Barty964rst

Guys

Have just been measured for my noise level at Oulton Park and need to lose 5db.
Does anyone know where I van obtain a bolt on baffle for a standard oval 964 exhaust tip? I need a fix for Spa in less than two weeks?
Thanks for any pointers or Tips.

boxsey911

Simon, I don't think you can get anything to bolt in to the standard exhaust tip. You need to buy a round tip. You can get one here:

http://www.design911.co.uk/fu/pt63_4...93/Tail-Pipes/

These will use the same clamp and olive that is on your standard tip (so nothing extra to buy). You could buy their version that has an insert which should reduce you down by 2 or 3 db (see same link above). Alternatively you could just by a tip and also buy a decibel devil to bolt in:

http://www.decibeldevil.co.uk/content/fitting

With the latter you could take it with you and just bolt it in if you fail noise. The Devils are about £70 each. BTW you have to be extremely noisy to fail Spa. They only come and test you if they think you are too noisy when going round the track.

ras62

Decibel devil will reduce the noise but not by 5dB, maybe 2-3dB. You dont say what exhaust configuration you are running now but maybe a cat bypass silencer would work, it knocked 3-4dB off my car.
Did not realise Spa was noise sensitive like the UK...

Rephlex

I have just had a cat delete and cup pipe fitted by Nine Excellence who have developed their own system with an exhaust fabricator.

They are now considering adding a variation of the switchable type of system the supply for 996 and 997s, with a long silencer alongside the cup pipe and a control in the cabin to switch between open and silenced modes.

I haven't got my car back yet so don't know quite how loud it is going to be, but will be watching this development.

My car;

h_____

Simon,

Can you not just get a standard rear box? If you've got a cat bypass and standard 2nd silencer and standard rear box you should be well under 105. I got a rear box for 50quid second hand. Seemed like the most sensible way to go.

I've just looked there are couple on Ebay for 250 buy it now.....I picked up a bargain then. Otherwise I'd ring a couple of indies see if they have one. I am assuming you didnt have a full back box.

cheers

bigunit_271078

Given my issues at oulton on Friday getting on I just bought the rear silencer from rpm on ebay (£250). Least if I carry it with me I have a definite solution. The rear box that 9m lent me took Dbs from 109 to under 100. I think he wanted between £500-1000 for it as it was off his RS. I hate how the 964 sounds with the silencer on though

I checked Spa and its 107 static and on track. Last year there was no test before we went on track and not think anyone got questioned during the day.

Cheeksyboy

I had a DD at Oulton last year and it took me from 108 to 103.

It's a bit used (packing burnt away), but I'll pack it for Spa just in case someone needs it, maybe knock a couple of db off.

Having said that, no 964s were checked at Spa last year (unlike the 'ring) and there were many things plenty louder that were going round.....I was about 107db that time last year and didn't have noise problems....just well documented wheel problems!

HiWind

search on the cup forum - lots of alternatives there, not least of all is the 90 degree turn down/away
tactically aimed away from the guy with the sound meter (usually toward the end of the straight )

Barty964rst

Guys,
Thanks for your suggestions and options on the noise matter. I will take a look to see what set up I have on the car. It does seem strange as on Friday from the pitt wall observiers said my car was not that loud compared to others out on the track! Will let you know the final fix!

Cheeksyboy

Did you have gold bbs on yours on Friday? If you did, wish I'd said hello!

h_____

Simon - I agree, the car didnt seem that loud!!

bigunit_271078

The black 3.2 carrera was mega loud. How it passed the static test I have no idea

Marc Shaw

Below is a shot of my not-so-subtle turn away pipes topped with SuperTrapp mufflers to pass sound at Laguna Seca in California (this combo dropped me from 103 to 89 db). Can you guess which side of the track the sound station is on?

I have also tried CarChemistry inserts, they dropped sound by about 5-6 db but the car did feel more choked and down on power.

Induction noise (not just exhaust noise) can be an issue too so I know some racers stuff the intake/air box with foam to reduce sound too.

Marc

freedman

If anyone needs a factory primary silencer I've got a spare

Barty964rst

I did, and that was me. I must admit I caught up with a lot of people I hadn't seen for a while and I didn't get to say high to the other 994 guys. Still Spa will be here soon!