Luguna Seca noise limit
 

Due to a modification I can not just swap stock exhaust. So what's the best way to measure noise levels...

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Noise levels are notoriously difficult to measure consistently, they depend on so many factors that you just want to find out how the track measures and reproduce as closely as possible while throwing in a bit of a safety factor.

Can you do further modification? Perhaps throw in a bend pipe and make an authentic laguna pipe.

Laguna pipe or lift

We have used both CC inserts, and Super Trapp end caps.

To measure decibels, download a mobile decibel-reading app, like Sound Level Meter or Decibel Meter. You can also measure decibels using computer programs like Audacity or Decibel reader. Another option is to use a profession decibel meter, which can give you a very accurate decibel reading.

Lift coming out of T5

Sure, you can lift going past the shack, but they also go around the track with a mobile unit.

Has anyone ever actually had a issue with the roaming one?

Not sure. I know the sensors in the shack are pointed at T6. Really screws you up lifting at the shack.

Back in the day we used a Super Trapp.

Why is your exhaust that loud anyway?

I was behind a heavily modded 1 series today, in traffic on a single land road. Straight cut gears and perhaps the loudest exhaust I've heard on the street. For two miles, all I could think was, "douche bag". When he didn't turn off onto our road, my wife and I sighed in relief. She was probably extra happy because I would have ridden his ass the whole way through the canyon, just to show what a moron he was.

Loudest car I ever heard was an RX7 at Big Willow. My god, that was a rock concert. But then that was a pure track car.

Yeah IDK why any racing body go beyond the bare minimum to satisfy the rich bois on the hill

I've done probably 1000 laps there and have never seen it. Have heard of it though. Now that their under new management who knows what they'll be doing, 90DB sound limit is already absurd.

You don't have to have a loud car to fail sound on a 90DB day at Laguna. Stock cars fail all the time. I have a big suitcase muffler, highflow cats and Laguna pipes and I still barely pass (with a V8) on a 90DB day. 1 out of 10 laps I'll still get flagged for sound so I go about 1 foot off line not to chance it.

At the same time I'm with you and don't understand the loud cars in town. If you want a super loud car just get a cutout but only use it in the canyons or at the the track (without sound limits). No need to attract so much attention to yourself and annoy people. If you want that much attention just wrap your car neon instead...

CSG Touring 86 or ACE Laguna Cat-Backs will let you pass Laguna sound limit on a car with aftermarket header and midpipes:

https://www.counterspacegarage.com/b...a-sound-limit/

Will the stock catback also pass? New setup will be as follows

JDL 4-2-1 EL header
1320 OP
JDL ultra quiet FP with dual resonators
Stock mid pipe
Axle back for when I want to be loud
Stock when I want to be quiet or pass 90db days

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Yes, I've passed sound check at Laguna with full exhaust and stock catback/muffler. The CSG exhaust does sound better inside & outside the car, is less restrictive and is marginally lighter than stock, while still keeping absolute sound levels low.

What about the q300?

It'll likely pass, but the exhaust itself is slightly heavier than stock (if we're talking about just the catback).

I like the idea of the CSG exhaust, I just get the feeling that outside the exhaust tips the only noticeable difference from the stock catback is the $850 hole in my wallet.

Hence keep the stock catback. When you want to be loud, get an axleback muffler delete. Way cheaper and super simple to swap.

How do you like the MXP-SP with the 4-2-1? I just ordered a JDL 4-2-1 yesterday

It's pretty damn good. I still have my stock FP and I replaced the resonator with a bigger one from vibrant

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I have it with the JDL 421. Sounds throaty and not too loud. I had a TRD with the JDL and it was just too loud for my liking It may have passed at Laguna but not sure. I did a sound check and it appeared that it would though. I had it at Willow springs and it sounded more racecar but driving to and from the track it was just too much. I actually enjoy driving the car now

Stock front pipe?

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FWIW:

JDL 4-2-1, JDL Ultra Quiet Catted FP/OP , Perrin 2.5 Resonated Exhaust.

https://www.youtube.com/watch?v=73Io...nel=KyleHerbst

It's super quiet.

Do you have a resonator with the cat?

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Yes, it's the resonator + cat combo.

So, within the exhaust stream I have a resonator in the front pipe and a resonator in the Perrin exhaust.

Would the stock FP/OP be quieter than the JDL ultra quiet?

I imagine it would be. There is a muffler on the stock FP.

To add to this thread, I have the Legsport dual cannister axleback and it is super quiet. I just ran it at Lime Rock Park on a muffled (86db) day and had no issues with sound.

Aftermarket header, jdl ultra quiet frontpipe, Legsport midpipe, LegSport Club Sport Street Axle Back Exhaust.

https://i.ibb.co/dtb9NZt/pwdrivlzdkgcfiurbfkr.jpg

Aerodynamically, the OEM catback muffler and those with a similar shape like the CSG Touring 86 are best.

The CSG is awesome you can’t go wrong with it

Remember one tracks measurement may not translate to another track.

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