At the last PCA track day at Laguna Seca, I got black flagged several times for sound violations, up to 96 db. All this with a stock exhaust! I thought I'd be fine even with their 90db limit due to the sound attenuation of the turbos. The only power mods on the car are a EVOMS chip, 5 bar FPR, and diverter valves.

I don't know how to go quieter than stock, and lifting past the sound station is a bummer. Any ideas?

 

I think up shift and up lift is ur best bet

Getting exhaust extension pipes pointing to left is the other option

 

Wow, that's horrible! I don't even go to tracks with strict sound limits. My advice is go to another track. Changing exhausts and stuff is for the birds.

There are baffles you can buy though. I think about $100 each that will reduce sound further. They sell them at atlanta Motorsports park.

 

Another track? No way, Seca is the best!

As dj stated above, key is to make extensions pointing away from the db meter. Up shift and if they still complain lift. It does the trick as I have a full 3 inch "X" exhaust with no cats.

 

This is not pretty, but it works. Have had similar issues at Laguna myself. You can get everything you need at Summit racing.

 

i never figured a stock 996 for a 'loud' car ! sounds like their limits are totally unrealistic, i wonder what other stock cars are failing

 

Maybe I'm spoiled by having a lot of great tracks within a few hrs.

Road Atlanta 20 min
VIR 5 hrs
Barber 2.5 hrs

I wouldn't bother with a track that was that much trouble to run.

I hear Sonoma is better anyways. Hoping to see for myself this fall.

 

Yeah lift or do the side-out tips. Something still sounds off though. We run stock there to avoid the "little shed" with the mic. Is it possible the cats are gutted?

 

The only easy solution is to lift. Otherwise, the posts above about using extensions to point the tips away from the meter is really your only option short of cutting your mufflers open and adding more baffles (not really an option).

+1 to that! How can any stock car/exhaust fail at a track?

 

love the left tips hahaah, that's . Seriously they don't flag you for that? It's clearly designed to trick the sound meter.

 

The car passes smog no problem, so I doubt cats are gutted. I noticed that the sound–more of a rasp like a jet than a typical exhaust sound–is not linear to RPM or load. It seems like the car sounds "normal" and then all of a sudden the sound kicks in about 2/3 of the way up the hill, i.e., right by the sound booth or maybe 6K+ RPM in 3rd. I thought perhaps it was from the wastegates dumping out extra boost pressure, but the wastegates still dump into the exhaust upstream of the mufflers, right?

There were a couple of other 996 turbos there that day, at least one with an aftermarket exhaust, that were not getting black flagged. The only material difference with mine is the K24 turbos. I'm willing to make the "laguna pipes" but first want to rule out some issue with my exhaust system making it louder than it should be.

 

Yeah and sounds like you are just the right pitch for the thing to pick up.

 

Is your car an X50 or regular turbo? I'm assuming since you say K24 it's an X50, which does have a louder exhaust than a regular Turbo.

I would agree, the X50 car definitely has a distinctive (and louder) sound versus a regular Turbo.

 

Yeah, the track marshal, who I had too many occasions to speak with, said the car sounds like a jet plane down the front straight.

 

I got black flagged in my first session at LS also even with track tips. The rest of the day I took it easy on the gas pedal after turn 5 and had no problems. On 90db days that is really all you can do.