Phillis Posted January 19, 2011 Share Posted January 19, 2011 I got pulled over by vosa, for having a straight through exhaust, and he was not so happy , i got to replace one or both of my silencers, but i asked him if it was ok just to replace one, and he was happy enough long as it makes it quieter, so would replacing the end pipe with one with a backbox make it quiter enough to make them happy? got 10days to get it mot`d or i cant drive it. Quote Link to comment Share on other sites More sharing options...
disco_al Posted January 19, 2011 Share Posted January 19, 2011 did they do the official sound meter check? ISO 5130 Vehicle Noise MeasurementsISO 5130:2007 requires three consecutive measurements to ensure repeatability. These measurements are taken at a specified engine speed, or RPM, and the maximum sound level produced during the test is taken. Once three valid measurements have been made, the highest is taken and used as the valid result. The microphone can be placed at the specified measurement position, typically 45 degress and 0.5m from the exhaust of the vehicle under test. The CK:261S Measurement Kit includes a positioning template which can be used to ensure that the microphone capsule is set at the correct angle and distance from the vehicle exhaust. The tripod included with the kit allows the sound level meter and microphone to be set at the correct height from the ground. The remote control allows the user to control the measurements whilst ensuring that the engine is at the correct RPM for the test. The CR:261S can be supplied with a range of accessories and optional extras that allow the instrument to be used for various different applications. that's the standard test for motorsport noise, although i would imagine that being ISO it would apply to road vehicles as well. IVA states; Using sound level meter to the manufacturer’s instructions, carry out a stationary noise check. Which must not exceed 99dbA (it used to be 101 for the SVA) Position the vehicle within the authorised test area. With the sound meter horizontal, set the microphone height so that it is at the height of the exhaust outlet or 200mm from the ground, whichever is higher. a. At an angle of 45 degrees to the exhaust outlet in the direction which gives the greatest distance between it and the vehicle contour b. At a distance of 500mm from the exhaust outlet. With the vehicle at normal operating temperature, run the engine at 3/4 of its ‘maximum power’ speed, and note the sound level reading obtained. Note 1: Manufacturers drain holes are permitted in silencers Note 2: The exhaust may have several outlets up to 300mm apart connected to the same silencer. In this instance the microphone must face the outlet closest to the vehicle contour or highest from the ground. In all other cases, separate measurements must be taken for each exhaust outlet; the highest value obtained is the test value. Note 3: Where the engine maximum power speed is not available, the test may be carried out at 2/3 of engine maximum design speed. if they did, ask for the calibration certificate that would have been issued that morning before the equipment was given out for use. Quote Link to comment Share on other sites More sharing options...
Phillis Posted January 19, 2011 Author Share Posted January 19, 2011 Nope they didnt do a sound check, but as one of my wipers dusnt work, and i dont have a horn, i didnt want to get arsey but i might take it to a garage n get it sound checked Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 19, 2011 Share Posted January 19, 2011 What they said - no law against no silencers, and if they didn't do a proper sound level check then you can ignore them. dB meters are cheap from Maplins et al so you can measure for yourself to see if you're in the ballpark or on dodgy ground. Quote Link to comment Share on other sites More sharing options...
JJB Serenity Posted January 19, 2011 Share Posted January 19, 2011 It must be fairly noisy to have caught his attention though? Quote Link to comment Share on other sites More sharing options...
Guest Posted January 19, 2011 Share Posted January 19, 2011 I'm sorry, (well actually I'm not) if your land rover is not road worthy, i.e. no horn and the wipers not working properly and not wanting the VOSA man poking around it then it should not be on the road in the first place!! legalities around your exhaust sound like the least of your problems!! Quote Link to comment Share on other sites More sharing options...
Phillis Posted January 19, 2011 Author Share Posted January 19, 2011 It must be fairly noisy to have caught his attention though? Its not as loud as some of my mates cars, just when you set off, he followed me for ages, and said the only time it was really noisey was when i pulled out of a junction, and jason my wipers broke the other week just havent had time to fix them and i am not bothered them looking round it, read my original post, will a backbox make it queit enough? Quote Link to comment Share on other sites More sharing options...
JJB Serenity Posted January 19, 2011 Share Posted January 19, 2011 fair enough, I wasn't having a dig. Just wondered what had brought his attention to it in the first place. As people have said, he didn't test it so how does he know it's non-compliant with the regulations anyway. atb Quote Link to comment Share on other sites More sharing options...
Phillis Posted January 19, 2011 Author Share Posted January 19, 2011 i wasnt having a dig, just put quote so to show i was answering your question, its vosa for you there always right, but il get it sorted and put a backbox on, it is a little too loud for my liking just not got round to changing it. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 19, 2011 Share Posted January 19, 2011 Asking "will a backbox make it OK?" is impossible to answer. One type might, another might not. For all we know you have a 4" drainpipe from front to rear with leaking joints in between. I have a huge silencer on the 109 but it's still loud enough to rattle your fillings, and when I chopped the back-box off of Dad's V8 RR and it made absolutely no difference to the volume whatsoever. Quote Link to comment Share on other sites More sharing options...
JJB Serenity Posted January 19, 2011 Share Posted January 19, 2011 i wasnt having a dig, just put quote so to show i was answering your question, its vosa for you there always right, but il get it sorted and put a backbox on, it is a little too loud for my liking just not got round to changing it. Quote Link to comment Share on other sites More sharing options...
dirtydiesel Posted January 19, 2011 Share Posted January 19, 2011 There is no decibel meter used in the mot test the wording in the manual is open to interpritation Method of inspection; "with the engine running, assess subjectively the effectiveness of the silencer in reducing exhaust noise to a level considered average for the vehicle" Reason for rejection (ie a fail); "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 of a similar vehicle with a standard silencer in average condition" If you have a straight through exhaust and have uprated and tuned the engine to suit, the comparison would have to be to another tuned 90 with a straight through exhaust. I've discussed this many times with vosa (but in restpect to noisey chav'ed up corsa's and alike) and if the vehicle presenter can prove to me that engine has been modified, then as a tester i cannot fail it as i have nothing to make a comparison with. Quote Link to comment Share on other sites More sharing options...
will_warne Posted January 19, 2011 Share Posted January 19, 2011 Spot on, Dan. Phillis, you can ignore VOSA in this instance - they have no power to test noise at the roadside. However, use the time to sort the wipers and the horn as that is something you can be pulled for Out of interest, how long have you had the exhaust? I found that on a hard top an unsilenced system was just too noisy. Adding a straight through silencer won't harm power and will cut the noise level a little. There is no decibel meter used in the mot test the wording in the manual is open to interpritation Method of inspection; "with the engine running, assess subjectively the effectiveness of the silencer in reducing exhaust noise to a level considered average for the vehicle" Reason for rejection (ie a fail); "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 of a similar vehicle with a standard silencer in average condition" If you have a straight through exhaust and have uprated and tuned the engine to suit, the comparison would have to be to another tuned 90 with a straight through exhaust. I've discussed this many times with vosa (but in restpect to noisey chav'ed up corsa's and alike) and if the vehicle presenter can prove to me that engine has been modified, then as a tester i cannot fail it as i have nothing to make a comparison with. Quote Link to comment Share on other sites More sharing options...
Phillis Posted January 19, 2011 Author Share Posted January 19, 2011 erm, i removed the backbox a few weeks after my mot, which was last march, then last november i got a straight through middle pipe, as my middle box was gettin past its sell by date, but soon as i fitted it i didnt really like it just put up with it, think im just going to get a replacment pipe which includes the backbox, and hopefully it should be ok, rest of the exhaust is new. with a straight through it does give it a nice roar, but its a landrover not a ferrari so its not really needed is it.. Quote Link to comment Share on other sites More sharing options...
mickeyw Posted January 19, 2011 Share Posted January 19, 2011 Its not as loud as some of my mates cars, just when you set off, he followed me for ages, and said the only time it was really noisey was when i pulled out of a junction, I was of the understanding that the plod are not allowed to follow you for more than a short distance before stopping you. They either do or don't have a reason to stop you from the start, they shouldn't follow you in the hope that you might give them cause to stop you, that's called harrassment. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 19, 2011 Share Posted January 19, 2011 What engine is it? Quote Link to comment Share on other sites More sharing options...
KKMobile Posted January 19, 2011 Share Posted January 19, 2011 They do like to put the woolies up people!!! Few years back i bought a transit that had tinted side windows @ the front. got tugged & told there to dark remove them. When i replied have you got your light metre on you with certificate to check properly, he looked at me & replied it's not working at the moment but i'm telling you their to dark! Remove the tint or i'll nick you! My reply was your word against mine & you can't prove it so leave me alone. He then started looking at the tyres! being a mobile tyre service i replied, Have i got cnut on my head to which he laughed! said good point & i carried on with my day! Quote Link to comment Share on other sites More sharing options...
g&t Posted January 20, 2011 Share Posted January 20, 2011 I have a huge silencer on the 109 but it's still loud enough to rattle your fillings, and when I chopped the back-box off of Dad's V8 RR and it made absolutely no difference to the volume whatsoever. I've had the back box on two 3.5efi's drop off due to a combination of corrosion & LR's theory that the heavy 'box in question does not need any support In both cases the exhaust 'burble' was slightly more pronounced & the volume slightly louder, in fact I thought of asking an exhaust manuf. to produce a rear pipe w/o a box (you can't just fit a straight piece of pipe as it will foul the underside of the bumper) but never got around to it. Quote Link to comment Share on other sites More sharing options...
mickeyw Posted January 20, 2011 Share Posted January 20, 2011 I've had the back box on two 3.5efi's drop off due to a combination of corrosion & LR's theory that the heavy 'box in question does not need any support In both cases the exhaust 'burble' was slightly more pronounced & the volume slightly louder, in fact I thought of asking an exhaust manuf. to produce a rear pipe w/o a box (you can't just fit a straight piece of pipe as it will foul the underside of the bumper) but never got around to it. Losing a rear box may not make a huge difference in exhaust note. However its absence can make quite a difference in cabin noise due to the gases reverberating against the inside of the rear wing, which it is normally directed away from. Quote Link to comment Share on other sites More sharing options...
SiWhite Posted January 20, 2011 Share Posted January 20, 2011 I was of the understanding that the plod are not allowed to follow you for more than a short distance before stopping you. They either do or don't have a reason to stop you from the start, they shouldn't follow you in the hope that you might give them cause to stop you, that's called harrassment. Extraordinary statement. No such law exists, old chap. In respect of 'harassment' - how could you state that a car was following you and not just going the same way as you? Accusations of 'it's Police Harassment, innit' are very common and almost always unsubstantiated. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 20, 2011 Share Posted January 20, 2011 No such law exists, old chap. It's certainly in the rules for CCTV (Police/council etc.) operators, whether that's the law or just guideline I don't know. They can't follow you round on-camera for ages unless they have good reason. Otherwise a dispoportionate number of young ladies would find themselves under survillance, especially in summertime. They also can't look into your house front window etc., the cameras are/should be programmed so they can't be pointed that way, or the operator sees a blank/fuzzy square on the screen. So basically the job has the main perks removed they have to content themselves with catching criminals and "you've been framed" moments. Quote Link to comment Share on other sites More sharing options...
Ratty43 Posted January 20, 2011 Share Posted January 20, 2011 It's certainly in the rules for CCTV (Police/council etc.) operators, whether that's the law or just guideline I don't know. They can't follow you round on-camera for ages unless they have good reason. Otherwise a dispoportionate number of young ladies would find themselves under survillance, especially in summertime. A mate of mine used to deliver bread and he said a CCTV camera in St. Ives was always either pointing at a flat window or watching the sunrise. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 20, 2011 Share Posted January 20, 2011 A mate of mine used to deliver bread and he said a CCTV camera in St. Ives was always either pointing at a flat window or watching the sunrise. I didn't say all of them were set up properly it's dodgy ground as they do randomly take tapes away and audit them to check for that sort of thing, quick way to lose your job Quote Link to comment Share on other sites More sharing options...
mickeyw Posted January 20, 2011 Share Posted January 20, 2011 Extraordinary statement. No such law exists, old chap. In respect of 'harassment' - how could you state that a car was following you and not just going the same way as you? Accusations of 'it's Police Harassment, innit' are very common and almost always unsubstantiated. My comment stems from a case some years back, involving myself and a work mate. We were driving back to his house (approx a six mile trip) after work (his car, him driving) on a dark winter's evening to find a car right up our backside, pushing us along, like they do, so we sped up a little hoping the car behind would leave us a bit more room. As we neared our destination, and turned into his road, (a residential area,) we clocked that it was a police car following, and promptly got flashed to stop. The discussion that followed was along the lines of them having stopped us because we had been speeding. On asking quite where this had happened, a location was given close to where we had sped up to shake of the following car (which it turned out had been them). This location was at least 3-4 miles from where they stopped us. The business of producing one's papers followed, along with the old 'we'll let you off this time' as our names weren't on their list of habitual bad drivers. Later conversations with those in the legal profession brought to light the points I have mentioned above, and the thought that the police let us go because they were on shaky ground with what they were claiming, and where it alledgedly occurred in relation to where we were stopped. Just my experiences here I'm afraid. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted January 20, 2011 Share Posted January 20, 2011 As a side note, if someone is driving up your backside, don't introduce more energy into a potential collision, slow down slowly, right down.... then they either back off or overtake you, problem solved. Quote Link to comment Share on other sites More sharing options...
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