Getting below 95dB.

rookie2006 · 30 Jan 2006, 16:08 (Ref:1511995)

I've recently purchased an FF1600 and am doing my first test at Bruntingthorpe next week. However, I've been advised that the allowed noise limit there is 95 dB max. The chap who sold me the car says its unlikley to get below 100 dB. Does anyone know a relativley cheap way of beating this noise limit ? The car is fitted with the standard ford muffler/silencer.
Many thanks for any advice.

kickstart · 30 Jan 2006, 16:40 (Ref:1512016)

I think the real answer is not to test at Bruntingthorpe with a 95dB limit. Race circuits on test days normally have a limit of 108dB for single seaters, which you will be fine with.
You can test at Mallory every wednesday for about £90. Othwerwise you need to look at one of the noise trap things that are sold be Demon Tweeks and others, but I really would not guarantee that you will be able to get down to 95dB.

andy97 · 30 Jan 2006, 17:21 (Ref:1512038)

"Track and Race Cars" magazine do their track tests at Bruntingthorpe all of the time and they have tested some very meaty machinery in the past - I can't belive that the Juno was below 95 dba, for example.

The local aircraft preservation society also runs its pair of Lightning fighters up and down the runway on open days!!!!!

Perhaps the limit is (hmm, cough), advisory........!!!

Redracer77 · 30 Jan 2006, 21:51 (Ref:1512236)

what is the MSA noise limit?

mattray · 30 Jan 2006, 22:13 (Ref:1512260)

random fact of the day, every 3 decibels the noise is doubled, its not a linear scale. So to try and reduce the noice by 6 decibels would be a lot to achieve!

I think 105 is the MSA limit but thats off the top of my head so might not be.

HH Tech · 30 Jan 2006, 22:17 (Ref:1512264)

Hello
I use the small FF silencer cut so I can repack it and just manages 95dB (pass by noise) my friends big FF silencer (cut open both ends to repack) is eaven more quiet.
I usally have to repack the silencer every 2hrs running when about 25% have burnt away, repack with fiberglass

Henrik

mattray · 30 Jan 2006, 22:21 (Ref:1512272)

Plenty of those knocking around now since the strange introduction of the new type! interesting how they can just change the silencer without any apparent warning (I realise it still has the same part number on it, but its an entirely different internal!)

Redracer77 · 30 Jan 2006, 22:32 (Ref:1512288)

my new stainless F4 exhaust can be re packed if needed. Not that I know what to pack it with!!!

HH Tech · 31 Jan 2006, 08:12 (Ref:1512498)

Hello
Demon Tweeks sells "exhaust wadding"
http://www.demon-tweeks.co.uk/produc...pcode=CCLWADD1

I repack mine with leftover glassfibre mat you can probably get a large bag for almost nothing at you local guy who make glassfibre products. Use as long strands as you can obtain, ie rowing or continious fibre.

Makes a real difference to the sound.

Henrik

heel'n'toe-no · 31 Jan 2006, 13:12 (Ref:1512705)

Quote:

Originally Posted by Redracer77

my new stainless F4 exhaust can be re packed if needed. Not that I know what to pack it with!!!

Afterburner fluid Chris......

Now that your on wings 'n' slicks

Redracer77 · 31 Jan 2006, 15:03 (Ref:1512763)

picked the car up this morning from JP Exhausts - fantastic job for not massive money

DALY · 31 Jan 2006, 21:48 (Ref:1513057)

interesting fact Mattray, you are an educated scholar!!

Drive by noise tests are different to assembly area type tests, at Donington I first tried out my Reynard 89 under slung system, stationary it was fine, drive by it was over 100db, so a short tail pipe cured the problem.

So maybe if you polish your pipe, add stainless steel and be happy like rr77 all will be fine

mattray · 31 Jan 2006, 22:52 (Ref:1513098)

Educated yes, no good at building engines though!

HH Tech · 1 Feb 2006, 07:59 (Ref:1513275)

Hello
Check out where they take the drive by noise reading
A 45 or 90 deg turn at the end of your tailpipe can make a difference or change up a gear just before ................

Henrik

JohnMiller · 1 Feb 2006, 08:08 (Ref:1513280)

Back to the topic, unless you just want to pootle around and get used to driving the car, Bruntingthorpe is really not suitable for an FF1600 at all.

Crunch · 1 Feb 2006, 23:28 (Ref:1513880)

What's Bruntingthorpe like then John? And is there anywhere else a rookie can test before they get an ARDS test and a licence?