Loudness?

[jjmartin349571]

What is the road legal limit anyway?

I've spent hours researching this and the answer seems to vary quite a lot. For MOT purposes it's down to tester discretion within reason. There is an EU limit for production cars, and if you go by construction and use your car should conform to the figure that was valid when your car was produced. Truth is though an accurate decibel reading is near impossible without a suitably set up environment so if the police do pull you, I'd refuse the ticket and ask them to take you to court. They'd have a hard time arguing that their ears are accurate enough measuring devices to be proving that your car is indeed too loud.

That's what I've pulled together from my research, it may read crap as I'm rushing to type at work anyone who knows better please feel free to correct me also

[Merlin]

It was just out of curiosity I wondered what the road limit was. All I care about is that im under or over 105db .

I'd be interested to read the protocol for sound testing at the side of road for police. Distance from exhuast tip, rpm, etc.... How can they have a single protocal for all cars when a diesel revs comfortably to ~4-5K, and the Lude 7-8K

[lewd lude lover]

they cant. it all basically depends on weather you pass the 'kebab test'. this is administered within the first 45 seconds of meeting the police.

Measuring sound for PA has to be an average across the stage and from differing distances.

[jjmartin349571]

Yeah, when cars are tested for EU compliance it's done in a special sound testing area free from anything that could cause interaction with the exhaust noise from the car. iirc it's done at a distance back and to the side of the exhaust, with the decibel meter pointed at x degrees away from the exhaust tip. They take readings across the rev range. Long story short is the police can't do this so anything they try to pin on you will be very flimsy. Like LLL says, mainly they just pick up boy racers being absolute dicks and pissing everyone off. I've heard of people with properly built cars getting pulled though, a prodrive scooby and Golf G60 spring to mind, the drivers refused the penalties & took it to court where the cases were thrown out as the CPS deemed there was little chance of prosecution. In short even if your car is loud, considerate driving will probably make the police ignore you

[lewd lude lover]

^^^^^ yep. sounds good.

[jozefsan]

sound measurement its done on 2/3 of rew range, rew range is from 0- red line start

you cant be louder then factory dB on factory fitted exhaust system, but if they find even one part not match to factory part it mean your car have modified exhaust and you drop in 85 dB limit and fail dB test.

[macky_6]

I measured my SiR at 99dB. And you know how loud that was

I also measured the old white Civic at Knockhill last year and even that was only 102dB. No way you will be louder than that

[jozefsan]

I measured my SiR at 99dB. And you know how loud that was

I also measured the old white Civic at Knockhill last year and even that was only 102dB. No way you will be louder than that

i have ticket for 106 dB

[littlefeller]

so let me get this strainght, if i were to build my own can including engine, it could be as loud as i like as it was produced that way doesnt seen quite right to me

[jjmartin349571]

No, kit cars have to be approved within limits too, however they are more lax than the limits mass produced cars have to be built to.

The noise limit for your car comes down to applying the construction and use regs against the fact all cars are built to European noise limits. However, practically, the police cannot produce accurate enough noise level readings at the roadside, so you shouldn't really accept a ticket from them. I wouldn't, I'd request they took me to court To argue their case with their 'evidence'