E30 Zone

bugger -got kicked off donnington today for being too loud !!! managed a whole 3 laps !!

i was measured at 102dBa driveby and their limit was only 98 !!!

not sure what to do as i got them to do a static reading for me and it was 95 at the side of the car and only 92 at the rear . (think one of my silencers has a leak hence the higher reading near the drivers side. However i cant understand how my drive by can be louder than my static by so much. what i am now worried about is induction noise + engine noise + gearbox + diff. even if i get better silencers i dont think i can do anything about these other noises

i dont wantt to be stuck to cadwell and snetterton who dont seem to mind the noise !!. think i will cancel my bedford booking until i get this sorted - i hear they are really strict on noise. the only dilema i have now is how to i know for future - if i do some work on the exhaust system how can i tell if it has done any good to the overall noise reading without booking another track day and taking a risk

help - any ideas on how to get the noise down and how to check it has worked ??

cheers
Jonathan

Jonathan,

I also have noise problems at Donny but mine is with induction, as I`m running a CF airbox wihich resonates, although my exhaust noise is not to bad.

To overcome the induction noise I place cardboard around the air box and this greatly reduces it. I dropped from 103db to 96db. It also helps if you short shift on the straight and keep to the right of the gantry, as that is where the noise is measured.

What car are you driving and what mods have been done, and did you try anything to reduce it, or was it just a thank you very much sir, you too loud.

Cheers,

Dave

I've noticed quite a few cars having problems at donington with the noise limit

I remember seeing one guy using his socks to reduce his induction noise!!

Last time i went this guy with an elise was to noisy because of his exhaust system and resorted to using a a red bull can and black insulation tape

See pic,

Blue Peter stylee!!

I thought donnington was a track, wouldn't they allow noise there for this reason ??

Punch a load of holes in the bottom of a coke can with a screwdriver, slice the top off and a couple of splits down the sides if needed to allow it to slide over the end of the exhaust, then tighten a big jubilee clip to hold it in place on the exhaust. Used it loads of times to kill the noise on me race bike (always carried these bits in the spares box just in case!), will prob work Ok on cars too. It's like an external baffle to disrupt the soundwaves, or so a geeky mate told me

Cheers
Brian

Josemi - Tracks have a licence to run days at different Db limits, some in really tight areas like Thruxton usually have less than a dozen full noise days a year and these are always allocated first to race meetings rather than track days with BSB, touring cars etc taking priority.

I see, not trying to be funny but that is a bugger in my opinion, having a track and not being able to use it to its full potential - unless that trick of the exhaust works and doesn't affect the performance of the cars, in which case then fair enough.

I know its an innocent thought, but you expect of a track to be a place with quasi-permanent noise running through it. That's part of the excitement.

Jose

Josemi - the most ironic thing about Donington is that its right next to East Midlands Airport and we all know how noisy planes are....

well in that case not being able 'make noise' is just ridiculous !

Jose

Too many PC elderly old farts living nearby is the problem, Castle Combe had a noise nuisance order issued and as a result will not be able to hold the British GT / F3 rounds next year, their biggest day as well, bastards!

Ask nicely where the trackside meter is and 'cruise' past it on half throttle/higher gear/lower revs, best way to complete a track day when you've travelled along way.

cruising past is not an option as i was told by a donnington official that there are thre meters around the track and it takes and average (this may be Bull*hit but who am i to argue !)
the guys at bookatrack tried to help and lent me a diffuser the problem is that my tailpipe is HUGE - its like a drain pipe, approx 3". the biggest they had was 2.25". i am going to replace the exhaust system as i suspect my silencer are merely straight though empty boxes = the car was set up for racing which i suspect has higher noise limits. I was so pissed off yesterday i was thinking of selling the car !!!
i guess my cold air intake may add to induction noise. maybe i shoud take that off. i could even go back to the standard crappy airbox i dont have anything too wild - just a cone filter and a standard MAF. not sure what i can do about transmission noise though ??

PS - a big thumbs up to Bookatrack - i appealed to their better nature and they agreed to credit the fee I had paid for the day towards another track day - jolly decent of them !

jonathan

i have had numerous problems in the past with noise issues in the past with other cars - and i decided for my e30 track car which i collected from btb at the weekend to have proper 2 box system which will guarantee i pass 98db. joe says there is no power loss with a 2 box set up and he reckoned the exhaust is only 88db!! - i am sure he will measured it (seems only a little louder than stock and under load has a pleasant but not too obstrusive roar) - this is only 3db more than the standard system and i am running a trick 6 branch with 1, 5/8" primaries. i plan some other mods later on which will impact on noise and therefore i wanted the exhaust to be as quiet as possible so that other factors which impact on a driveby reading will mean i still have some leeway.

i usually go to goodwood, combe, donington - and all have much more more 98db days than the occasional 105db days. i think we have all gotta face facts that noise issues are only going to become more prevalent and if you want lots of track time you gonna have to factor this in when replacing your system - a good exhaust specialist will measure the noise of your car when they fit the system - induction wise i dont have a problem on the e30 but i have a caterham with a cosworth bdg - which is hilariously noisy about 120db - but when that's finally ready and i fit a new silencer to the exhaust - the noise from the throttle bodies will become an issue - and i'll fit an airbox to replace the existing K&N filter set-ups which resonate and cause lots of induction noise. i don't think that will ever get to 98db but i expect to get to a 105db level

i run a straight cut quaife in my 7 with a s/c quaife lsd - and the noise from these don't really figure as part of the overall equation - are you sure that just by sorting your silencer you won't solve the problem - might be worth getting a specialist to build you a proper well engineered system with a brief to get it low as possible with a test after installation - as for primaries bore etc - 1,5/8" primaries is adequate for 2005 BTCC cars and S1600 rally cars so i don't know what engine you are running - but it is gonna have a v.high specific output to make it need bigger primaries - and as for the bore of the system/tailpipe - mine's 2.5" and is quiet - looks like you gotta have to get the chequebook out and get a proper system made if you still wanna play

good luck! ross

thanks ross - the more i think about the more i wonder if donnington were biggering me about. how can i get a static reading of 101 db at 100% revs and 96db at 75% but them get a driveby of 102db which is measured at 8meters away ??

i am going to cancell my bedford booking as there is no chance i will get past the 87db driveby at the moment !!

here is what bedford have to say ::

It is very important that the noise limits are clearly understood to avoid disappointment. These are specified and form part of our planning permission so there is no room for discretionary relaxation.

Although they can seem stringent to some, we operate our Motorsport Sensation programme, which includes Formula Palmer Audi single seaters and the Palmer Jaguars, in full compliance with these limits. They are very reasonable and ensure Bedford Autodrome creates the minimum disturbance to our neighbours.

Please read the following carefully because if your car does not pass, we will not be able to provide any refunds.

At Bedford Autodrome we have two noise tests. First your car will be subjected to a static test, in which the noise level is measured 50cm away from your exhaust pipe with the engine at 75% of maximum rpm. The reading must not exceed 101 dB(A).

Secondly, and more significantly, your car must comply with our drive-by noise limits. The noise emission from your car must not exceed 87 dB(A) measured 20 metres from your car, which shall be accelerating maximally at over 60 mph.

All standard volume production cars will pass this test with ease, so, for example, if you have a standard Audi, BMW, Porsche, Subaru or Mitsubishi you will have no problems at all. The drive-by level will probably be less than 80 dB(A).

Cars, which tend to fail the test include most bike engined cars, eg Westfields, Radicals and Caterhams, plus cars fitted with particularly loud "high performance" exhausts, as sometimes fitted to, for example, Caterhams, Lotuses, TVRs and Subarus. Ferrari 360s can be borderline too.

If you are at all concerned that your car may not pass, it is advisable to either come to Bedford in advance for a noise check, in which case e-mail Clare.Dower@palmersport.com to arrange this, or try to get an independent test done locally to you. You could try www.association-of-noise-consultants.co.uk to find a local noise consultant, but of course there is likely to be a charge.

It must be stressed that the drive-by limit at Bedford is not something that can be "cheated". The noise monitor records continually and we also have other noise meters around the track, so please do not think you will necessarily be able to continue running if you can pass the initial check.