Rob S

Reviving an old thread here because I'm considering making my first trek to Thunderhill in late June for a private, two-day event, and I'm concerned about their 103 db limit. I have a 996-3 with a very loud exhaust built by Charles. I have no idea what sort of sound levels it produces, but I bet it's more than 103 db. RL'er 007DT, who had a similar exhaust, saw an unofficial 109 db at a different track.

Questions: how often is the sound limit enforced? Are the sound police there at every event (even one on weekdays when the total number of cars is only 30)? Where is the sound meter? If I take turn-downs with me, which direction am I most likely to have to face them?

Thanks for your thoughts.

Rob

ex10psi

i'll be at this track day as well, look forward to meeting you Rob... pj speaks highly of you.

i'm also concerned about the sound metering... i am running muffler bypass.

P.J.S.

Take a book Elson and rob so you have something to do while you are not driving :-)

(Teasing you guys)

gigharbor1

This private event in late June is going to be full of guys from the PNW. That is a long haul to be told you are not allowed to participate because of sound readings. I am invited but I can't take the risk. I have a Rothsport 3.9 in my 964 and with very little muffling. I have been advised to put on Supertrapps, but all this talk about engine/muffler damage from heat makes that seem risky as well. Oh well, it would be fun, but a big risk.

speedoflight

TH don't have a fixed sound booth like LS. but when they measure sound, the humanoid carrying the sound meter is usually at between T14-T15. so point your downpipes to the left. there are RARE days/hours that they are enforcing it. i've been meatballed once with the sharkwerks bypass. side muffler bypass will be fine. it's not as loud as center bypass.

Rob S

Elson,

Actually we have met - at the last PCA day at the Ridge. I didn't have my car, though so you might not remember. If I go to THill, I'll look forward to seeing you there. Oh, and I must have PJ completely fooled if he speaks highly of me. That or he's thinking of someone else.

Also, thanks to the others for your thoughts. I'm not sure whether turn downs will help enough, but it may be worth carrying some and aiming them strategically if need be. I thought of trying to do some sound level tests here at home beforehand, but I think that such readings are so funky and variable, there's almost no way they'd be reliable. I kind of have to just go there and hope for the best.

I also have another backup plan -- I could switch back to the stock exhaust at home. Or I could even switch it at the track if I get meatballed. But lying on my back for two hours is not how I enjoy spending a track day. And after developing the car, it's a shame to throttle it like that.

Rob

stujelly

I have the sharkwerks center bypass on my RS and it was a cloudy day and I popped a 106 db. The sound meter was at the start finish.

I suspect it had to do with the over cast as there are other days i have never been harassed.

ex10psi

ah right, hi rob i do remember you! it was nice meeting you at the ridge, really hope to see you at the thunderhill event. i am confirmed and will likely just use my factory mufflers, def a shame, was looking forward to running the muffler bypass pipes.

i actually called cantrell and got confirmation on the 103 db restriction, boo.

rja

Thanks for this thread. There's a private 2-day event I've been planning to attend at Thunderhill at the end of this month (June 24/25) w/ Cantrell. I just now learned there's a 103db sound limit. Silly me for not checking to see in there's a sound limit on a track in the middle of nowhere!

I run full Akra race exhaust (header + hiflo cats + center, but no side mufflers) and I'm pretty sure it will bust 103db based on video link below (but I haven't measured myself), and of course depends on distance measured from, air density, etc. From reading this thread, it seems like a crap shoot at best. This is a big trip for me and therefore having car transported down -- hence a big time and monetary expense, and not worth it just for 1 lap of Thunderhill.

It's a longshot, but anybody w/ full Akra having Thunderhill experience to report? I think Pete had the same setup so -- if true -- it does not bode well for me.

stujelly

I ran a 106 on a cloudy day with just a sharkwerks center bypass. On a clear day I dont think you will have a problem. I know they make sound meter apps for the iphone, as corny as this may sound maybe you need to make a few test runs past someone with that app and see what Db you pop. The great thing about private track days are you do get a little more love from the track officials than if it were a NASA or PCA sanctioned event. Sounds like fun.

Worst case is you have to let off at the start finish everytime, which would not even be worth going at that point. Good luck hope it works out.

usctrojanGT3

That's complete BS. I wanted to go up to LS for the BMW CCA event in August but there's no way I'll go now since I got my fabspeed exhaust put on. It's a damn track, I don't get why there are db limits. I say everyone boycott TH and LS...let's see how long before the sound police changes their mind.

drl

I do not agree with but understand where the laguna sound limit comes from....but TH? Never been there but isn't it in the middle of nowhere? Who is imposing the limit there and how do they get away with it?

skxf430

Must be disturbing the grazing cattle at TH.

mooty

surely you dont want to drink milk from cows that are scared by loud porsche exhaust do you?

DC640

LOL