checking noise level SE?

[tim_930]

Hi,

I want to start doing trackdays this year, but I'm concerned about the noise level of my 87 911 Turbo as it's got a sports exhaust on it. It's very loud and I want to get an idea of the Db level before I book somewhere only to get turned away.

Is there anywhere in the South East that can measure it for me?

Tim

[atlanta]

Hi,

If you attend one of RMA's Trackdays we are on hand to provide bolt on silences, flat floor facility's and repair work to keep you on track and get you home.

Ben from Atlanta Motorsport

[calypsoelise]

If you call in at Goodwood they're normally happy to do it for you. Maybe ring first.

[Bruce Fielding]

Bookatrack will post you a meter for about £9.00 inc. prepaid return envelope. Check your dB at home!

[kickstart]

If you are going to noise check your car - remember to do it at 3/4 max revs with the noise meter 1 meter away (i think but check the MSA blue book or give them a ring)
I would guess that you will be somewhere between 98dB and 105dB but it would have to be really quite noisy to be over 105dB. There are lots of trackdays at 105dB

[tim_930]

Thanks for all the replies. I like the idea of getting it checked at Goodwood as thats my nearest circuit anyway.

Does anyone have a number for Goodwood circuit?

Tim

[Rocket123]

Alternatively ring RAC Motorsport 01753 681736 and ask for a sound scrutineer who lives near you. The scutineers are usually motorsport enthusiasts that work part time on rallies etc, and are more than willing to help. If you live near Hampton Court the local sound guy is Den Duber 0208 979 9592 and has tested my exhaust before.

The important things to know to get through sound tests are:
1.Warm the engine up really hot first
2.Depress the clutch
3.Keep your window only 1 inch or so open
bring up the revs very very slowly to the required amount and at your own pace (don't be pushed into raising revs too quickly by a scutineer who thinks your just trying to rev the car less than requested-common occurance).

Rocket

[tim_930]

Hi,

Goodwood are more than happy to do it, you just need to ring first before going down there....

off to the pit lane, sometime this week.

cheers
Tim

[griffany]

Rocket123 said:

Alternatively ring RAC Motorsport 01753 681736 and ask for a sound scrutineer who lives near you. The scutineers are usually motorsport enthusiasts that work part time on rallies etc, and are more than willing to help. If you live near Hampton Court the local sound guy is Den Duber 0208 979 9592 and has tested my exhaust before. The important things to know to get through sound tests are: 1.Warm the engine up really hot first 2.Depress the clutch 3.Keep your window only 1 inch or so open bring up the revs very very slowly to the required amount and at your own pace (don't be pushed into raising revs too quickly by a scutineer who thinks your just trying to rev the car less than requested-common occurance). Rocket

Hey
Good sound advice, bang on the nail!
Regards
Griffany

[Melv]

kickstart said:

do it at 3/4 max revs with the noise meter 1 meter away

Careful there!! For instance:

Combe 3/4 max revs at .5 metre. 100db limit

Goodwood 3/4 max revs at .75 metre. 98 db limit (ten car day) or 105db limit (five car day. Plus independant track side mics.

Bedford 3/4 max revs at .75 metre. 100db limit plus track side mics.

They also do not take into account whether test done on tarmac or grass, whether vehicle front or rear engined, barometric pressure, wind direction and weather -all factors which will affect the final reading.

I understand that the ACU have a far more scientific method....

Having clutch out can mean a 2db difference.......