptable, then dickheads fit baked bean tins and think they sound great.........

If you read the link above to the testers' hand book, it says a car should sound as near to manufacturers' specs. as can be.

Edited by fangio on Sunday 7th January 17:57

[daniboy]

fangio said:

Just your ASB attitude!

then dickheads fit baked bean tins and think they sound great........

Edited by fangio on Sunday 7th January 17:57

I AM A DICKHEAD coz mine sounds great on my Scoob. (hks hyper)

[negative creep]

to be honest, I tihnk there should be regulations. Over loud exhasuts are quite frankly a pain, especially late at night when you want to get to sleep but some tosser will rattle your windows with his Jap cannon. One of my mates had a 4inch striaght through on his Impreza, was just stupidly loud, you ould hear him coming from a mile off. Was acceptable as I only saw him at work, but if I'd have lived anywhere near I would've been having a few words. Im not saying you shouldn't be allowed to fit louder exhasuts, but there should be a limit, it is just unfair on everyone else

[daniboy]

Mines 5inch straight through, didnt have 6inch in stock, My neighbours complain. (damn Busy bodies)

regulations, rules, laws i say riot.

Edited by daniboy on Sunday 7th January 19:21

[TheKeyboardDemon]

I would rather have a very quiet high performance car than a very noisy 1.2 litre little boys racers car with baked bean cans to make it sound like it's got grunt but crawls away from the lights while I quietly cruise away in front.

[shuvitupya]

If anyone down my road dares to drive a noisy car, they will get a brick through their windscreen.

[daniboy]

where u live

[guru_1071]

years ago i got pulled by the police in my mini for making 'excessive mechanical noise' - got a 7 day wonder for it.

i did try to explain to the guy that it was 2000 quids worth of straight cut gearbox sat on a 970 cooper s engine - to no avail.

i finally took all the noisy stuff of after my mother pointed out she could here me from about 3 miles away.....

[cooperman]

Why would anyone want a noisy car? The answer is 'they sound good'. But to whom do they sound good. Certainly not to me or many others. The person with the noisy car will probably comnplain if his neighbour plays loud music of a type he doesn't like late at night with his house windows open. Where is the difference? Noisy exhaust have no measurable effect on the road performance. Competition cars have noisy exhausts to gain that very last ounce of power which knocks a few tenths of a second off the lap time.
We have a young guy in our village who drives around with numbers on his doors and a loud exhaust. Does he think he's a rally driver? Clearly he's not or he would fail the strict noise test at the start. As guru1071 says, the straight cut gearbox on my rally Mini is noisier than the exhaust, but at least it's a genuine competition car.
Nothing is more 'chav' than a huge big-bore exhaust and a noisy stereo on a car driven with the windows open when that is done just to 'pose'.
Nick the lot of them if their exhausts are too noisy, so long as the actual noise levels are measured against a stated maximum lever at certain rpm figures.