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Old 10-18-2016, 09:48 AM   #1
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Lightweight exhaust that meets noise restrictions

I'm putting my 1998 on a diet this winter & plan to run test pipes & a lighter exhaust.
The problem is two of the venues I run have noise restrictions (90dB@75' and 94dB@50') and I've heard the typical 986 systems with test pipes are well over those limits.

Is anyone running a lightweight exhaust setup that can get under these noise restrictions?

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Old 10-18-2016, 12:28 PM   #2
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Here is my experience;

For 90dB, I run the test pipes and the stock muffler.

For 94dB, I run the test pipes and the Top Speed Pro 1 or equivalent eBay muffler (which is quite a bit lighter than the stock muffler).

When it comes to sound levels, your mileage may vary.
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Old 10-18-2016, 12:45 PM   #3
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Light weight low noise exhaust

I have an exhaust for sale that came with the Spec Boxster when I bought it, The exhaust is designed for Laguna Seca

Its basically a cat bypass setup.
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Old 10-18-2016, 08:45 PM   #4
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Quote:
Originally Posted by Black Sweeper View Post
I have an exhaust for sale that came with the Spec Boxster when I bought it, The exhaust is designed for Laguna Seca

Its basically a cat bypass setup.
Yep, that's the setup that should pass 90dB.
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Old 10-19-2016, 01:46 PM   #5
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In Germany we have another exhaust system. That has only the rear 400 cell catalysators and no catalysators at the manifolds.

My car documents say
Stand noise: 97 dB/A
Driving noise: 75 dB/A

Pretty shure that there are differences how the noise is measured in Germany and in the US. In general a US stock exhaust is louder than a EU stock exhaust.

Regards, Markus
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Old 10-19-2016, 02:45 PM   #6
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Quote:
Originally Posted by Smallblock454 View Post
In Germany we have another exhaust system. That has only the rear 400 cell catalysators and no catalysators at the manifolds.

My car documents say
Stand noise: 97 dB/A
Driving noise: 75 dB/A

Pretty shure that there are differences how the noise is measured in Germany and in the US. In general a US stock exhaust is louder than a EU stock exhaust.

Regards, Markus
I can't imagine it would be. For 986 in UK like most of Europe you just have the rear cats and the same single box design exhaust. I have recently swapped back to the standard 400 cell cats from 100 cell ones and whilst yes it is quieter I would expect another pair of cats in the system would dampen the sound a lot more.
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Old 10-19-2016, 03:29 PM   #7
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The US / export mufflers are different to the EU mufflers. They also have another part number.

Regards, Markus
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Old 10-20-2016, 06:30 AM   #8
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