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Hey all,
As I get close to the 1500km break in mark I'm seeing (hearing) that the new car isn't as quiet as I thought it might be...I run at Tremblant and its a 92db track (seriously enforced). On my 991.2 GT3 I had deleted the side mufflers (soul) and had a Dundon quiet center muffler with their turn downs and passed most days with valves open. Cloudy days I would sometimes need to close the valves.
Does anyone have data on the new vs old GT3's in terms of DB's?
Dundon tells me that their old "loud" muffler and the stock 992 muffler (both on the 992) are quite similar...
Yeah. This is quite frustrating. Two things seem true to me.
1. These cars don't need to be this loud to make power. The S2000 was 120 hp/liter and wasn't this loud. Modern supercars are loud because of taste, not engineering.
2. Despite 1., it's not easy for the aftermarket to make an exhaust solution that is quieter, makes the same power, and can be packaged well in the space available without drone.
Not sure there will ever be a good solution, but if a company makes one, I'd be interested.
Oh boy...this isn't great news for us on restricted tracks. Mind you...the DB level will depend on how far away the mic was etc but still, it seems the 992's are a bit louder than the 991's.
Funny that we all thought that with the particulate filters it would cut the sound.
I'll be on track tomorrow with a small group and will have an idea what we are working with and may need to find a solution.
Oh boy...this isn't great news for us on restricted tracks. Mind you...the DB level will depend on how far away the mic was etc but still, it seems the 992's are a bit louder than the 991's.
Funny that we all thought that with the particulate filters it would cut the sound.
I'll be on track tomorrow with a small group and will have an idea what we are working with and may need to find a solution.
In my experience being on track alongside many 992 GT3s and tracking a 992 GT3, they don't seem louder than the 991. But I have no empirical evidence.
I've never measured my 3RS dB level. But I've never been flagged on track so I gotta assume it's lower than 103dB.
Last edited by FourT6and2; 05-04-2022 at 03:13 PM.
Oh boy...this isn't great news for us on restricted tracks. Mind you...the DB level will depend on how far away the mic was etc but still, it seems the 992's are a bit louder than the 991's.
Funny that we all thought that with the particulate filters it would cut the sound.
I'll be on track tomorrow with a small group and will have an idea what we are working with and may need to find a solution.
Where the mic is should be pretty standarized. I believe it's 50ft from the center point of the driving line or something but how far sound carries can vary widely simply if it's cloudy or or clear, windy or not etc.
We have a new track opening here (Rocky Mountain Motorsports) and this was their response to my question on sound management which I found insightful:
We have 2 sound monitoring stations (microphones) around the track. One around turn 4 (right side of track) and one around turn 16 (left side of track). These microphones are 15m (50ft) from the center point of the driving line. We will be able to use the GPS unit in each vehicle to record their sound at each station (therefore allowing us to determine which vehicles are over-contributing to the sound). The County bylaw states that we need to be at 65db or less on average per hour at the perimeter of the property. The sound monitoring system we have will take the sound readings from the trackside microphones, run it through an algorithm, and determine what our average sound level will be for the hour. The system will track our progress and estimate where we will be for the hour. If we are trending to be over, we will need to take measures to ensure that we are not over for the hour. These measures could include reducing the number of vehicles on track, increasing the time between run groups (no activity on track), or removing the excessively loud vehicles. What we cannot do is allow some excessively loud vehicles on track for half an hour and then not use the track for the remaining half hour as this isn’t in the spirit of the bylaw. The sound modeling we’ve had done indicates that the trackside sound limit will be 95db, BUT this is what we need to verify with our sound testing.
Would love to hear how the 992 GT3 performed at LCMP in terms of sound levels.
I’m running in a 2 day event end of month, and likewise concerned about noise levels.
Last week my car failed the sound check @ Calabogie Motorsport Park (5000rpm, exhaust open, approx 20 ft from rear @ 104db), and it took some creative throttle technique and exhaust closed to finally pass @ 98 db.
Car is still in break-in period, so shifting below 7000rpm, and assuming it will only get louder once I can rev to 9k redline.
Oh boy...this isn't great news for us on restricted tracks. Mind you...the DB level will depend on how far away the mic was etc but still, it seems the 992's are a bit louder than the 991's.
Funny that we all thought that with the particulate filters it would cut the sound.
I'll be on track tomorrow with a small group and will have an idea what we are working with and may need to find a solution.
So how did it go? Are we going to have an issue with our GT3's?
Would love to hear how the 992 GT3 performed at LCMP in terms of sound levels.
I’m running in a 2 day event end of month, and likewise concerned about noise levels.
Last week my car failed the sound check @ Calabogie Motorsport Park (5000rpm, exhaust open, approx 20 ft from rear @ 104db), and it took some creative throttle technique and exhaust closed to finally pass @ 98 db.
Car is still in break-in period, so shifting below 7000rpm, and assuming it will only get louder once I can rev to 9k redline.
Very concerned about a black flag at LCMT…
Hate to break it to you but if you failed Calabogie sound check which is very very permissive, you're toast at Tremblant. They are very strict with sound there.
Yeah. This is quite frustrating. Two things seem true to me.
1. These cars don't need to be this loud to make power. The S2000 was 120 hp/liter and wasn't this loud. Modern supercars are loud because of taste, not engineering.
2. Despite 1., it's not easy for the aftermarket to make an exhaust solution that is quieter, makes the same power, and can be packaged well in the space available without drone.
Not sure there will ever be a good solution, but if a company makes one, I'd be interested.
And it seems like we're not getting closer to a solution with the new valve setup on the 992. I wonder if restricting the exhaust enough to pass sound restrictions does affect the way these motors run? I remember when Josh Golden was running a supertrapp sweep contraption on his GT3 Paul Savvedra (who was running the shop at MONTEREY PORSCHE at the time) told me the car never ran right at laguna with the exhaust restricted that much. He always thought restricting the GT3 exhaust for more than a short period at high RPMs wasn't good. I know that Dundon claims no power loss with their quiet but I've never talked to anyone who actually run that muffler long term. The problem is probably economics everyone wants a louder exhaust not something that will run 90db at 9K.
05-02-2022, 10:02 PM
992 GT3 on "quiet" tracks...
