Tom, I really appreciate the real-world feedback as although my SD Qualcomm days are probably behind me, I definitely would love to drive my 914 at Laguna and other noise-restricted tracks. I have a stock intake plenum/filter setup in the garage and could definitely source a Phase9 or some other "quiet" muffler to meet a 92dBA limit, from what you describe. The 90 or below days seem like a lost-cause, however.

A lot of people at GGR with zoomy cars stick a sport muffler on top of the megaphones. Looks ugly but works great. Just make sure you suspend it well. Some folks suspend them with some strong springs.

This is a car from this years Time Trial at laguna, you can see more at http://community.webshots.com/album/148663513YNcYem:

http://community.webshots.com/s/imag...7cuxcva_ph.jpg

Hope this helps.

George

Having been at Laguna many times (mainly POC) with my 914-6, and having been black flagged (very frustrating), the only workable set up I found is stock airbox with filter installed, and stock 911/914-6 two in one out mufler. This set up works for 92 decibel days, but I doubt it would work for 90 decibel days.
The other thing you can do is to shrt shift up the hill just past turn 5. The sound both is just on tha right before the bridge, and manned by a couple of old ladies in tennis shoes.
Good luck.
Martin Jansen
#98 914-6GTR

I bought his old sport muffler that had 45s welded on the ends angled up left at 45 degrees.

I'm putting quieter mufflers on my car tomorrow for the Laguna event and I am going to turn the exhaust tips toward the driver side. Do you think it's better to turn them up 45o rather than horizontal? They'll be out past my bumper so I can do either.

Don't forget...they also utilize a roaming gal w/ a portable sound meter. I got black flagged there with Tracquest, along w/ a stock 993. To his credit, Todd was right there, telling them they were wrong. Went back out and came in under limit. The portable must be 50' away from the track...she often hides out at the top of the corkscrew.
You get three chances to make sound, too.

I'll be there this w/e w/ POC.

FWIW...I was at Brainerd in Minnesota. They have a gentleman's agreement on sound. I ran megaphones all weekend, noone ever blinked an eye. Got split by 3 cup cars on the dragstrip, now THAT WAS LOUD!!!
It REALLY hurt my ears.:mad:

WHen bending them away from the db meters, they should point horizontal or even upwards. I did some testing in conjunction with our friendly sound monitors last year... (Not the nasty snipers you guys have). The noise level was 1-2 db higher when my pipes pointed 45 degrees down and to the right than when they were pointed horizontal and/or upwards and right. (No consistent difference between the last two.)

Also remember that frequency of the sound also makes the db meter go up. A higher pitch registers louder. I was finally able to run straight out the back when I increased my output diameter from 1 3/4" to 2". This is why the rotaries have so much trouble.