alz

Hi,
I'm really looking forward to going to Laguna Seca next weekend, but amidst the excitement I forgot to think about sound levels.

I have a stock 2013 C2S with PSE, and it's a 90db limit event. Has anyone else run there with a similar car and passed the sound limit? Are there any special tricks needed to pass this? I'll definitely keep PSE off, although I believe the PSE valves open automatically after 4000rpm anyway so that won't help.

I've done some forum searching, but most threads are either for GT3 owners or for cars with aftermarket exhausts... really hoping my stock car won't have any issues.

Thanks

Archimedes

Sorry to say it, but you're not going to pass sound there with PSE, even with it turned off, as the valves open above 3k RPM even with it off. Only option is to lift going up the hill and see if you can beat the meter.

Grunty

If a 911 stock can't pass the sound rules, how do they actually race anything there? Are the sound restrictions lifted for races?

Comanche_699

I'm with Grunty.

Hammer up that hill, and see what happens. You won't get shut down for ringing the bell, but you don't get a lot of tries.

if for some reason your banging over 90db in a stock Porsche, THEN you can lift your foot out of it on the next lap. But I really don't think you're going to be too loud.

You can get cheater pipes / diaper pipes / bendy pipes - but I'd be real surprised to learn that 90db actually impacts the likes of bone stock modern Porsches.

I'd love to find a place in the north bay with a decibel meter and find out once and for all how many db's mine lets out OT.

And yes, they let the cars roar on Raceday.

My understanding is this 90db ruling is really held in place by a tight knit group of like 11 people from the community. Mind blowing if true.

simplex

I have no problem passing 90dB at LS in my 991.1 C2 with the stock exhaust (no PSE).

Archimedes

There are a certain number of unrestricted days at Laguna, most of which are taken by race organizers. Track rental is much more expensive on those days. Every once in a blue moon one of them comes open and gets snapped up by a track day organizer.

Archimedes

Absolutely not true. Not only is it not a small group, the sound issue itself goes all the way back to when the track was put there.

Archimedes

Big difference between PSE and non-PSE. PSE will not pass.

OP, you should find out how many strikes your track day organizer allows before you just open throttle it up the hill the first time. Some only give one chance to correct. If that's the case, you don't want to waste that first one and then be worried the rest of the day. Might be smarter to short shift up the hill from the get go.

Leecw

I don't think you're going to have any issues - I had my 2014 C2S w/PSE at Laguna on numerous 90db days without issue, and if for some reason to get flagged for sound, it's not like its 1 and done, go back out and don't accelerate as hard until you're past the sound shack, you're not going to go much slower up the hill and it will not change how much fun you have with your car at the track.

R_Rated

Pay no attention to the aftermarket portion but this is in an enclosed area up close to the exhaust:


Make sure and watch to the end when the car is not in a metal building.

cajerseyboy

I run my 2015 991 GTS with PSE on full throttle around turn 5 on 90db limit days w no sound penalty. You should be ok.

mallocfailure

I'm convinced it's a roll of the dice - I hear about stock Cayman GTSes getting meatballed every once in a while, but when I ran it in my own Cayman GTS I had no issues with sound. (I know you're asking about a 991.)

If you search you'll see some elaborate solutions, including a GPS-controlled solenoid that closes the PSE as you approach the sound booth. You'll also see a lot of exhaust tips that point the exhaust away from the sound booth.

I agree with the recommendations - run the track and forget about the sound booth unless you get flagged, in which case just letup a bit as you pass that section of track.

kayjh

I don't think your correct on the valves opening over 3000 RPM with PSE defeated. I've read that on this forum and spoke directly with my SA about this as well as the sales manager of the dealership. They were both emphatic that the PSE valves do not open at any RPM with the system defeated. I asked them to contact PCNA and get confirmation of that "fact" and the next day they wrote me to confirm it.

There may be some valves in the non PSE cars that open up as the RPM rises to allow freer breathing, but according to my SA, the PSE is fully deafeatable.

kayjh

Its hard to know how far the db meter is away from the car's tailpipe, but the standard measuring test is the db reading at 75', not right beside the tailpipe (as far as I know).

bossboy302

Actually, while Monterey County measures and enforces the sound levels, and it does go back a long time, it is pressure from local residents, mostly in Tehama, that continue to oppose higher sound limits resulting in fewer and fewer open sound days, or even 103db days. Come to Sonoma instead.