Noise limits

There seems to be a lot of post on here regarding noise limits and how they're measured ect. I got this email from Focussed Events and thought others might find it helpful/interesting.

Quote:

Circuits and the limits:
Donington Park 98db and 105 db measured as a drive by with multiple meters at trackside.

Silverstone 102db drive by meters at circuit (customers are photographed on the national straight as they trigger the meter )but 105 measures at ¾ rev on a static test.

Brands Hatch 105db (ACU) and 92db drive by.

Brands Hatch Eves 102db (ACU) and 92db drive by.

Brands Hatch GP 101db (ACU) and 92db drive by.

Cadwell Park 105db (ACU) and 92db drive-by (day and eve).

Oulton Park 102db (ACU) and 89db drive by.

Snetterton 102db (ACU) and 92db drive by(same for eve).

Bedford 101db (ACU) and 87.5db drive by.
Statics are all measured as per ACU regulation.
All drive-bys meters are at 20 metres from the edge of the track.

Mallory Park 105db during the weekdays and Tuesday to Friday.
Saturdays and Sundays are 98db for Trackdays, these are all measured as a static by the ACU handbook .

Anglesey 105db measured as a static as per the ACU test.

Pembury 102 static test as per the ACU handbook.

The ACU measurement:
400cc 4 cylinders 8000rpm
600cc 4 cylinders 7000rpm
600cc 3 cylinders 6500rpm
750cc 4 cylinders 7000rpm
750 cc 2 cylinders 5500rpm
Over 750cc 4 cylinders 5500rpm
Over 750 2 cylinders 5000rpm
These should be measured at 45 degrees with the meter 500mm from the end of the can.

So If you had a look through all of that and I didn't bore you too much....here are the problems!

Where the confusion lies

Silverstone measures Its own way, not as per the ACU. Its ¾ rev at the 500mm (no matter what the engine size).

Donington 98db events are now required to have only road silencers or baffles fitted, but heres the problem that customers have.......they pass on a 92 drive by at MSV circuits but these are measured 20 metres back from the track, where the Donington measurement Is taken trackside. So where we have the confusion Is when customers see the 92db drive-by at an MSV circuit and think they will pass at Donington, which they wont.

So I hope thats all helps.

Where are we now?

Unfortunately I really don't think we will get a uniform way of measurement which as far as I am concerned Is very disappointing for you the customers, and believe me I have badgered away at this for a few years.
Regarding the compliance.

Well you all love what you do, so I know we will go with It, and to be fair Its not really the limits that have altered drastically, Its only been 1 or 2 db here and there, whats causing the Issues Is that the policing Is more definite.
So Is that a bad thing?

Well If we don't work with the problem and take a responsible approach then yes It will be, because everyone will end up on road systems! and remember how expensive they are to replace.

Here's an Interesting point..... all trackdays at Misano (Italy) are on road systems only.

I was at Donington on Monday to help with the 1st day of the new regulation. I explained the new requirement and everyone was nodding and In agreement. I checked the groups and found 4 problem bikes In group 1, 1 In 2 and none In 3, and then 2 In group 4. All these riders happily went off and fitted the baffle....it was only £25, you lose about 3 HP and you take It out for a noisier event. But after the sighting laps I noticed a rider trying to slip out, and no baffle!

So whats more Important, the £25 and a baffle he can use.....or the closure of a circuit!

I have to be honest, the day really was quieter.

And less stress. Customers where happy, as they were not getting black flagged and pulled In, so they were just riding and enjoying their day and the circuit staff where happy as everything was within the limit.

I think everyone Is starting to understand the problem, I wish It wasn't as confusing ( and hopefully the above Information will help). So lets work together as riders, tdo's and circuits to keep these boring and persistant protesters from winning their war!

Thruxton/Croft and Castle Combe have enough problems, we don't want anymore circuits joining them.

Please remember

Noise meters are regularly calibrated and you will need to work with the staff at the circuits using them, but remember that an aggressive challenge will never help your case and Its always better to work with them, you will find that they are always willing to help and try to get you sorted and on track.

Aftermarket cans

They need to be repacked on a regular basis, as the packing blows out and then you are too noisy.

Don't always believe what the box says.....how did they measure the system, remember all the different ways that circuits measure and the manufacturer wants to sell his product.

If you can, on a day with a stricter limit, bring your road can with you.

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