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Posted by: john914somers Jul 18 2013, 07:02 PM

Sooo... I'm looking at all the different exhaust/muffler options for my 914/3.2 and I've heard that the noise ordinances at most of the tracks are becoming more stringent. What do you guys know about this and can anybody recommend a dual muffler set-up that is "free flowing" but yet will not DQ me at any of the local (Cali.) tracks??? Thanks for your input.

Posted by: r_towle Jul 19 2013, 08:44 PM

Whatever you use, mount turned down tailpipes, ones that you can change for each track base upon where the sound measuring device sits in relation to the car on the track....

Some meters are infield, some are outfield,
Turn your tailpipes away from the meter

Posted by: Trekkor Jul 19 2013, 09:02 PM

Thunderhill and Sonoma Raceway are both 103dBA.
Laguna is usually 92dBA.

My car runs dual glasspack megaphones and hits 99dBA at WOT under load. ( Carbs, so even loader )

I run a dual quiet pack for Laguna and it hits 88dBA.

Exceeding 103 is pretty tough, 92. Not so hard.


KT

Posted by: Randal Jul 19 2013, 11:06 PM

Individual Flowmasters and the big 911 air intake (mounted backwards with K&N filter and huge turbo bellmouth). Also put McMaster Carr egg crate sound deadening any place where the sound can bounce off the track and back up into the car. We had no trunk on The Beast, so it was an echo chamber. With all that you might make 92dBA at Laguna. Funny that most of the sound was coming from the TB and it was the most beautiful sound you ever heard.

Posted by: brant Jul 19 2013, 11:49 PM

I'm so glad my trip to Laguna in June at the Legends event was a "open sound" day...

what a headache you guys have adapted to.

Posted by: Randal Jul 20 2013, 09:04 AM

Do you know Pat Costin who runs a couple of different 911's? He was there running his IMSA car.

Posted by: brant Jul 20 2013, 01:10 PM

The name somehow sounds familiar. But I don't think I've met him