James159

Looking to book up another track day this month, but have an issue with the noise.

The day I'm wanting to book is a 98db day. I was at Croft last year and this year (they never tested the car this year as I only went on on the afternoon?) and the car was 99/100db if I remember.

Anyways, borrowed a friends DB tester (CEM DT-805) and it made 96ish at at 5k revs. Thought I would double check so I drove to the circuit to be 100% and it read 107db at 5.5k ish revs on his meter! The two noisy days I done at Croft are 105db days, so surely they would have black flagged me, but they never have.

There was a Javelin day on today (88db) and I saw an Evo and Celica turbo flying round which seemed just as loud as mine to be honest! Can't work it out at all....

Are these exhaust bungs safe for your car? I know they obviously reduce the flow of the exhaust gases. Thinking maybe to pop one in when I get initial test?

JGlanzaV

iTrader: (3)

Safe if you don't want to drive on boost!!!! Don't drive on full boost with it in that's for sure! Will increase your EGTS etc.

Would work for initial test but you still might get flagged on the track if you take it out.

Why not just get a more sensible exhaust if you want to track it?

James159

Yeah, didn't think they were safe if you were wanting to drive on boost.

I do/have done track days in it. Like I said, usually go to the 105db days and have never had an issue at all. That's why I was puzzled with his 107db reading today!

JGlanzaV

iTrader: (3)

Did they do the test in the usual location?

Sound testing has to be done in a very specific way to be accurate, in between buildings etc will be louder than in free air.

Steel wool is a cheaper alternative to a bung btw

James159

Same place ish to be honest mate.

I'm guessing the cars I saw today got away with holding revs really low during testing, instead of the three quarters? No way were they 88db!

JGlanzaV

iTrader: (3)

All depends what they tell them the rev limit is

I've passed noise tests by the pigs by telling them my rev limit was 6k rather than 8k, can't prove it, but I shall get a rev limit mapped in on my alkatek for such occasions

rooferman

iTrader: (6)

Won't make a difference if you can pass the static tests by blagging rev limit ...

Nearly all tracks have trackside meters that will pick you up and you will get flagged. Noise is a serious issue at most tracks and we all need to adhere to it for the future of trackdays/track usage/competition etc....



Better to just get a track friendly system imo....

James159

Yeah I understand they have static flyby testing also - was fully aware of that.

What I don't get then, is if my car made 107db today - why haven't I been black flagged on the 2/3 previous 105db days then?? On the same days, there were cars much louder than mine too (alot of the modded Jamsport track cars etc)

Those track side meters surely would have picked up the 88db plus reading of that Evo and Celica turbo today too!

Think it's best to just say with the 105db days then.

rooferman

iTrader: (6)

They vary from track to track.....and you'd be a brave man to question the equipment or accuracy at any event....they will simply ask you to leave..

I used to run a ridiculously loud system as was o.k at Santa pod and the likes...measured 117 db at elvingtin once...but it becomes a pain when your asked to leave !

Castle coombe must have the worst d.b testing I have ever experienced.... they are a nightmare and rude with it.....but if you want to enjoy motorsport you have to get in with it.

Revolution system on mine now breezes through 98 d.b tests and it's nice to not get the hassle anymore...

Fonzey

iTrader: (5)

These trackside DB tests are complete bollocks and it's irritating if you're close to the limit.

I've done four javelin trackdays and three of which on the same exhaust. It's a TSL thingy and on my first trip to Blyton (no static, just drivebys) I got several warnings during the day and was approached in the paddock to see if I could bung it. I never once EXCEEDED the limit, though apparently was close.

Next time out, I took my PPP backbox in the boot incase I needed it - didn't want to risk a black flag. Never got so much as a second glance and no warnings.

Trying to do your own static tests is just a waste of time too, as the surroundings/atmosphere/time of day/colour of the operators socks/etc all have an influence on the output. If you're anywhere near close, take a spare backbox or a bung.

The outcome of exceeding the limits is harsh, being excluded from the day could be the end of a several hundred quid investment - and as they've got no consistent or reliable way of policing it, it's all the more frustrating.

rooferman

iTrader: (6)

Jetex do some good silencers that are not restrictive....

Think the "banana" uses one and the exhaust is only 3 feet long.....it's as quite as a mouse !

rooferman

iTrader: (6)

Problem is the track owners can face serious fines for noise infringements...

Donnington for example have had trouble and they have jumbo jets taking off above them ! ....and Richard who owns Blyton Park had had some problems recently.

James159

Yeah, bet it's a right pain in the *** being asked to leave.

Not a huge track player though to be honest - a couple a year do me.

All the readings/testing figures I have given are from the same track though, which makes it all a bit odd.

The days that's come up is reasonably priced and I'm off work that weekend. However, the fee is non-refundable apparently so don't really want to pay to get told to get lost before even getting on the track!

Fonzey

iTrader: (5)

Yep no doubting that the track owners are under pressure, which is another argument completely (I'd never get bored of the trackday soundtrack whilst sitting out in my back garden...). I'd rather harsh limits than to see the end of track days, but it's difficult to build an exhaust system around a moving target!!

mickywrx

iTrader: (29)

Get a Revolution exhaust, then you can stop worrying, IMO.

Noise testing can be very strange at times, last time I ran at Elvington my car recorded 89.5 Db. 3/4 throttle and measured half a meter away or whatever distance it is.

Nur Spec R with no bung in.

Fonzey

iTrader: (5)

Yep my next will be a 3" Revo end to end I reckon.

rooferman

iTrader: (6)

Understand fully the moving target.....

Ginola

iTrader: (25)

I have a cobra trackday friendly 3" system, and it generally measures around 92/96db, sounds great.. It has never pinged any drive by's. (Goodwood/Brands etc)
However go for a noisy day with a slash angled jap H&S backbox on the back and even with double resonated centre section I was black flagged on a drive by.. (passed the static with 1db to spare 104 on a noisy day) Lucky I bought the cobra backbox and switched back so it didn't ruin my day.

FYI the revolution exhaust while excellent for track days i'm sure is slip jointed so you can not easily swap back boxes etc.