***TRACKDAY*** Cadwell Park 26 June

Casey · June 19, 2009, 09:09:12 AM

Quote from: TiddlesRX7;617898Im starting to worry about how loud mine is now. What can I do to quiten it down a touch if need be?

Remember that noise level measurements in dB is on a logarithmic scale, not linear. 0dB represents the threshold of human hearing, and each 10db increase represents a perceived doubling of the level of sound to the human ear. So, at 95dB the sound level would be at 50% of the permitted max of 105dB (not 105/2=52.5dB as normal "linear" maths would imply). 55dB is likened to a low volume radio at 1 metre. 105dB is likened to a F1 car at 40 metres, typical close trackside viewing distance. I haven\'t been to live F1 for a few years, but I found the level of noise to be such that a lot of people viewing trackside wore ear defenders, as do all the pitlane people.

One problem with all this is the "A" bit in dB(A). The "A" refers to the "weighting" factor given to various frequencies in a sound. The idea is to try and measure in the way a human ear perceives sound, which is very frequency specific. So the frequencies present in your exhuast "note" will have an impact on the measurement. That\'s why it\'s so difficult to know how "loud" your exhuast is by simple perception, a proper noise measurement is the only way to know for sure.

Be warned that they can be quite strict on these tests, so a noise test or some means of quietening on the day might be wise. Just "be nice" to the guy doing the tests in the morning, and try and find a spot in your rev range that seems quieter, and hit that spot if possible during the test. They ask you to run at half revs during the test, but they won\'t (usually) check exactly on this point!

TiddlesRX7 · June 19, 2009, 11:20:52 AM

Well on Shauns metre it was 104.5 at around 4.5k-4.7k so hopefully it\'ll be ok as half revs can be seen as 3.5k-4k.
The exhaust is made by a company called Motoria (think thats correct spelling). It was on the car when I got it and the car has been used as a track car/ time trial/ hill climb car in the past so I hope it will be ok.
Although I might bring a box of toffies to offer as a bribe just incase!

overboost · June 19, 2009, 11:34:20 AM

Sounds fun!

Anyone knows if my 180km/h limiter is going to be a problem on the main straight?

I am getting a power fc soon so want to do a track day before that just for comparsion.

najiru · June 19, 2009, 01:33:44 PM

I\'m bringing a bung as well just to be sure although I really don\'t want to have to use it. 101db seemed pretty loud to me!

Casey · June 19, 2009, 04:23:14 PM

Quote from: overboost;617994Sounds fun!

Anyone knows if my 180km/h limiter is going to be a problem on the main straight?

I am getting a power fc soon so want to do a track day before that just for comparsion.

Yes, the limiter will be a problem. 180km/h=112mph; I\'d be expecting to exceed that at Cadwell in my RX-8, based on the fact my terminal speed on the shorter main straight at Brands Hatch was typically 115mph. I know that Clive spoke about removing the 112mph limiter from his imported RX-8 as he also knew it would be a problem.

Casey · June 19, 2009, 08:00:51 PM

***SOUTHERN CONVOY DETAILS***

OK folks, just back from a very hot and sunny break in Cyprus and now less than a week to go to this

If anyone wants to convoy up to Cadwell on the Thursday, CrissyUK and I will be travelling up as follows;

1st Rendezvous, leaving at 1.30pm
Fowlers Farm Pub car park, Braintree Rd, Cressing, Braintree, CM77 8DJ
Casey
CrissyUK

2nd Rendezvous, leaving at 3.30pm
Peterborough Services, at A1 Junction 17 (junction with A605)
Casey
CrissyUK

Anyone else is very welcome to join us at either place, just add your name to let us know

probedb · June 21, 2009, 05:47:08 PM

I\'m really sorry but I can no longer make this

It\'s all paid so if anyone knows anyone that can take my spot please do so!

Casey · June 21, 2009, 07:15:06 PM

^^^^^^^^^^^:eek:

Noooooooo, so, so sorry to hear that Paul. Anyone lurking on the thread who might be tempted to take Paul\'s place?

BTW, is there anyone who needs a helmet on the day, size M (58cm), as CrissyUK has a spare one she can bring along (would save the Â£10 hire fee)?

probedb · June 21, 2009, 08:18:12 PM

I know

It\'s open to takers now so hopefully someone will be able to fill!

Casey · June 22, 2009, 04:56:09 PM

^^^^^^C\'mon, there must be someone who\'s itching to do a trackday and can take up the place that probedb unfortunately can\'t now use?

NOISE;
Just got this "official" statement of noise mesurement. Note, noise measured at 3/4 max revs....

"Noise Limits

All vehicles participating in track days at Cadwell Park must conform to the noise limit, on a static test, of 105 dB(A). Noise checks to establish adherence to the relevant limit will be conducted in accordance with current measuring methods as defined by the MSA. Essentially this means that the noise test shall be measured from a position 0.5m behind the exhaust at a 45 degree angle, with the engine running at Â¾ maximum revs"

antnicuk · June 22, 2009, 08:57:02 PM

good news and bad news.

I noise tested the kit car today, the new silencer has brought it down from 104 to 96

The 20b FD is playing around, the coils look like they are giving up and Dave has work commitments and cant get it sorted in time so there is another place up for sale

I have also reserved a twin room which i will be staying in but there will be a spare bed if any of you have passengers that need a room, bargain of Â£27 for B&B

I will be trying a few friends to see if they want it but as Probedb pulled out first his place should sell first on here.

HypoThermia · June 22, 2009, 09:00:52 PM

Rotaries don\'t rev that high do they? :Hammer

Hope you get that spare place filled...

Ian.

clive · June 22, 2009, 09:55:15 PM

Quote from: HypoThermia;618920Rotaries don\'t rev that high do they? :Hammer

Hope you get that spare place filled...

Ian.

Ian,

How about a rental RX-8 for the day, just a thought, I\'ll get me coat.

shaunwil · June 22, 2009, 11:08:24 PM

Just started the bedding in of the HP Plus pads tonight, my god they are awesome ! First time the ABS kicked in on a dry road ! Can\'t wait to see how the new fluid holds up too !

Shaun

Casey · June 23, 2009, 02:50:24 PM

Quote from: HypoThermia;618920Rotaries don\'t rev that high do they? :Hammer

Ian.

Yeah, I recall at Brands Hatch that an RX-7 owner with a loud exhaust only revved to about 4000rpm for the test. In any other car that would have been about 3/4, and unless the tester is very knowledeable, it might work if you are concerned you are at the edge on noise;)