When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Yes, aftermarket valved side mufflers will still do something with the gps box. Complete deletion of the side mufflers means the gps box is connected to nothing
My bad, I meant valved side deletes. My point in that post was eliminating the OEM side mufflers for valved side deletes (even with GPS control) takes away the major source of sound control. Looking at the cross section of the side mufflers John Gaydos posted a while back it's easy to see why they are so effective.
it's worth noting the dundon center muffler has been tested with a '15 GT3 @ laguna with side deletes and passed sound at a 92 db day.
Side deletes with a Dundon center is very appealing from a weight standpoint but I personally don't want to run a system that's quieter then OEM all the time.
You loose some of the effectiveness of the GPS when you're running side deletes. The OEM side mufflers do most of the heavy lifting deadening sound in the OEM system. As much as I too want to get rid of the side mufflers on my car for the heat/weight advantages that setup: Soul valved side deletes with GPS / OEM center / Soul silenced turn down tips, was the worst I tried sound wise.
This is kind of telling - will be curios once the testing with JCR is complete if this setup (valved side deletes + OEM Center + JCR silenced turn down tips) would pass. If that passes then no need for GPS and only need a wrench to swap the tips in and out for when at laguna. But, the tips will have to cut some serious sound to make this a reality.
I think a few people misread my earlier post, so hopefully this helps.
These are the tips I had on my car along with Track Nanny GPS when I blew a 95 with valved side deletes and an OEM center muffler. I feel like I'm raining on everyone's parade in this thread but it is what it is.
These are the tips I had on my car along with Track Nanny GPS when I blew a 95 with valved side deletes and an OEM center muffler. I feel like I'm raining on everyone's parade in this thread but it is what it is.
OEM side mufflers and center muffler plus these turndowns though, that's gotta pass 92 - I hope
So not exactly on topic but I blew sound today at Sonoma - meter read 98 in my 991.2 GT3 w/ valved side deletes, stock muffler/tips, PSE off and no track nanny (GPS). I would normally pass sound there when 100% stock. Spent the rest of the day short shifting out of 11 through 12 past start/finish in 5th. Last session of the day I got flagged again in 5th pushing it harder on the kink of 12.
Time to get some silened tips or get rid of the side deletes and go back to stock. I was hoping that the side deletes would be a bit louder but not too loud to fail sound at Sonoma
So not exactly on topic but I blew sound today at Sonoma - meter read 98 in my 991.2 GT3 w/ valved side deletes, stock muffler/tips, PSE off and no track nanny (GPS). I would normally pass sound there when 100% stock. Spent the rest of the day short shifting out of 11 through 12 past start/finish in 5th. Last session of the day I got flagged again in 5th pushing it harder on the kink of 12.
Time to get some silened tips or get rid of the side deletes and go back to stock. I was hoping that the side deletes would be a bit louder but not too loud to fail sound at Sonoma
Yeah track days through Simraceway at Sonoma are 96 dB . Rest of the time it’s 103 dB
they have a warning in their their website of which cars won’t meet the limits . Many track day organizers will inform ppl to get the track nanny from Alekshop
Yeah track days through Simraceway at Sonoma are 96 dB . Rest of the time it’s 103 dB
they have a warning in their their website of which cars won’t meet the limits . Many track day organizers will inform ppl to get the track nanny from Alekshop
Didn't know it was only Simraceway at 96. Interesting.
Will the track nanny help much with side deletes (valved) and OEM center. Is there enough muffler in the center when the valved are forced closed to get under 96?
Didn't know it was only Simraceway at 96. Interesting.
Will the track nanny help much with side deletes (valved) and OEM center. Is there enough muffler in the center when the valved are forced closed to get under 96?
From simraceway website (they incorrectly mention "sonoma". It should state simraceway days. I used to be a member of their Turn 1 club and it was the same 96 db restriction.
There is a lot of advantages of tracking at simraceway track plus days (very few cars on track with you). However, you still have to deal with the noise restriction. Best guy to contact is alekshop. Just about all the people who have the track nanny for Laguna Seca also have the coordinates for Sonoma programmed in.
ukducatti has tracked through the simraceway program and he meets the 96 db (He drives like his kids is sitting beside him though (inside joke).
From simraceway website:
2. What are Sonoma Raceway’s Sound Restrictions? The maximum sound output allowed in the Performance Driving Courses on Sonoma Raceway is 96 decibels. Most modern street cars do not reach this limit but some high performance, custom tuned and exotic street cars are challenged. The Porsche GT3RS, Porsche Cayman GT4 and Ford Mustang GT350 are just a few that run near or above 96 decibels. Please email pdc_info@simraceway.com if you believe your vehicle might violate the 96 decibel rule. Any cars running above 96 decibels will be removed from the raceway.
From simraceway website (they incorrectly mention "sonoma". It should state simraceway days. I used to be a member of their Turn 1 club and it was the same 96 db restriction.
There is a lot of advantages of tracking at simraceway track plus days (very few cars on track with you). However, you still have to deal with the noise restriction. Best guy to contact is alekshop. Just about all the people who have the track nanny for Laguna Seca also have the coordinates for Sonoma programmed in.
ukducatti has tracked through the simraceway program and he meets the 96 db (He drives like his kids is sitting beside him though (inside joke).
From simraceway website:
2. What are Sonoma Raceway’s Sound Restrictions? The maximum sound output allowed in the Performance Driving Courses on Sonoma Raceway is 96 decibels. Most modern street cars do not reach this limit but some high performance, custom tuned and exotic street cars are challenged. The Porsche GT3RS, Porsche Cayman GT4 and Ford Mustang GT350 are just a few that run near or above 96 decibels. Please email pdc_info@simraceway.com if you believe your vehicle might violate the 96 decibel rule. Any cars running above 96 decibels will be removed from the raceway.
Thanks for the info. I used to pass with stock exhaust but will the valved side deletes it's put me over. My homework over the summer is to
A) valved side delete + track nanny passes Sonoma. We know it won't pass Laguna .. and
B) valved side delete + silenced turndown passes Laguna with it without track nanny. It should pass Sonoma for sure as I only missed it by 2dB
C) go back to stock and get track nanny and pass Sonoma and Laguna
What I don't get is why is the sound limit 96dB when you're on the track with one group, but 103dB when you're on the same track with another group? The people living nearby who complain don't magically go oh you're racing with HOD instead of Sims? Aight floor it.
06-27-2019, 10:00 PM
