Noise Limits - Track Day

Technical Advice, Faults and How-To Information.
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Deleted User 3412

Post by Deleted User 3412 »

I’ve searched but can’t find an answer to this.
Does anyone know the noise output on a standard V6 340 if taken on a track?
The test is the usual 0.5m away at 3/4 revs.
Booked in at thruxton who have a very strict and quite restrictive 90db.
Clearly it would make sense to keep valves shut but I’m worried as a noisy beast that it might fail which would be a long and wasted trip!
Thank you in advance

Derivative
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Post by Derivative »

90db has to be the worst in the country?
I think the valves are going to be open at 3/4 revs and at 90db I would have guessed it would likely fail even if the valves were closed.
Does the ECU let you rev it to 3/4 in neutral? (My Mercedes would restrict the revs if not in drive.)

(I got sent home with my tail betwen my legs when my Ducati failed at Castle Combe which was 105db i.e. more than 3 times as noisy as 90db).
It was widely known that some road legal bikes (properly stamped exhaust - not aftermarket) would fail circuit test noise rules. You could drive round all the roads to the circuit legally but be too noisy for the track when you got there!
MY2018 R-Dynamic 340 coupe
simpleR
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Post by simpleR »

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Deleted User 3412

Post by Deleted User 3412 »

simpleR wrote: Wed Jul 14, 2021 4:00 pm This might help?
viewtopic.php?t=3567&start=10#p33196
Thanks simpleR. Interesting read, can’t quite believe the science that sits behind this. Doesn’t quite give me the info I need.
I’ve found a sound measuring app that claims to do this so I’ll give it a go (somewhere quieter away from neighbours!!) and post results. Might be useful for someone else In future.
Deleted User 3412

Post by Deleted User 3412 »

Derivative wrote: Wed Jul 14, 2021 2:21 pm 90db has to be the worst in the country?
I think the valves are going to be open at 3/4 revs and at 90db I would have guessed it would likely fail even if the valves were closed.
Does the ECU let you rev it to 3/4 in neutral? (My Mercedes would restrict the revs if not in drive.)
Crazy, isn’t it!
I know it revs freely in neutral sadly, maybe I’ll have to do half throttle and claim it as 3/4 ;)
MANTOT3
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Post by MANTOT3 »

No definative answer for you but think you'll be safe.
I’m sure someone will have done this before, had they failed the noise test I’m sure it would be out there in a forum or social media post and we’d all know it’s a problem.
Not sure about the 340 v6 but, my V8 won’t free rev over 4000rpm in neutral so your valves will stay closed hopefully, this is for protection of the gearbox more than your ears!
Was going to say, mine passed noise test at Castle Combe for a track day, I thought it was 90DB but will stand corrected having read Derivatives post.
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Deleted User 3412

Post by Deleted User 3412 »

MANTOT3 wrote: Wed Jul 14, 2021 10:12 pm Not sure about the 340 v6 but, my V8 won’t free rev over 4000rpm in neutral so your valves will stay closed hopefully, this is for protection of the gearbox more than your ears!
I’ll give the sound test a go and ask motorsport events specifically if they’ve had problems with f types in the past but I hope you’re right.
Appreciate the reply on the subject 👍
scharlton
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Post by scharlton »

I would suggest watching a few youtube clips such as "How to drive Thruxton - onboard narrated lap with Sam Hancock" before going.

Looks like a challenging track for road position. Hope you get past sound testing. Enjoy.
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Deleted User 3412

Post by Deleted User 3412 »

scharlton wrote: Thu Jul 15, 2021 8:21 am I would suggest watching a few youtube clips such as "How to drive Thruxton - onboard narrated lap with Sam Hancock" before going.

Looks like a challenging track for road position. Hope you get past sound testing. Enjoy.
As it happens I did watch some videos yesterday, but thanks for the advice! Having spectated at thruxton it’s a quick track and you need to know the lines.

I’m sure someone here must have been to thruxton on a track day? V5 states static db rating of 95db. How exactly this is measured I’ve no idea.

Time for some sound testing.
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