[bobcowan]

This is becoming more and more of an issue. The tracks I use are in the middle of nowhere, without a house to be seen for miles. So we don't really have sound limit here.

But other areas it's a real problem. 600hp running through a single side pipe can be darned noisy. dB radings taken in the cockpit are not that reliable, because it's influenced by noise from wind, tires, transmission, diff, etc. The sound reading need to be taken from the side of the road/track.

The spiral/auger core mufflers Wayne mentioned are from LoBack. They are custom made to whatever length you want. You can get 30" mufflers to fit. Uless you have a Classic Roadsters, then you could probably fit a 34-36" muffler.

The other company to look at is Classic Chambered Exhaust, built by Iron Man. It's essentially a glass pack. I recently installed his 28"x3" muffler. The mufflers I replaced were shorter smaller glass packs from FFR. I also angled the opening 45* towards the ground. I did a write up on the installation.

I'm quite pleased with the results. It is definatly quieter than it used to be. And the sound is softer, more mellow. I hear mechanical sounds now I didn't hear before. It doesn't assault the ears like it used to. I'm going to the track in a few weeks, and we'll see how they sound at speed.

That may help. I saw a picture of a simple exhaust mod that someone did to get them below spec. It was a simple alum sheet mounted about 6" in front of the opening. The exhaust soiund hit the sheet of alum, and broke up (I guess). Anyway, it worked for him. That would be easy to do, and easily removable.