I am designing a muffler for my Porsche and came up with this design. Just picture the center area packed with fiberglass. It's basically a cherry bomb folded up.
I would like to absorb most of the high frequency sound with the fiberglass, while allowing the lower frequency sounds to pass through. This is my first muffler design, so no laughing please.

The inlet is 2", the perforated center pipes are 3" OD and the U-bend is 2.5" mandrel bent tubing with a 2.5" radius. The oval casing is 5" x 9" and the overall length is 10.25". Weight will be 7-8 lbs.
I don't expect to gain any power with this, but I would like to get a nice deep sound from my car without it being too loud inside.
Is the fiberglass going to hurt/help the airflow. I think it will help direct the exhaust flow through the perforated chambers, but I am not sure...

Any thoughts or comments on this would be appreciated.
Thank you,
Peter

 

Kind of looks like this...Fabspeed design.

 

Dang,
Yeah that looks almost identical. There are only a few ways to package components into that small of a space!
I will search the forums for personal opinions on the Fabspeed mufflers since mine should sound similiar.
Thanks!

 

The lack of packing will add sound but can decrease airflow efficiencies through the muffler.

Racecar straight through mufflers make more power freshly packed with packing (stainless steel type packing) than those mufflers that have 'burned out' so to speak, needing repacking.

 

Hit up Fister D.... He has the BEST mufflers out there

 

I don't know if this would fit in the location of the stock muffler but just passing the info out there

http://www.summitracing.com/parts/PYE-MVR50S/

http://www.summitracing.com/parts/MPE-14210/

 

Before you go to all the work on your design you really should hear what one of the easiest muffler mods on earth sounds like...namely the LPMM 2" bypass. I have it on my car and get constant compliments...no droning on the highway and can certainly be heard from a long ways away when you are on the gas. PM me if you want to hear it in person. Cost is only $25 in materials and another $80 in welding or free if you weld yourself.

 

If your design is using fiberglass packing or stainless steel wool, eventually you will need to open it up and replace/repack once they burn off. Not a big issue for a race car but a PIA to have mufflers that require periodic maintenance.

 

Use Rock Wool, not fiberglass, & make the cans louder, so you can pack more in them. But why are you going through all this? Why not just purchase what is already out there?

I would like to see what they look like when you are done.