Ariel.Club Forum

Static 96 @ Bedford GT with Atom 4 320 Standard Exhaust at 4,500, was warned that it may be an issue on track with drive-by, they were very good and advised to ask them before going out where the microphones were located and to be in a gear higher when passing. I didn't bother as I knew that I would get a noise board and then one black flag chance, so could adjust my driving if that happened. 38 laps later no problem at all, I definetly didnt lift or short shift for any of the drive-by mics ...

[quote=CAG3D post_id=305490 time=1627657264 user_id=5629]
What sort of times are you lapping at castle
Combe in the 4?
[/quote]


running on Avon ZZR's and no wings.
1:17.1 was my fastest. I feel there is another 2 seconds to find if I could nail it. I brake well early for the legendry Quarry and other corners.

102 at Cadwell 350 with standard exhaust at 4,500
98 at Croft 350 with standard exhaust at 4,500
105 at Bedford 350 with standard exhaust at 4,500

Seems to me, all depends on what decibel meter they use and the distance they measure from..This seems to vary from track to track.

What sort of times are you lapping at castle
Combe in the 4?


Sent from my iPhone using Tapatalk

[quote=dooke2000 post_id=305487 time=1627654226 user_id=6145]
Atom 4 350bhp decat standard exhaust at Castle Coombe reading of 99db
[/quote]

SNAP. Exactly same. Forgot to update this thread. :o

Atom 4 350bhp decat standard exhaust at Castle Coombe reading of 99db

I will retest this weekend if I can find a window in the continual rain! :-\

There are too many aspects of sound testing to replicate at home with any mic:
*weighting
*reflection/absorbtion (ie. the environment in which you test and generate the sound)
*distance
*mic itself (mostly how directional it is)

You could use a mic in an open environment to some extent to angle the exhaust tip, if that's a feature. At one of my tracks they have a live mic readeout. You could have a friend monitor it as you adjust the exhaust. That's way better.

Has anyone been to Donington yet (my favourite track).

I am thinking of Atom 4 350 with sports exhaust. Will this fail their drive by limit?

I will submit my noise tests once I get my Atom in about 5 months.

[quote="Old Bill" post_id=297987 time=1582294891 user_id=2910]
Went there 2018 with my pal in his 3.5 and we both registered 90 dba,strange as my readout is always 92/93. Static.

Different in the 4, my static at Bedford was 95 and I had the "noise" boards waved a few times, with standard exhaust.
I don't think I'd risk a Thruxton track day now, but we will be Ok for the Atom bash apparently.

Bill
[/quote]

Thanks for that Bill. :tu: When the howling wind stops i will measure my car and add to the list. When tested in the wind (even with a foam wind protector on the noise meter) my 4 was over 100dB(A) @ 45% and 0.5m from the exhaust tips @ 4000rpm. :o But the wind was visible effecting the readings significantly. ::)

Went there 2018 with my pal in his 3.5 and we both registered 90 dba,strange as my readout is always 92/93. Static.

Different in the 4, my static at Bedford was 95 and I had the "noise" boards waved a few times, with standard exhaust.
I don't think I'd risk a Thruxton track day now, but we will be Ok for the Atom bash apparently.

Bill

Anyone been to Thruxton in an Atom?

Static 90 dB(A) at 3/4 max revs seems VERY low. :td:

I guess the surroundings have a big impact. With noise bouncing off buildings etc.
Plus the meters are set certain distances on certain points of the track.
I had a black flag at Bedford, with my STANDARD exhaust, so when called in they told me which one was picking me up and suggested a higher gear (yeh right!), or try to take a wider line, which I did, and all was fine.
So it all works on small margins and a number of different factors too.



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My view is that the cost of a dedicated noise meter is significantly less than even a cheap track day so its well worth having to avoid any worry over black flags.

I think it will be a useful and interesting tool to bring along to meets where I can test peoples cars and post up the results here.

Peter
:vroom:

Simon

I fully accept your very valid points however I was really only intending to point out that these apps can give an idea of the noise level of your car.

As to the frequency response of smartphone microphones it rather depends on the quality of the phone used - certainly some iPhone models use dynamic mics which have fairly narrow frequency range microphones fitted but anything that gets from 200hz up to circa 20000hz (small diaphragm condenser mics) or higher should be fairly adequate for the job!