catflap

Just had a new 4inch back box and centre cat removed, its quite burbley, i would like to know if ther is any ball park way of telling if its too loud for a track day?

CraigH

If it's at Bedford and it's more than a whisper you'll get black flagged

catflap

lol, i stand no chance then

markja

The limit at Bedford id 87 Db. THis is determined NOT by the static noise test thatthey do when you arrive, but by drive by measurements on the track. To be fair to Bedford it is the local council that are being a pain in the b*m, they however must enforce the rules (Their sound measuring equipment is connected to the council)

I was black flagged twice on the day and told to go home. I complainted to the organiser (Thanks to Stef for trying to help). The arrangement was is the chief instructor could do two laps past the two detectors without the reading being over 87 dB then I would be alowed to stay on the trackday. I came in at 86.7 dB so I was allowed to stay.
The moral of the story was that it was worth complaining, but the curcuit WILL enforce the rules. I drive an Evo (for my sins) and I do not consider it expecially loud.
If you at all uncertain, then it is worth checking out before hand. Even at the exceptional value of 140 GBP, I would have been extremely pi**ed of at having to go home early.

Apart form that it was a fantastic day out, and i would like to stay a huge thanks to all of the drivers for being so well behaved, the behaviour of all the people, (unfortunatelly) is far better than at LTR meetings, and it was a pleasure to be out on the track.

Markja

catflap

what have you done to your evo to make it that loud then? well acording to their limit?

CraigH

Mark,

Where you the Black EVO?

If so, we were commenting on how we couldn't believe you hadn't been black flagged - the exhaust isn't noisy, but the turbo.....

87db is damn quiet - I thought the limit was 101db?

87db is as quiet as std I think....

My car was quiet with the bung in - but that only just came in at under 101db.....

But then there were laodsa cars there that I thought were louder than mine.....

Didn't seem consisteent (to my ears) but it obviously was.

I think for future days, a very very visible noise warning should be included with the info.

markja

My Evo is actually one of the quieter ones. I have a full HKS system. (Downpipe, de-cat, rear section).

The problems with Bedford is that if two cars go past the measuring staions togerther (or very closely) then the system is not smart enough to differentiate between the two. It is also possible that it was my dump valve rather than my exhaust that was causing the high noise level as I was changing gear right next to one of the sensors

markja

Yes I was the Black EVO

It is interesting to hear that you think the Turbo was loud, compared with the exhaust. Do you mean induction noise or Dump valve 'woosh' ? From the inside of the car you dont really get any impression of the noise.

Most other race circuits are arround the 100 dB limit, I have no idea why Bedford is so restricted (There must be a local councilor who lives near by).

It is a good idea of yours that the track limit is published clearly on all of the information sheets. I dont know if anyone was actually sent home on the day, but I know that at least four cars were black flagged during the 15 mins that my car was being tested.

chuckster

Bedford (and a few others) have a static limit (101db measured 0.5 metres from exhaust) and a 'drive by' limit (87db measured from a distance as the cars accelerate fully) . Different cars make different readings. I;ve seen a full scoobysport car read 103db static, and I've seen many full scoobysport cars read < 100.
Most trackday organisers are as flexible as possible about it, I seem to recall at our favourite track they make a point of telling you to pass the microphone on the other side of the track, or even lift off if nescessary as you pass.
My cars not tuned enough for me to bother with a downpipe anyway, so I;m not bothered LOL
Chuck