IVA noise regulations

[lowdrag]

I downloaded the regs a while back, but nowhere can I seem to find, neither in the document nor on the internet, the actual specific Dba levels. It talks about "compliance with the required standard for noise" but this standard is not specified. I assume them to be 98db, but if anyone has the definitive answer I'd be grateful.

[2slo]

It's 99db. Regs are here under noise: https://online.businesslink.gov.uk/Transport_files...

[lowdrag]

Thanks for that, but I've also read that there is a margin of 2db. Is the 99db including the margin?

[2slo]

Margin? I've never heard of that. My understanding is the car tested either meets the noise requirement or fails. Maybe certain test stations and some Inspectors are more lenient? I have heard of several cars being taken away with a complete rethink needed on silencer options before being re presented for test.
An easy check would be to take the vehicle in question to a race track, most of which, I believe will carry out a similar if not identical sound check for free (on the basis of the car getting on said track). My nearest circuit, Croft, certainly offers this service free. You could therefore potentially avoid a re test.

[lowdrag]

"The measured sound level must be no more than 2 dbA above the evidence supplied" That's what it states in the IVA document I have here, which is why I asked. frankly, the whole document is so opaque that I can't make much sense out of it at all. It also states:-

"A vehicle with permitted modifications must be accompanied by a stationary noise test report", which I assume to mean the evidence as above. For the rest, I can only find details of the distance from the exhaust and the positioning of the meter, but nowhere the actual level allowed.

[2slo]

Have a read through the document I posted the link to above. That, AFAIK, is the latest official regs for IVA. 99 db max, no margin mentioned.