Db levels on stock side pipes

[Cone Basher]

FYI for you guys. I ran an Auto-x hosted by OVR SCCA and got my first report on my stock side pipes. They told me I came in at 93 db and the limit was 97 so I was OK. This is the first time I've ever went through a sound check and a couple of guys were not allowed to run again. I have been thinking about building a less restrictive system for my Coupe but now I'm starting to wonder about sound levels.
CB

[mmarshall]

Sounds about right CB. I was clocked at 94DB in Nashville. At the same time Bstuke hit 89 with just lobacks. His car is loud at idle but does not get much louder at redline. I am using a set of Magnaflows in my new system so we will see how loud they are.

[JKleiner]

I got a warning at 98 last year (roadster). I am confident that just turning the pipes down rather than out would bring me well under. Had some thoughts about making new quieter pipes last winter but it didn't get done...

Jeff

[Wade Chamberlain]

my old supercharged 306 with 10 year old FFR glasspacks was well over 100 and I got whacked at the DC ProSolo event a couple years ago. I rotated the tips down 45 degrees toward the ground temporarily (cut and S/S band clamps), and got down to 97-ish the next day on the same course.

My 10.5:1 347 with new FFR s/s pipes (stock exit) was 97db at a recent event.

[CraigS]

See my post here for a solution for a roadster;
Inexpensive exhaust quiet
You can do it in steps. Do the turndowns first and see how it goes. I installed the turndowns so they would go off and on easily. Slipped them into position and drilled a 3/16 hole thru both pipes.Dropped a small nail into the hole and then put a big hose clamp around and covered the head of the nail.The nail keeps it from being able to move and the clamp is just tight enough but doesn't distort the pipe.

[ltcjr71]

Don't look at Burn's stainless if you want to make it quiet. My quiet 306 with 14psi of boost was 107 db at the same event as Wade. After adding more packing and a cone inside, it was still 101 db this year. Has a great sound, but its not to nice for course workers.

[MikeKelly]

I did almost exactly the same thing that Craig did on a similar kit (Classic Roadsters, 4 into 4, sidepipes) and we went from 101 db to 95 db for autocross (measured @ 50'). It was a fall / winter project.

We're only using two of the auger blades (on each side) on that car.

FFR4FUN came up with a less invasive method, here's the link for that:

Flexible exhaust insert

HTH,

Mike