Castle Combe noise

[edb49]

Trying to find out what the noise limits are.

Is it 100dB at 4.5k rpm or 3/4 of max revs? I've seen both mentioned.

Is there any driveby noise limit too?

[LordGrover]

4.5k, no drive-by.

click

[edb49]

Yep, I checked there but also:

94dB Drive-By. Measured from track-side.
100dB Static. 0.5m and 45° from exhaust at ¾ maximum RPM.

(From bookatrack site)

There's different information everywhere it seems.

[LordGrover]

CCC have their requirements.
TD organisers may have additional regulations but must still conform to the circuit regs - assume the worst case scenario.

[edb49]

Interestingly the bike limit is 105dB @ 3/4 revs:

http://www.castlecombecircuit.co.uk/trackdays/bike...

This gets stranger and stranger...

[21TonyK]

From what I've read the testing at Combe is very strict and done in what many describe as the worst environment with sound being reflected back from surrounding garage and buildings etc. Someone somewhere posted that they were measured at mid nineties everywhere else but at Combe they couldn't get on track without additional silencing.

I'm at Combe tomorrow and normally 89db so will report back. I'm also taking mutes that knock a couple of db off just in case.

[silverthorn2151]

Last time we took the Radical there I think it was 98db. We passed static, after fiddling with the exhaust. but then failed drive by, and ours isn't very noisy. We seem to spend more time playing with the exhaust than driving so don't bother goign there any more. 3/4 revs and it's usually quite close to the garage by the circuit exit if I remamber rightly, but I don't think that affected the test.

[edb49]

silverthorn2151 said:

Last time we took the Radical there I think it was 98db.

I guess that was a bike-engined one? Did you measure at 4.5k or 3/4 revs?

[Dan Friel]

Our regs for Saturday state 100dB at 3/4 of max revs at 0.5 metres.

[silverthorn2151]

edb49 said:

silverthorn2151 said:

Last time we took the Radical there I think it was 98db.

I guess that was a bike-engined one? Did you measure at 4.5k or 3/4 revs?

1300 Hyabusa, 3/4 revs (about 6500 rpm usually. It's always a bit vaugue of ours as the rev counter has a mind of it's own and they tend to do it by ear telling me when the revs are high enough.

[edb49]

Hmm. I should be good to get through with my loud bits, but I will take my quiet bits just in case.

[NBirkitt]

We run the VW and Audi track days at Castle Combe and their written intructions to us state (and I quote):

Vehicles will be tested to RAC MSA sound limits as defined in section 'C', 100 dB(A) measured at 45° from the exhaust outlet at 0.5 metres and 4500 rpm (static test)

but it also states that the Motorcycle limit is 105 dB(A) measured at 0.5 metres from exhaust outlet at 3/4 max revs.

( also that Engines must not be run before 08.30 or after 18.00 pm )

[edb49]

Cool, thanks for the clarification.

[Jez200]

C.Combe is always a pain for this. I always end up having to use a bung to pass.
No where else is a problem.

[martvr]

Just to clarify a bit further. The published word appears to cater for all vehicles with the requirement of 100dB at 4,500 rpm. Elsewhere in their literature they state that for bikes it is 105dB at 75% max revs. Nowhere do they cover the bike engined car but be assured that if you turn up with one you will be tested at 75% max revs and the limit will still be 100dB, NOT 105dB.

I've challenged this on more than one occasion, explaining the lack of logic and the omissions in their literature but I might as well have saved my breath.

[21TonyK]

I was 95db at Combe, I'm 89 everywhere else. They do however have my sympathies. They are under so much pressure in terms of planning etc they dare not push their luck. If they did it could be yet another circuit potentially lost.