Exhaust inserts for track days
Exhaust inserts for track days
Author
Discussion

orpheus

Original Poster:

31 posts

258 months

Monday 21st February 2005
quotequote all
Does anyone know of an insert for a 996 C2 standard exhaust that will knock a few db off the sound level?
I've got a baffle or two loose, and would rather pay tens of pounds for a 'bolt-on' to get it under the 98db Goodwood sound limit, rather than hundreds of pounds for a new exhaust...
I'm thinking of something along the lines of this:
www.daymotorsports.com/product/296/c/
(but suitably oval instead of round!)

lightweight

1,165 posts

272 months

Monday 21st February 2005
quotequote all
A standard 996 should easaly get past the goodwood static and will be fine on the drive by the only place that is dodgy is the driveby at the exit of the chicane and once my car is hot even with the sports exhaust is on loud it passes.

orpheus

Original Poster:

31 posts

258 months

Monday 21st February 2005
quotequote all
Well I had to drive away (dejectedly ) last time when I failed at 98db, so those loose baffles are obviously not doing me any favours. Seeing as it's not loud enough to fail an MOT (and actually sounds great to my ears) I'm hoping to avoid spending the £400 that the OPC has quoted to replace them...

Melv

4,708 posts

289 months

Monday 21st February 2005
quotequote all
Silencer tips available from Merlin at Castle Combe, about forty/fifty quid + VAT each.

But you will have to find old 996 tips to cut off flange and weld it on to new silencer, so you canbolt them on securely -there is no cheap option, I'm afraid.

By the time you've done all this, you might as well pick up a s/h unit.......Porsch-Apart -01706 824053

Mel

mrattley

12 posts

255 months

Monday 21st February 2005
quotequote all

Why not try Peter Tognola @ Tognola Engineering in Windsor. Tel 01753 545053. Peter has fixed me up with bolt-ons for my 993 T4 before at a very reasonable price. It easily passed the db checks at Goodwood and Castle Coombe.

Mark

lightweight

1,165 posts

272 months

Monday 21st February 2005
quotequote all
orpheus said:
Well I had to drive away (dejectedly ) last time when I failed at 98db, so those loose baffles are obviously not doing me any favours. Seeing as it's not loud enough to fail an MOT (and actually sounds great to my ears) I'm hoping to avoid spending the £400 that the OPC has quoted to replace them...


Sorry to hear that I think there is a nack to passing statics in a 911 as all the noise is at the back my method is to make sure the car is hot a good couple of runs up kennel hit works a treet for me then at the sound check point keep the windows closed depress the clutch and slownly build up to 4600rpm. your car must sound great

orpheus

Original Poster:

31 posts

258 months

Wednesday 2nd March 2005
quotequote all
I visited Tognola Engineering, but they (Greg) didn't think my car sounded that loud so advised I save my money. FYI - tips would work out at around £250 once modified and fitted.

I've since managed to get my car noise tested, and thought I'd post the results for you:
0.5 metres from one exhaust @ 45 degrees = 94.8db @ 5000rpm
@5250rpm (i.e. 3/4 of max revs) = 96.4db
@5250rpm but centrally (i.e. between the exhausts) = 97.9db (!)

Unfortunately, the weather and traffic prevented me from getting the car anywhere near hot before this testing, which hopefully means it'll be a couple of db quieter on the day, but either way it looks like I'm safe to go to Goodwood and was just the victim of an incorrectly calibrated meter last time.

BTW - the testing was done by Noico Ltd in Hook (M3 J5), and the chap there (Martin Ailing) said he'd be willing to test other cars for a nominal amount...

nigel911

20 posts

254 months

Tuesday 8th March 2005
quotequote all
Try talking to Goodwood direct. I run a couple of track days a year down there and the marshalls are very helpful (if you do not get really arsy with them). They have managed to source a bolt on falic looking device (I can not tink of the real name for now) which is filled with wire wool which will knock off upto 10dbs.

Good luck.

fergus

6,430 posts

299 months

Tuesday 8th March 2005
quotequote all
Also, see if you can hire a noise meter and do a drive by test, as the engine under load will be a lot louder than a static test. Most testers don't seem to recognise this fact. Monkeys!

fergus

6,430 posts

299 months

Tuesday 8th March 2005
quotequote all
Also, see if you can hire a noise meter and do a drive by test, as the engine under load will be a lot louder than a static test. Most testers don't seem to recognise this fact. Monkeys!

fergus

6,430 posts

299 months

Tuesday 8th March 2005
quotequote all
Also, see if you can hire a noise meter and do a drive by test, as the engine under load will be a lot louder than a static test. Most testers don't seem to recognise this fact. Monkeys!

ninemeister

1,146 posts

282 months

Tuesday 8th March 2005
quotequote all
But make sure that you test it three times to be sure of the reading.

GuyR

2,524 posts

306 months

Wednesday 9th March 2005
quotequote all

The drive-by tests are done much further away from the exhaust than the static test eg 10m+ vs 1m. Given sound diffussion over area, the dB numbers are not comparable. Drive-bys at each venue vary in location and this has a great effect on readings, so they cannot be duplicated. Even the surface makes a huge difference eg grass absorbs sound, tarmac reflects it.......

Guy

Buster44

487 posts

271 months

Wednesday 9th March 2005
quotequote all
Might be worth investing a few quid in a decibel meter. I purchased one a couple of years ago for around £60 and although not certificated I have found it pretty accurate.

There are some here (can't remember exactly where I got mine from):

www.quasarelectronics.com/ms637.htm

Melv

4,708 posts

289 months

Wednesday 9th March 2005
quotequote all
Fergus -your car is three times as loud?

Rgds
Mel