90db Exhaust List

[ats*ben]

I've been trying to find more information on what exhaust setups are able to pass the 90db sound limits at Laguna Seca. I figured a single thread would help in people listing their exhaust setups and/or if any lifting is required to pass. I would also love to see if anyone just has test pipes and is able to pass.

Post up your exhaust setup and if you need to lift or have "Laguna" pipes to pass!

X-Pipe:
Rear Section:

Pass at 90db:

Stock X-Pipe + Supersprint Race F1 Rear Section = Bimmer Barney

Stock X-pipe + Akra Evo Titanium Rear Section = Bimmer Barney

Stock X-pipe + M Performance exhaust - kyippee

OEM Xpipe + SuperSprint F1 Race Rear Section - Derbo

Stock x-pipe w/ Primary Cat Delete + Dinan Rear Section - nickauger **92db**

AFE Resonated X-pipe w/ 300 cel cats + OEM Rear Section = roastbeef

Challenge Sport (cats+resonators) + Stock Rear Section - fsmtnbiker

RPI Catless X-pipe + Stock Rear Section - P1zzaboy **Pass at 92db**

Supercharger w/ Akrapovic Evolution X-Pipe + Stock Rear Section - dogbone **Pass at 93db full throttle, 90db with lift**

Akrapovic Evolution X-pipe + Akrapovic Evolution Rear Section - fsmtnbiker

Fail:

Stock x-pipe + Bimmerworld street exhaust (~94 dB in 2018) - kyippee

Evolve HFC resonated x-pipe + Bomiz valvetronic muffler in quiet mode ~93.4 dB vs 104 db in loud mode - kyippee

[kyippee]

The following are at full throttle, ideal gear (at top of 3rd gear for me) going up-hill, staying to the far right of track while passing the sound station. Beware that in 2020, they seem to have moved the microphone closer to the track. What used to pass in 2019 may not pass anymore.

Pass
Stock x-pipe + M Performance exhaust = pass (in 2018, I bet it still passes)

Fail
Stock x-pipe + Bimmerworld street exhaust = fail (~94 dB in 2018)

Evolve HFC resonated x-pipe + Bomiz valvetronic muffler in quiet mode = fail (~93.4 dB in 2020)

Evolve HFC resonated x-pipe + Bomiz valvetronic muffler in loud mode = fail (~104 DB in 2020)

[dogbone]

Supercharged.

X-Pipe: Akrapovic Evolution
Rear Section: Stock.

93db at full throttle. Can pass sound if I lift just a bit.

[kyrix1st]

90dB is ridiculous. Don’t some cars have louder exhaust from the factory?
Should sue them if the engine blows due to primary cats collapsing...

[nickauger]

pass 92 db with test pipe, oem xpipe with secondary cat, dinan rear section

[fsmtnbiker]

Pass:

X-pipe: Challenge Sport (cats+resonators)
Muffler: Stock

X-pipe: Akrapovic Evolution
Muffler: Akrapovic Evolution

On both setups, I also have had the MS Intake. Never had issues on a 90db day, no short shifting, no swerve between 5-6.

[roastbeef]

pass: afe 300 cel cats, resonated xpipe, oem rear section.

[Bimmer Barney]

Pass:
Supersprint Race F1 rear section, otherwise stock.
Akra Evo Titanium rear section, otherwise stock.

No goofy Laguna pipes and I don't lift.

[ats*ben]

Updated. Thanks for all the feedback everyone. Keep it coming!

[P1zzaboy]

Passed 92dB:

RPI catless xpipe
Stock backbox

[racer_951]

fsmtnbiker, did you pass 90db or 92 db with Akrapovic Evo exhaust. I have an e92 with full Akrapovic Evo Titanium (I guess it is the same as yours). I was thinking about getting an OEM rear section to quiet it down. But if you pass 90db, then I don't have to worry about it.

Btw, great lap times at LS and other NorCal tracks!

[dparm]

Originally Posted by kyrix1st

90dB is ridiculous. Don’t some cars have louder exhaust from the factory?
Should sue them if the engine blows due to primary cats collapsing...

A C7 Corvette will not pass with stock exhaust, as I understand it. I suspect many of the modern Ferraris and Lambos won't either, they're loud as hell.

[P1zzaboy]

Originally Posted by P1zzaboy

Passed 92dB:

RPI catless xpipe
Stock backbox

I think wether the setup passes or not is dependent on driving and climate. I was banned from last event with the exact same setup than last year. I’ve been running 3 sec faster on a 2 min course, so probably higher in revs. Also I did the first half of the day without issues and got black flagged in the afternoon right before it started to rain.

I am currently working on a solution to quiet even more the stock backbox, I do not want to replace the xpipe and detune for each event.

[kyippee]

Originally Posted by P1zzaboy

I think wether the setup passes or not is dependent on driving and climate. I was banned from last event with the exact same setup than last year. I’ve been running 3 sec faster on a 2 min course, so probably higher in revs. Also I did the first half of the day without issues and got black flagged in the afternoon right before it started to rain.

I am currently working on a solution to quiet even more the stock backbox, I do not want to replace the xpipe and detune for each event.

I'd also like to note that Laguna Seca seems to have moved the sound measurement microphone closer to the track. I think a lot of us who used to pass in 2019 won't pass anymore.

[fsmtnbiker]

Originally Posted by racer_951

fsmtnbiker, did you pass 90db or 92 db with Akrapovic Evo exhaust. I have an e92 with full Akrapovic Evo Titanium (I guess it is the same as yours). I was thinking about getting an OEM rear section to quiet it down. But if you pass 90db, then I don't have to worry about it.

Btw, great lap times at LS and other NorCal tracks!

I passed 90db with SpeedSF on July 5 this year. No warnings, no lifting or short-shifting either. I was surprised but super happy. I ran a couple 90db days there last fall as well with no issues.

My car also has the MS intake which might add a db or two, but overall the car is surprisingly quiet from the outside. Make sure the donuts at the header->x-pipe connection are in good shape too, those being even a little bit bad will add noise real fast.

[911r]

90db is crazy. Assume I'd instantly fail with super sprint race mufflers, macht schnell test pipes & macht schnell intake?

[derbo]

I passed 92dB

OEM Xpipe + SuperSprint F1 Race rear exhaust.

911r I'll come back one day with test pipes and try again.


Btw, love ATS Garage. Reminds me of the good ole honda days.

[Tommysalami]

How far is their microphone from the track? I've had my car measured under 90 db but from a point 50 ft away

[fsmtnbiker]

Originally Posted by Tommysalami

How far is their microphone from the track? I've had my car measured under 90 db but from a point 50 ft away

Measuring on google maps it is ~60’ from the edge of the track. In my DCT car I am going past the sound booth at about 8000rpm in 3rd, so pretty much worst case. A short shift to 4th there probably quiets the level down a few dB.

[Davisca455]

Full Akrapovic
G-Power SKIICS Supercharger

Meatball flag for me at Laguna this morning.
Blew a 92.7dB
I was in 4th gear going up the hill towards Turn 6 on the right side of the track (closest to the sound booth).

The organizer told me 92dB won't get you in trouble, but over that, they are gonna say something.
Apparently the organizers are allowed 24 sound violations per day, and the 25th violation results in a track shut down.

*Edit*
Session 2, no violations.
I short shifted it to 5th and am not near full throttle, less than 5000rpm.
Still fun.