RSchoeni

Thanks for the info Peter. My side pipes (glasspacks) are burned out. So, I'll be lifting early I guess . I've heard good things about Seat Time. This time I'll be at RR on Friday for a test and tune day with some local FL panhandle Porsche guys.
Regards,
Bob S

85Gold

I have run with Jon K. @ Seat Time a lot. He hosted a Cobra Club for a weekend and they all just lifted as they went by the Sound Meter.

It is funny as I think Spec Miata's are much more obnoxious the Cobra's.

Peter

Accel Junky

I'm reviving an old thread here...

Considering taking my side-bypass 997.2 GT3 to Roebling as well. Curious if over the years anyone can chime in with how that 50' 103db limit went down...Don't want to make the drive and screw myself. I do not have the side mufflers to put back on.

mark kibort

103 is pretty loud and yes, we deal with this every weekend. cold days or misty days are harder.. i have to use a turn down on those days. but, i have about 400hp, coming out of just a 3.5" pipe and a bola can muffler, so its not that hard.
most of the cup cars have no issues, unless they are running near straight pipes.
im sure the cup car guys can chime in.

mrbill_fl

fwiw, you usually get a warning or 2 if you're close. and 103 is pretty loud. 91-95db are normal limits. IIRC

You can often spot where sound control is capturing the db levels, (tripod with a directional mic, leading to a car or guy with a radio), and just lift or shift early.

I've used turn-down pipes that go over the exhaust and clamps, and turned them away from sound control. down, up or left or right. they were good for a few db's.

but I have seen cars DQed for it....

85Gold

My guess is if you still have stock cats and center muffler you should be fine. My 6GT3 with stock 7.2 headers, Cats and Center muffler passed sound OK at RR

Peter

mikew968

I have a 987.2 with fabspeed headers and fab speed race exhaust. I hit 105 at NCM coming out of T4 (tight RH turn). I put turn-downs on the tail pipe and directed the sound away from the meter and still popped 103 on a cold and wet day. So, If I have to live with 103 I would need to change the system. The mustangs and corvettes seemed much louder but they didn't exceed. The higher pitch Porsche engines seemed to be all having issues with 103. For most of us the answer was we didn't' go back to NCM.

Surfbum

I may be stating the obvious but shouldn't Sharkworks have a db reading?

A stock 997 and 991 cup will barely pass a 103 db @ 50' if that is any help. If it is cloudy we put on turndowns.

gobuffs

In the contract and enforced are 2 different things. 103 is in all the contracts at COTA. Never heard (pun intended) it enforced. Would be suicide for them for the cars they normally get there.