Track day noise

[Prizam]

My Chim has a sleeved exhaust and no pre-cats.

I want to do a track day or two in the spring / summer but im worried about the noise.

Anyone know how loud it should be?

Are those phone apps that measure Db accurate?

[locodude]

Depends which tracks you intend to use. The noise limits also vary at different times. Other than a very few 'unlimited' days the maximum you can expect to get away with is 105db. If you can get to a track day close to you they'll normally test it for you for free. My Chim' is bog std apart from no pre-cats and read 97db at Cadwell last year.

[phazed]

Agree on the standard being 97 or there abouts.

Expect a standard system being tested at 4.5k with no cats just about to scrape under the 100db limit that a lot of tracks have.

If you are thinking about doing Bedford in March,

http://www.pistonheads.com/xforums/topic.asp?h=0&a...

Which is actually the 16th! I will be taking 2 pairs of clamp on cans that really work.

[TV8]

Not sure where you are in the south east but if is not to far give Brands hatch a call and ask when it would be convinient for a noise test. They did that for me with a couple of phone calls in advance to agree date and then on the day.

[Quietlybonkers]

+1 Snetterton offered the same for me.

My stanrdard 4.0 Chim passed the test at Cadwell at 90db at 3750rpm. Managed to persuade them I woudn't be going above 5000. Assuming they insist on the low 4000s rpm, I would guess low to mid 90s dB. When you do go for the test at the start of your T/D, warm the car up and gently increase the revs to the level they tell you (normally 3/4 of max revs). I think my Chim's limiter is set at 6500, but when i found the limter in second gear, I was too busy looking at the truck coming the other way to notce the rpm! For heaven's sake try to get away with as low revs as possible.

[Chimjunkie]

Trackday noise is measured using the dBA scale. Most off the shelf meters measure dBC. dBA is much less sensitive to bass.

[Graham]

My catless but stock exhaust was 99db

[phazed]

Graham said:

My catless but stock exhaust was 99db

Mine at Combe was 99.9!

[jamienshelly]

I was curious as to how loud ours is with pre cats out and sleeved, so downloaded an app and had 113 db at idle (I think not) and did not register at 4000rpm. So i would say they are not accurate.
So I still dont know. I will get it tested at Neil Garners in March.

[Quietlybonkers]

jamienshelly said:

I was curious as to how loud ours is with pre cats out and sleeved, so downloaded an app and had 113 db at idle (I think not) and did not register at 4000rpm. So i would say they are not accurate.
So I still dont know. I will get it tested at Neil Garners in March.

Jamie, try calling Brands Hatch (or MSV, who are based at Brands - 01474 872331) and see if they can fit you in at a mutually convenient time for a sound test. Many circuits will do that, as they know you cannot safely book their track days unless you know your sound output.

[jamienshelly]

Cheers QB
Will be up that way soon, so I'll pre book and get it done then post back result.
I know its loud but it will be nice to know exactly how loud!

[blujay10]

And also remember that some circuits measure the noise at various points around the circuit (eg Goodwood - maybe they all do) That said mine is pretty standard and read 98 at Goodwood last year.

[phazed]

How you sleeved guys can stand the noise, my fully decatted is loud enough!

Ah, I know why, you can't hear your partners voice hence can't hear about the bathroom that wants decorating or the leaky tap...................

[jamienshelly]

phazed said:

How you sleeved guys can stand the noise, my fully decatted is loud enough!

Ah, I know why, you can't hear your partners voice hence can't hear about the bathroom that wants decorating or the leaky tap...................

Its not that bad, as the noise is behind you at 70(ish) and its glorious when you stand on the loud pedal

[Quietlybonkers]

jamienshelly said:

.............and its glorious when you stand on the loud pedal

Mine stays on the track better if I stay seated above 70 mph......

[BlackpoolRock]

Mine is fully sleeved and pre-cats out. Unless it's an unsilenced event (I dont think any trackday's do these) I highly doubt you'll pass the noise test with that exhaust setup. Your cheapest option is probably to keep your eyes open for a standard system (usually around £100 - £130) and just put that on for track days.

[SILICONEKID350HP]

Prizam said:

My Chim has a sleeved exhaust and no pre-cats.

I want to do a track day or two in the spring / summer but im worried about the noise.

Anyone know how loud it should be?

Are those phone apps that measure Db accurate?

Buy are pair of these just incase.

[Prizam]

I guess i need to get my self down to Silverstone and see just how loud the loud peddle is.

Got a link for those track day silencers?

[phazed]

Try ACT.

[wuckfitracing]

Try fleabay for bolt in silencers, I bought a couple for mine and they simply self tap in. I did a trackday in December but didnt need them at Donington, Took them just in case as not being able to play and not receiving a refund would have been bad.