Laguna sound limit
 

I’ll be doing another event at Laguna in another 2 months and have added a JDL 4 2 1 header and I have an axleback TRD exhaust. The header made it a good amount louder. Has anyone ever had a problem blowing sound with this or a similar setup?

If you're maintaining OE secondary cat within the FP/OP you should be ok.

For reference, not at Laguna Seca but I have JDL 4-2-1, JDL FP/OP Ultra Quiet Cat Combo, and Resonated Perrin 2.5" axle back and I'm around ~85-88 dB at 50'

Sound frequency can also change dB depending on what they're weighing it at. As long as it's not piercing loud high up in the frequency range IMO and experiences it tends to read lower, FWIW

I notice the opposite thing Monkey pointed out. We will have cars that violate local track dB limits (102db) that are pretty grunty - low/mid tones (NA V8s etc). But then you have a pack of Spec Pinata's come ripping through with crazy high pitched exhausts that pierces your ear drums and is physically painful to listen to, yet they register under 98dB. I just don't understand it.

Ugggg. Having to lift just after 5 and losing momentum going to 6 would suck. That's probably a good full second lost.

Fwiw I had a Tomei UEL and Perrin 2.5" resonated, with an OE over/mid, just went back to the OE catback for Laguna. I think the Perrin would have blew sound and as you said, lifting sucks ass but what sucks more is losing a day because you're booted for sound.

Also, fuck Laguna. It's boring in slow cars.

This has been my experience with motorcycles as well. A lot of area's in OR are heavily sound regulated. A two-stroke that sounded loud would pass, a thumper that sounded comparatively quieter would fail.

So the take away is go for your PB on your last lap of the day

I changed from the nameless axleback to OEM in <15 minutes without jacking the car up, two nuts some Windex and wiggling gets the job done. That sounds way less frustrating to me than remembering to lift every lap past the sound booth.

Out of curiosity, what kind of modification do you have on your car, and what kind of lap times do you put down?

I love Laguna. Great track no matter what you drive IMO

He no longer owns the car, but it was an STX Prep build compliant to SCCA Ruleset.

TonyR is a very good driver, this was at NCM last year FWIW:

https://www.youtube.com/watch?v=Q_CZPjkddq4&t=

Gotta love forums. IIRC 1:45 with really basic bolt ons and dead RE71's? Canned tune, tomei UEL, megan/proparts coils.

It's fine, I know a lot of people dig that track. It's iconic. I have a lot of hours there and it just does not do it for me. BRP, Sears, Thunderhill, and even SoW are a lot more fun and worth my entry/consumables. Also every car that I've taken there had a sound issue of some sort, it really sours the experience.

For me, the run down the straight/to 5/up the hill is just too long with low power.

Edit: I just recently did Big Willow with no power, and by no power I mean 120whp on a cold day. Laguna is a lot like that for me, if that makes sense. Lots of throttle, lots of waiting, hard on the engine. Ultimately did two sessions and decided to pack it in. Big Willow is bad ass and fun with more power, and I appreciate the track, but if you put a 90dB sound limit on Big Willow then the cars which actually make power can't play there. That's Laguna. Does that make sense?

It was crazy long before they built the infield in the late '80s.

That's pretty solid.

SoWS is imo, boring. Every car takes roughly the same line, and it's just an exercise in frustration. Effectively, it's an autocross with two straights.

WSIR, while "simple", yields HUGE returns in speed for small improvements. Friggin awesome.

Yes, the dB restrictions at Laguna are straight up stupid.