Can a stock exhaust .2RS pass 92dB at Laguna Seca without the exhaust bypass mod?
03-10-2013, 02:38 PM
#1
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Thread Starter
Can a stock exhaust .2RS pass 92dB at Laguna Seca without the exhaust bypass mod?
Guys-- I've searched the archives and am aware of Mikyu's exhaust valve mod, but I'm wondering if anyone has first hand experience whether a stock .2RS will pass sound on a 92dB day at LS WITHOUT capping the valve.
And is the sound station still between turns 5 and 6, or is there a rover now too? I haven't been down in a few years....
And is the sound station still between turns 5 and 6, or is there a rover now too? I haven't been down in a few years....
03-10-2013, 09:31 PM
#3
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yes, no, maybe, mostly no - depends, but biased towards no - my Stock 11 GT3 997.2 is right on the line - I wire the exhaust valves shut and so far so good, but it's iffy…
03-10-2013, 10:18 PM
#6
There's more to read as you check back over old threads on Laguna sound.
The short answer is to get a set of turnips from Sharkwerks. A 5 min job to bolt on with a 13mm ratchet wrench. No mods to the car.
There's a (rare) 105dB Sunday on the 31st with CFRA and they are inviting guests (of members) to wait list.
The 997.2 RS 3.8 won't pass sound at wide open throttle uphill out of T5 past the sound check mic.
Staying left isn't enough.
"Lift n shift" (up to 4th) is the only way to "make" sound unmodified. It costs about 1 sec, just resume at the bridge.
Going up the hill with another similar 911 can make things worse with the exhausts resonating.
Low clouds (even scattered cloud) can increase dB at the mic.
Avoiding getting the first meatball is important to avoid being targeted.
The first session of the day and the first session after lunch tend to be when they check.
There is a mobile "roving" sound check unit.
Some say the mobile check can be either side of the track, some say it's only on the outside, which makes sense with the intent of measuring noise levels relevant to "neighbors."
Plugging the valves will cost considerable mid-range torque.
The electric valve "plug" will also cost mid-range torque.
The only "solution" is a switch in the cabin that will bypass the side valves, then the driver switches back after climbing the hill. This retains the full power and torque curve. You can buy parts over the counter for the connectors so there's no cutting or wire taps, etc.
Using a new "External Symposer," weighing a mere 30 lbs and suspended on a composite carbon fiber trellis frame extending six feet behind the car, costing only $3000 as an option, Porsche assures use the 991 GT3 will pass sound.
The short answer is to get a set of turnips from Sharkwerks. A 5 min job to bolt on with a 13mm ratchet wrench. No mods to the car.
There's a (rare) 105dB Sunday on the 31st with CFRA and they are inviting guests (of members) to wait list.
The 997.2 RS 3.8 won't pass sound at wide open throttle uphill out of T5 past the sound check mic.
Staying left isn't enough.
"Lift n shift" (up to 4th) is the only way to "make" sound unmodified. It costs about 1 sec, just resume at the bridge.
Going up the hill with another similar 911 can make things worse with the exhausts resonating.
Low clouds (even scattered cloud) can increase dB at the mic.
Avoiding getting the first meatball is important to avoid being targeted.
The first session of the day and the first session after lunch tend to be when they check.
There is a mobile "roving" sound check unit.
Some say the mobile check can be either side of the track, some say it's only on the outside, which makes sense with the intent of measuring noise levels relevant to "neighbors."
Plugging the valves will cost considerable mid-range torque.
The electric valve "plug" will also cost mid-range torque.
The only "solution" is a switch in the cabin that will bypass the side valves, then the driver switches back after climbing the hill. This retains the full power and torque curve. You can buy parts over the counter for the connectors so there's no cutting or wire taps, etc.
Using a new "External Symposer," weighing a mere 30 lbs and suspended on a composite carbon fiber trellis frame extending six feet behind the car, costing only $3000 as an option, Porsche assures use the 991 GT3 will pass sound.
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03-11-2013, 12:22 AM
#8
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Stock GT3 RS will not pass at Laguna Seca, I know first hand. I got meat balled for simply having the the SharkWerx exhaust pipes--crazy. They now have a roving sound meter as well. Unless it's a 103db day, it's not worth taking your car to Laguna Seca. If you want to run 5/10ths at 2k-3k rpms, you can probably squeeze by, but what's the point. It's a shame the local residents have ruined it for us track guys--especially considering the track was there long before they purchased their homes.
03-11-2013, 12:32 AM
#9
Stock GT3 RS will not pass at Laguna Seca, I know first hand. I got meat balled for simply having the the SharkWerx exhaust pipes--crazy. They now have a roving sound meter as well. Unless it's a 103db day, it's not worth taking your car to Laguna Seca. If you want to run 5/10ths at 2k-3k rpms, you can probably squeeze by, but what's the point. It's a shame the local residents have ruined it for us track guys--especially considering the track was there long before they purchased their homes.
03-11-2013, 12:41 AM
#10
I was at a Trackmaster's day on March 2nd and there were lots of very creative exhaust solutions on display. Most routed the exhaust to the inside of the track (driver's left) as the 'sound lady" is on the outside between turns 5 and 6 and nobody was sent home for having exhaust sculpture on the back of their cars.
So, I agree with the majority of folks that you will not pass stock, but you should not have a problem with bolting on a solution of some sort.
So, I agree with the majority of folks that you will not pass stock, but you should not have a problem with bolting on a solution of some sort.
03-11-2013, 12:51 AM
#13
Rennlist Member
mikymu has a thread on here. With a sharkwerks center bypass I did not have a problem on a 92 db day.
It is a simple 2 minute fix with the right vacumm plug.
But yes I was there on the 4th and they are active in 5 and 6.
It is a simple 2 minute fix with the right vacumm plug.
But yes I was there on the 4th and they are active in 5 and 6.
03-11-2013, 02:02 AM
#15
I ran there on March 1st and had no problems with Sharkwerks bypass, electronic muffler switch, and AWE Tuning turn down pipes angled to the inside. I have used the AWE turn down pipes for several years with no noise problems.
http://www.awe-tuning.com/awe-997gt3tipkit
http://www.awe-tuning.com/awe-997gt3tipkit