Maximum legal exhaust noise in classic car?
Discussion
Years ago, I did speak to a couple of noise testers about this. Prosecution is very difficult for older cars, and if you are not creating a nuisance, at that time unheard of.
I was driving - and they knew as I turned up in it, a '1600' Morgan with twin delortos, a racing camshaft and all the other bits, that would imply. It struggled to get lower than 113dBA at 1/2 metre, 2/3rd max revs (the then hillclimb limit). In later years, I had to fit a longer exhaust to pass MSA limits, but there was a cost in bhp terms.
With that car, in Glasgow I passed a policeman doing a Golf driver for an obviously holed back box - I was considerably noisier, but quite legal. To say the driver was a bit fed up is an understatement, but other than the exit, there were no holes in my exhaust.
I was driving - and they knew as I turned up in it, a '1600' Morgan with twin delortos, a racing camshaft and all the other bits, that would imply. It struggled to get lower than 113dBA at 1/2 metre, 2/3rd max revs (the then hillclimb limit). In later years, I had to fit a longer exhaust to pass MSA limits, but there was a cost in bhp terms.
With that car, in Glasgow I passed a policeman doing a Golf driver for an obviously holed back box - I was considerably noisier, but quite legal. To say the driver was a bit fed up is an understatement, but other than the exit, there were no holes in my exhaust.
RoverP6B said:
Right... so how do the likes of Milltek, Akrapovic etc manage to trade?
They're not illegal to make or sell.Although a lot of aftermarket exhausts are illegal, it's not the easiest thing to be prosecuted for in court. Someone on here managed to get it thrown out a few years ago IIRC.
TheEnd said:
I'm sure the line was something along the lines of not being allowed to "modify an exhaust to make it louder", so drilling holes in the backbox, cutting out baffles etc are bad, but performance modifications are OK.
I'm pretty sure the legislation was aimed at all vehicle exhaust system modifiers not just poor ones.55palfers said:
"Noise" is a very subjective issue.
Pitch / frequency is also important in how annoying a sound is.
A rich V8 basso profondo is nice, a 50cc scooter with a high pitched rasping whine is not yet they may both be emitting the same sound level.
Difficult one.
Pitch / frequency is also important in how annoying a sound is.
A rich V8 basso profondo is nice, a 50cc scooter with a high pitched rasping whine is not yet they may both be emitting the same sound level.
Difficult one.
And your average V8 blipper does not also feel the need to peep their piss poor kiddie car horn as they zip around town at 20mph and crash into each other as they try to talk to each other as they ride side by side up the road
herewego said:
TheEnd said:
I'm sure the line was something along the lines of not being allowed to "modify an exhaust to make it louder", so drilling holes in the backbox, cutting out baffles etc are bad, but performance modifications are OK.
I'm pretty sure the legislation was aimed at all vehicle exhaust system modifiers not just poor ones.GC8 said:
Its intention is clear from the syntax. You may not modify an exhaust to make it louder, meaning drill holes or remove silencers. This doesn't stop you from fitting a replacement exhaust which may be louder.
The after market exhaust would need to be E-marked to comply with construction and use regulations.Not many of them are.
This is also why the MOT has a part in it which says if the noise emitted from the exhaust system is clearly louder than standard it should be a fail.
Right. As it happens, I've been thinking of gutting the forward silencers on my 535i (which is a 1997-built example) to get a bit of noise back (fitting new cats rather killed the noise) and wondered where I might stand on it. I'd also like to turn my 520i into a cammy, revvy hot-rod wagon - again, might need to rethink that if the noise Nazis would deem it unacceptable. I've also long harboured a dream of owning a Jaguar XJ13 replica and wondered where that might stand - the original is mind-bogglingly loud (I think I read it's been measured at 136 decibels).
RoverP6B said:
Right. As it happens, I've been thinking of gutting the forward silencers on my 535i (which is a 1997-built example) to get a bit of noise back (fitting new cats rather killed the noise) and wondered where I might stand on it. I'd also like to turn my 520i into a cammy, revvy hot-rod wagon - again, might need to rethink that if the noise Nazis would deem it unacceptable. I've also long harboured a dream of owning a Jaguar XJ13 replica and wondered where that might stand - the original is mind-bogglingly loud (I think I read it's been measured at 136 decibels).
I was in the Sturgess showroom in Leicester in the mid 90s (having a look around while buying spares for my XJS as usual). They had a Lister E Type in to show off. It didn't have much in the way of exhaust pipes.I nearly wet myself when they started it up in a previously quiet showroom!
Gits!!
FF
GC8 said:
Its intention is clear from the syntax. You may not modify an exhaust to make it louder, meaning drill holes or remove silencers. This doesn't stop you from fitting a replacement exhaust which may be louder.
Modifying an exhaust would include a replacement system which is clearly louder than the original item. However, goodwill from the police and MOT testers means you can happily have a louder exhaust, without getting into the MOT fail/S.59 warning area for daft levels of noise.GC8 said:
herewego said:
TheEnd said:
I'm sure the line was something along the lines of not being allowed to "modify an exhaust to make it louder", so drilling holes in the backbox, cutting out baffles etc are bad, but performance modifications are OK.
I'm pretty sure the legislation was aimed at all vehicle exhaust system modifiers not just poor ones.I'm a member of numerous Facebook 'car enthusiasts groups' for want of a better description, and there seems to be absolutely no doubt that the police have suddenly started to take an interest in any cars that are louder than standard.
I've seen photos of recent tickets that have been dished out saying things like 'exhaust louder than standard' - £50 fixed penalty.
They have been going after everyone from the very loud Corsa with a massive fart-can exhaust through to the people who have fitted a sensible performance system from a reputable manufacturer such as Jetex/Janspeed.
I think the party might be over for fruity sounding exhausts
Having said that, if you don't drive round residential areas or town centres late at night, or don't drive like an idiot, then the chances are you will be fine.
I've seen photos of recent tickets that have been dished out saying things like 'exhaust louder than standard' - £50 fixed penalty.
They have been going after everyone from the very loud Corsa with a massive fart-can exhaust through to the people who have fitted a sensible performance system from a reputable manufacturer such as Jetex/Janspeed.
I think the party might be over for fruity sounding exhausts
Having said that, if you don't drive round residential areas or town centres late at night, or don't drive like an idiot, then the chances are you will be fine.
herewego said:
GC8 said:
herewego said:
TheEnd said:
I'm sure the line was something along the lines of not being allowed to "modify an exhaust to make it louder", so drilling holes in the backbox, cutting out baffles etc are bad, but performance modifications are OK.
I'm pretty sure the legislation was aimed at all vehicle exhaust system modifiers not just poor ones.Newer legislation plugs this gap, of course.
Gassing Station | Speed, Plod & the Law | Top of Page | What's New | My Stuff