997.1 GT3 exhaust noise levels

[Trev450]

I'm giving some serious consideration to puchasing one of these at some point in either clubsport or RS form, and since it is to spend most of its time on track, I am very eager to know the noise levels the stock exhaust system emits.

Can anyone who has had experience of tracking one of these give me some idea of the db rating, and if you have been refused at any circuits, which ones, by how much over the limit where you, and what, if anything, did you do about it?

[ttdan]

you need to stick to 105db track days, then you'll be ok. Standard car is 101-102 ish static at 75% revs.

[keep it lit]

ttdan said:

you need to stick to 105db track days, then you'll be ok. Standard car is 101-102 ish static at 75% revs.

as said above your only option will be 105 days.. but I have seen a few std system 997's fail noise tests at Oulton & Donington recently, they do seem to be slightly louder than STD 996's.. as with all gt3's, the loudness escalates with the mileage on the original standard systems.. a solution would be to make the rear silencer box on the 997 re-packable, this could be done.

[pete]

One option to temporarily quieten the 997 is to pull the vacuum pipe from the solenoid that controls the exhaust valves. It has the opposite effect to the popular trick of unplugging the solenoid to open the valves all the time; rather it keeps the valves shut even at high revs and wide open throttle. By all accounts you lose a bit of torque and top end power, but it could keep you on track somewhere like Oulton.

The instructions are on the Sharkwerks site, I think.

Cheers,
Pete

[Trev450]

ttdan said:

you need to stick to 105db track days, then you'll be ok. Standard car is 101-102 ish static at 75% revs.

That is quite loud. My old bike-engined single seater wasn't much more than that and that would rev to 13000 rpm.

Some good advice though - many thanks.

[DiscoColin]

Trev450 said:

ttdan said:

you need to stick to 105db track days, then you'll be ok. Standard car is 101-102 ish static at 75% revs.

That is quite loud. My old bike-engined single seater wasn't much more than that and that would rev to 13000 rpm.

Some good advice though - many thanks.

As I said on another thread - with 911s the problem stems from MSV's static noise measuring test having the meter a foot away from the engine. What I would like to know, however, is whether anyone has tried the Cargraphic silenced tips and whether that takes enough noise out of the equation to pass a 101? [I am of course particularly interested from the point of view of a 3.8]...

If they work as advertised then this spendy little enhancement ought to do the job? http://www.cargraphic.de/index.php?/s,6,7,18,5135,...

[ttdan]

I've got on at Bedford's 101db days before. Two GT3's together on the track has caused problems but apart from that it was fine. The exhaust valve open defeat trick could always be used as a contingency plan.

[Callughan]

101db days are ok if plugged in

[DiscoColin]

Callughan said:

101db days are ok if plugged in

Not always. When I was turned away at a 101db day at Snetterton in a 996, so were the 997s (indeed all 911s that showed up, and this was only the month after having had no trouble at a 101 day at Brands withe the same TDO). MSV tests are not consistent and to some extent depend upon how the testers feel on the day and whether they have someone stick their head through your window to confirm that you are giving them over 6k on the dial. I'll not be chancing it again anyway - they refused to do a drive by test and were completely inflexible.

[Callughan]

DiscoColin said:

Callughan said:

101db days are ok if plugged in

Not always. When I was turned away at a 101db day at Snetterton in a 996, so were the 997s (indeed all 911s that showed up, and this was only the month after having had no trouble at a 101 day at Brands withe the same TDO). MSV tests are not consistent and to some extent depend upon how the testers feel on the day and whether they have someone stick their head through your window to confirm that you are giving them over 6k on the dial. I'll not be chancing it again anyway - they refused to do a drive by test and were completely inflexible.

Sorry to hear that, they're usually ok at Bedford

[nsm3]

I'm guessing this one wouldn't get on any track day in the UK? Sounds right though !

http://www.gtspirit.com/2011/06/25/video-onboard-p...

Not quite on topic, but I thought it more interesting than the "how much has my car lost in the last half hour" threads?

Edited by nsm3 on Sunday 8th January 07:24

[Trev450]

nsm3 said:

I'm guessing this one wouldn't get on any track day in the UK? Sounds right though !

http://www.gtspirit.com/2011/06/25/video-onboard-p...

Not quite on topic, but I thought it more interesting than the "how much has my car lost in the last half hour" threads?

Edited by nsm3 on Sunday 8th January 07:24

I love the fact that he's wearing nomex gloves and shorts wtf!!

Does sound good though.

[Skittles001]

pete said:

One option to temporarily quieten the 997 is to pull the vacuum pipe from the solenoid that controls the exhaust valves. It has the opposite effect to the popular trick of unplugging the solenoid to open the valves all the time; rather it keeps the valves shut even at high revs and wide open throttle. By all accounts you lose a bit of torque and top end power, but it could keep you on track somewhere like Oulton.

The instructions are on the Sharkwerks site, I think.

Cheers,
Pete

This. Costs 10p and takes 5 seconds.

[ttdan]

nsm3 said:

I'm guessing this one wouldn't get on any track day in the UK? Sounds right though !

http://www.gtspirit.com/2011/06/25/video-onboard-p...

Not quite on topic, but I thought it more interesting than the "how much has my car lost in the last half hour" threads?

Edited by nsm3 on Sunday 8th January 07:24

sounds pretty awesome! Imola looks great too.

I fancy an x pipe (sharkwerks, FVD or RSS) but not sure if it will still remain in the sub 105db window, none of the manufacturers will state any noise levels (all the pipes are virtually identical so I imagine they all have a similar effect on sound level)

[keep it lit]

we fitted a sharkwerks x-pipe (rear silencer by-pass) with titanium tips yesterday to a 3.8rs.. now sounds awesome, like a scuderia!!.. but sadly no way trackday friendly!!

ttdan said:

sounds pretty awesome! Imola looks great too.

I fancy an x pipe (sharkwerks, FVD or RSS) but not sure if it will still remain in the sub 105db window, none of the manufacturers will state any noise levels (all the pipes are virtually identical so I imagine they all have a similar effect on sound level)

[ttdan]

keep it lit said:

we fitted a sharkwerks x-pipe (rear silencer by-pass) with titanium tips yesterday to a 3.8rs.. now sounds awesome, like a scuderia!!.. but sadly no way trackday friendly!!

shame you didn't measure the sound level!

[DiscoColin]

Skittles001 said:

pete said:

One option to temporarily quieten the 997 is to pull the vacuum pipe from the solenoid that controls the exhaust valves. It has the opposite effect to the popular trick of unplugging the solenoid to open the valves all the time; rather it keeps the valves shut even at high revs and wide open throttle. By all accounts you lose a bit of torque and top end power, but it could keep you on track somewhere like Oulton.

The instructions are on the Sharkwerks site, I think.

Cheers,
Pete

This. Costs 10p and takes 5 seconds.

Found it - http://sharkwerks.com/porsche/technical-articles/1...
Certainly seems worth looking into to beat the static.

[keep it lit]

ttdan said:

shame you didn't measure the sound level!

definitely louder than the 6rs wearing a full cargraphic which blew 108db at oulton... at a guess 110db.

[tomvcarter]

I have an Akrapovic Evolution on mine and it read 102 with the Sport button off. Never tried it with it on, but its loud when you want it to be!

[911Thrasher]

I track my 7.1RS regularly at Bedford, and never experienced a problem - even though they are really stringent.

Indeed they ask 75% rev static (101dB), but I usually stick it to 5000rpm and all good at roughly 98/99 dB
Drive by is no problem.