Noise limit's..how to test?

[Man On The Clapham Omnibus]

Have a look at my Wunoff silencer on my Pinto engined car. It just about scrapes through 100dB(A) at MSE trackdays with a reading of c.98dB 

 

[Keith B]

Thanks all.....I shall run it up to Oulton park on their next track day and ask them for a sound check😉

[Burgerbob]

Hi All

 

I recently purchased my first Westie, which unfortunately is currently off the road in storage.  Next year I'm planning on doing a few track days, ideally doing Bedford first.  I've been there before and think it would be a great place to get to know the car before trying a few other tracks.

 

Anyway, I've no idea how loud it is but with Bedford being the strictest of tracks I'm a little nervous.  My previous car was a tin top so its very difficult to compare!  Appreciate that the only answer is to get it tested, but with it being in storage, battery disconnected etc that's not so easy.

 

The car is a 1.8 zetec on throttle bodies (but not protruding) with 160bhp.  The exhaust is a custom made exhaust.  Well made but not the biggest of silencers.  Pic below.

 

Do many zetecs of around this level of tune fail the noise test?  i.e. am I likely to be worrying about nothing (although, having not heard it, I get you can't comment on my cars noise levels!)?  

 

The alternative is to book somewhere like Cadwell for the first track day, but I'd prefer a track I've been to before with more run off - hence why Bedford.

 

 

[Kit Car Electronics]

It's good if your throttles are still hidden inside the bonnet - a lot of the noise is often from induction with exposed filters. I'd guess the cat will give a small amount of reduction, but the actual silencer does look on the small side... 6" diameter is normally a minimum for an effective can.

[Mole]

Bedford is the only place I have had an issue..but that is with right side silencer and with noise meter pick up on that side..

Bedford were very fair and gave me heads up..so I just did short shift at that meter..

If you get through the static test then I would guess you would be ok when on track..and just build your revs up sensibly...

Silencer does look small though...

[TAFKARM]

Get a noise test at Donington which looks local to you. MSV own both so should be comparable. 
 

You won’t get on at Bedford with that can IMO. 

[Burgerbob]

Thanks both - I did contact Donington but they said they don't have the facilities to do a static test as its a drive by test there.

 

I think the only sensible option is to either buy a cheap meter, or download an app, and measure it.  As long as its not borderline I'll get a steer if it'll pass or not.  I don't fancy the drive to Bedford, to only get turned away, losing the cost and one of my 5 track day insurances.  The car is SORN'd, battery removed etc so it'll have to wait for a bit.  But I'm not planning on taking it out till Feb / March time so I've got a while yet.

 

The other option is to buy one of those things to shove up the exhaust pipe, but I don't really fancy that and being a curved pipe I'm not sure how easy it'll be to fit.

 

Or I could just say sod it and book a day at Cadwell.  I want to go there next year anyway, but ideally intended to get to know the car at a more forgiving track first that I've been round before.

[Oily Steve]

I would suggest Blyton as a starting venue. It’s a track that usually has plenty of dates available, reasonable prices and I think is a good track to start with plenty of run off in most places. Many of us from the club have been there before and it suits Westfields I think. Also I have never seen anyone have a problem with noise there.

 

Cadwell and others are great tracks but are probably better to do after some experience has been gained elsewhere, in my opinion.

 

[AdamR]

^^ 100% agreed.

[Burgerbob]

Blyton is a good shout.  Bedford appeals as I know the track and it's fairly forgiving meaning it would be a good place to get to know my car.  But I'm nervous about the noise.

 

Never been to Blyton, but on paper it appears ideal, plenty of run off, more relaxed on noise, plenty of available days at a decent price!

 

I've got 5 track days included in my insurance next year, and I fancy Cadwell, Anglesey and Donington.  Blyton looks like the best place to try the car out, see how we get on, check the noise levels etc then see what comes next!

[Mole]

Agree.. Blyton perfect for all those reasons... And many weekend dates too..

[Castlecroft]

Blyton?... hmmm... last year we had three visits from the sound police... busted the drive by noise limit by the monitor that is 20m after the start line over the two days meeting...... ended up short shifting till we were past it...

and before any suggests that the wind was in the wrong direction... the well qualified noise police assured us that the wind direction has nothing to do with it...

 

we are running a standard busa... we’ve never had any problems with noise at any other track, sprint or hill.... Blyton is off our “go to venues” as a result....

 

[Andrew]

My son pinged the Blyton drive by (95db) earlier this year in his CRX. He was given a fingers in ears signal by the marshal, and just had to short shift past the meter.  The point being, he didn't get chucked off.. was able to continue for the rest of the day. Blyton's definitely preferable to Cadwell for exploring the limits of an unfamiliar car. 

[Tim Reid]

I hold a proper noise meter for the Thames Valley area. It was bought by a previous AO and left with me for anyone who want to come to one of out meets (every second Sunday of the month).

Just let me know in advance to I can put it on the passenger seat.

[Burgerbob]

On 01/12/2019 at 18:20, Burgerbob said:

Hi All

 

I recently purchased my first Westie, which unfortunately is currently off the road in storage.  Next year I'm planning on doing a few track days, ideally doing Bedford first.  I've been there before and think it would be a great place to get to know the car before trying a few other tracks.

 

Anyway, I've no idea how loud it is but with Bedford being the strictest of tracks I'm a little nervous.  My previous car was a tin top so its very difficult to compare!  Appreciate that the only answer is to get it tested, but with it being in storage, battery disconnected etc that's not so easy.

 

The car is a 1.8 zetec on throttle bodies (but not protruding) with 160bhp.  The exhaust is a custom made exhaust.  Well made but not the biggest of silencers.  Pic below.

 

Do many zetecs of around this level of tune fail the noise test?  i.e. am I likely to be worrying about nothing (although, having not heard it, I get you can't comment on my cars noise levels!)?  

 

The alternative is to book somewhere like Cadwell for the first track day, but I'd prefer a track I've been to before with more run off - hence why Bedford.

 

 

 

I was at Bedford today.  98.1 static, but I got black flagged on the drive by.  To give the circuit some credit, I pinged one of the meters at 86.9db vs the 87.5 limit.  So they brought me in, showed my on the screens where the meter was that causing the issue, and then gave me some hints of how to drive past it so as not to cause an issue.

 

Whilst it is a pain that the limit is low, that's down to the council and not the circuit.  I think the circuit managed this well and were very helpful.

 

It was a great day, (well morning) right up until my feet started getting hot and wet!  The hose coming out of the expansion tank had split.  Managed to bodge it with some tape but it was a get me home fix, and not one I'd trust back on the track.  Still, can't grumble, it may be the last chance for track time for a while