Noise limits porsche 997.2S

Noise limits porsche 997.2S

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Discussion

vfb86

Original Poster:

10 posts

29 months

Wednesday 19th May
quotequote all
Hi All,
I signed up for a track day at Snetterton (first time ever) with MSV.

For Friday the limits are:
Static 105db
drive by: 92db

I'm just a bit worried my car wont make the test. I dont really wanna book instructor time and loose not only the ticket, but also the instructor's costs

Has anybody driven/ measured a 997 Gen 2 CS2 and what were your results? Should I be worried?

Many thanks

brillomaster

620 posts

137 months

Wednesday 19th May
quotequote all
Have you modified your exhaust in any way? Does it have switchable sports mode? Still got the cats on?

If you have a standard exhaust, it'll be fine. 105db static is pretty loud. I had an old 300zx, decatted with race mufflers on. It was loud enough to wake the dead, but that only managed 99db static when tested.

vfb86

Original Poster:

10 posts

29 months

Wednesday 19th May
quotequote all
car has no modifications

It has a sport/ sports plus mode, but no sports exhaust (PSE)

what are cats? Catalyst? Not sure, it's just a "standard" unmodified 911 (997.2 CS2)

Edit: Will let you know the results afterwards

Edited by vfb86 on Wednesday 19th May 15:35


Edited by vfb86 on Wednesday 19th May 15:36

braddo

7,743 posts

155 months

Wednesday 19th May
quotequote all
You'll be fine (or at least, I'll be amazed if you're not biggrin ).

The 997 GT3s are around 103-105 static and that's with exhaust valves open at around 6000 rpm (8400 redline).

911s tend to do well on drive-by noise because of the rear engine and not much induction noise ahead of the car. Compared to a hot hatch on throttle bodies they're very quiet!

nickfrog

14,663 posts

184 months

Wednesday 19th May
quotequote all
As others have said, it'll be fine. If you have a MSV venue near you they normally do noise testing FOC although not sure with Covid etc...

vfb86

Original Poster:

10 posts

29 months

Friday 21st May
quotequote all
Thanks all
Result: 103db with 997.2 (2010) CS2 rpm@5,500 ish

Ekona

1,597 posts

169 months

Friday 21st May
quotequote all
That seems extraordinarily high, I'm sure when I tracked my old 997.2 C2S with PSE I wasn't anywhere near that, certainly still in the 90's dB for the static. Given that the day in question was at Bedford which has limits of 101dB for the static, if mine had made the volume yours did I wouldn't have been allowed on and they're quite well known for being strict at Bedford.

Just goes to show how much a measurement can differ between tracks.

vfb86

Original Poster:

10 posts

29 months

Sunday 30th May
quotequote all
Well... I didn’t check the measurement myself, but that‘s what I‘ve been told.

I would say the microphone was likely rather <50cm than 50-100cm away from the exhaust, and I rev‘ed it up perhaps a bit too quick than you would ideally to get a lower db measurement

240Cup

347 posts

157 months

Monday 31st May
quotequote all
991.1 C2S with PSE (valves closed) was 98db on Friday with MSE at 4,500 rpm

PGNSagaris

2,542 posts

133 months

Monday 31st May
quotequote all
vfb86 said:
Hi All,
I signed up for a track day at Snetterton (first time ever) with MSV.

For Friday the limits are:
Static 105db
drive by: 92db

I'm just a bit worried my car wont make the test. I dont really wanna book instructor time and loose not only the ticket, but also the instructor's costs

Has anybody driven/ measured a 997 Gen 2 CS2 and what were your results? Should I be worried?

Many thanks
You’ll find it gets to 100db. Won’t be a problem. Enjoy the day, it’s a goodie Snetterton

phazed

19,789 posts

171 months

Saturday 26th June
quotequote all
vfb86 said:
Thanks all
Result: 103db with 997.2 (2010) CS2 rpm@5,500 ish
You were too high, (revs). You must raise the revs very slowly so you don't pass their rev point of measure.

That was critical in my old 5.5 TVR. A couple of hundred revs over the figure would mean a fail.....

I did Combe a couple of weeks ago. 997.1 with sports mode.

4.5K revs, 90db
With sports mode, 94db