The Track Noise Thread

Post by **campbell** » Sat Aug 31, 2019 1:35 pm

Add your car / exhaust combo with test results.

Feel free to add any tracks whose lots you know.

Known track limits
(dBA static / drive by)

Oulton Park - 104 / ?

Donington Park - ? / 98

Car & exhaust combo test results
(all in dBA, static, at approx 2/3 rev limit)

Exige Sport 380 (Clarkie) - valved factory exhaust - 100 (valve closed), 105 (valve open) @ 4k rpm

Elise S 2ZR (Campbell) - 2bular QP exhaust - 90 @ 4k rpm

Post by **C7Steve** » Sat Aug 31, 2019 1:44 pm

https://catdrivertraining.co.uk/track-d ... mit-guide/

https://www.javelintrackdays.co.uk/trac ... ise-Limits

http://www.donington-park.co.uk/residen ... ns-dp.aspx

Some limits from the UK tracks below.
Static (dB)
Drive-by (dB)

Anglesey
105 (95 on quiet days)
101 (77 on quiet days)

Bedford Autodrome
101
87.5

Brands Hatch
105 (evenings 102)
92

Bruntingthorpe
98
87.5

Caldwell Park
105
n/a

Castle Combe
100 (at 4500rpm)
94

Croft
105 (88 on quiet days)
70 (average over an hour)

Goodwood
105 (98 with >9 cars)
101 (96 with >9 cars)

Knockhill
105
n/a

Lydden
105
n/a

Mallory Park
105
n/a

Oulton Park
105
n/a

Mondello Park
105
n/a

Pembrey
105 (102 for bikes)
n/a

Rockingham
105
103

Silverstone
105
n/a

Snetterton
105 (102 evenings)
n/a

Thruxton
90
n/a

Zandvoort 88db(A) Drive By at 20 meters from centre of track & 105db static.
The limit will be strictly enforced. It is strongly advised that cars are fitted with a cat – most need one to be road legal.

Zolder is 98db Drive By at track side. This is higher than the advertised limit when most of you booked. Transponders are fitted to all cars so that the circuit can pin point noisy cars.

Clarkie · Post by **Clarkie** » Sun Sep 01, 2019 10:40 am

Thanks to Jen and Campbell for organising yesterday & Rennie for the tips/results

“Exige Sport 380 (Clarkie) - valved factory exhaust - 100 (valve closed), 105 (valve open) @ 4k rpm”

Revs were slightly more, was trying to hold at 5k, as the revs pass 4K, presume the vacuum opens the exhaust valve as the revs pick up pretty quickly
Need a bit of practice with static throttle finesse

Red line for the 380 is 6500 so revs at 2/3rds will be 4329, a slow build to there should be just fine. I’ll look at the Komotech pipe work Malcolm mentioned too

Kinger · Post by **Kinger** » Sun Sep 01, 2019 2:10 pm

Clark,
You should bring it to Zolder next week, you’ll get a very accurate drive by reading when you’re black flagged after two laps

istoo · Post by **istoo** » Sun Sep 01, 2019 5:02 pm

How is the noise measured? Ie is there a meter somewhere on every track, ie could you lift off whilst passing it...

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a4drk · Post by **a4drk** » Sun Sep 01, 2019 5:11 pm

I managed to get 104.8db at Zolder with a 95 drive by limit.
Going there next week - but I’m prepared by having a plug in silencer.
Tested it at Donington a couple of weeks ago. It measured 93 !
I’ll try and up load a video clip of it
Nick named it “ Sally Gunnell” ...... Ugly, but effective

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a4drk · Post by **a4drk** » Sun Sep 01, 2019 5:13 pm

Donington- that’s a joke - it’s right on the flight path - planes are at 1000 ft above you taking off

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a4drk · Post by **a4drk** » Sun Sep 01, 2019 5:14 pm

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Scottish Scrutineer · Post by **Scottish Scrutineer** » Mon Sep 02, 2019 7:47 am

Glad I could help out on Saturday Clarke and Campbell.
Just to share the tips I gave for passing static noise tests:
Make sure the car is fully warmed up
Know what your rev limit is, you may want to round it down

If you’ve got a valve controlled exhaust, know when that valve opens. Keeping it below that can make 4-5dB difference.
Bring the revs up slowly and then hold it steady

Renny

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greyrigg · Post by **greyrigg** » Mon Sep 02, 2019 9:08 am

I have found with the 380 raising the revs very slowly will keep the valve closed. Mine tested at 89db at Castle Combe. It takes a bit of practice to get it right and if you go too high and bring the revs down it is too late (105db at Croft but got a second shot as it was just on the limit).

Malcolm

Post by ed » Mon Sep 02, 2019 12:53 pm

Scottish Scrutineer wrote: ↑
Mon Sep 02, 2019 7:47 am
Glad I could help out on Saturday Clarke and Campbell.
Just to share the tips I gave for passing static noise tests:
Make sure the car is fully warmed up
Know what your rev limit is, you may want to round it down
If you’ve got a valve controlled exhaust, know when that valve opens. Keeping it below that can make 4-5dB difference.
Bring the revs up slowly and then hold it steady

Renny

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Thanks for the tips!

Post by **campbell** » Mon Sep 02, 2019 8:54 pm

Renny,

Big thanks from me too. Sorry I missed you to say thanks when done!!

Agreed too, great tips for “managing the noise level” during testing.

See you again I hope.

Campbell

Clarkie · Post by **Clarkie** » Mon Sep 02, 2019 9:27 pm

Kinger wrote: ↑
Sun Sep 01, 2019 2:10 pm
Clark,
You should bring it to Zolder next week, you’ll get a very accurate drive by reading when you’re black flagged after two laps

alicrozier · Post by **alicrozier** » Thu Sep 05, 2019 3:24 pm

From ZZ19 finals:

Zandvoort 88db(A) Drive By at 20 meters from centre of track & 105db static.
The limit will be strictly enforced. It is strongly advised that cars are fitted with a cat – most need one to be road legal.

Zolder is 98db Drive By at track side. This is higher than the advertised limit when most of you booked. Transponders are fitted to all cars so that the circuit can pin point noisy cars. We will include procedures and information on noise testing at the briefing.

Post by **C7Steve** » Thu Sep 05, 2019 5:45 pm

I have added your information from Zandvoort and Zolder to my post at the top.

Cheers Ali.

Steve.

Scottish Elises