911 Turbo too noisey

[andyscoobs]

I have a 996TT with a Fabspeed exhaust. I knew this would be louder but the old one was too tame.
I measured the db's on it the other day and it read about 104 - 105 db's. This seemed quite high as it doesn't sound that loud when driving around.
I've read on other posts that 911's suffer on static tests due to engine and induction noise.
I really like bedford so I need to get it down to 101db's.
Hayward and Scott said they could make some 12" silencers that would bolt on the tips and reduce the sound. But couldn't say 100% it would reduce it enough, as I said I wanted it down to 98db's.

Putting the old exhaust back on isn't an option as it's a sh*t of a job.

Any thoughts ?

Cheers

Andy

[Brett928S2]

Hi

Those cans to add to exhaust will only drop your Dbs by around 5 db and if your testing was done at idle , then at 3/4 revs it will be well over 115 db

You need to test at 3/4 revs at 18 inches from the exhaust tips and level with the ground....and on hard standing NOT grass...

All the best Brett

[andyscoobs]

Brett928S2 said:

Hi

Those cans to add to exhaust will only drop your Dbs by around 5 db and if your testing was done at idle , then at 3/4 revs it will be well over 115 db

You need to test at 3/4 revs at 18 inches from the exhaust tips and level with the ground....and on hard standing NOT grass...

All the best Brett

Sorry. Should have put that the revs were 3/4 and the 105db reading was on a flat solid surface.

[Porkie]

I have a 996TT with DMS remap and a Milltek exhaust and its done 3 whole days at Bedford this year already and only failed once... sadly you get no second chances now But I am still gonna go back with it in few months... I think it was an unlucky gust of wind myself!

its driveby that matters at Bedford. You can fail the static by as much as you want and still get a chance on track.

My Boxster always fails idle with its H&S exhaust.... but is fine on track for example

good luck with what ever you choose to do. Great place Bedford! Love it!

Edited by Porkie on Friday 11th April 14:48

Edited by Porkie on Friday 11th April 14:49

[wildoliver]

In theory while it would look ridiculous making a pair of flat plates mounted above the tailpies to direct the noise and gasses downwards would not offer enough resistance to reduce power but would direct a large amount of sound in to the ground where it would not trigger drive by meters, to avoid triggering them you basically want to make sure at no point can the muzzle of the exhaust pipe point at the sensors, so even dtm style upswept tips would probably work.

[andyscoobs]

With the Fabspeed exhaust you can redirect your end pipes towards the floor.
Would this lose me some db's and would I get away with it at a track ?

[B19TOY]

Hi Andyscoobs

My GT2 plus Fabspeed tests at 103-105. I would be interested if you find an effective solution to knock off 5db or so without increasing back pressure.

[andyscoobs]

I'm going to test it with the pipes facing downwards. See how much thats reduces it. If it's still too loud I will fit the Hayward and Scott silencers and go from there.
I will post my results

[B19TOY]

andyscoobs said:

I'm going to test it with the pipes facing downwards. See how much thats reduces it. If it's still too loud I will fit the Hayward and Scott silencers and go from there.
I will post my results

Any news from trying the downward pipes?

[andyscoobs]

Not yet mate. Will let u know