One out to two out?
 

I just replaced my cat with a FabSpeed pre-muffler and kept the stock one out muffler. I really like the extra growl in fact, I would like a little more. I saw some plans for making a one out stock muffler into a two out and was wondering what type of change in the sound that might make. Any ideas?

The Carrera 1 out to 2 out was/is a very popular modification. You'll get a much lower tone to the exhaust. There will be a bit of drone in the mid 3k range but overall many like the slight increase in resspone and aggresive sound. Here's a link on the process: http://forums.pelicanparts.com/showthread.php?s=&threadid=102817&highlight=muffle r

I just did mine. Very loud but yes there is some performance gain. According to some dyno runs listed by Steve Wong someone saw a little over 5% gain with the 2nd outlet versus stock versus a little under 5% for SSI's. Obviously at a much lower cost. I didn't use the Fabspeed premuffler just a bypass. I'll post pics soon. I'm planning on added a cap to the second outlet for around town and long drives. The sound is a little to much for the wife but not by as much as I expected.

I used a 30mm hole for the right side, which gave equal flow and sound out both sides. Oddly, the left exit gases were hotter. I didn't expect that.

Don't make the holes the same size....the right side can be "much" smaller.

Start small...you can always go bigger later....

Wil

I'd wait it out for awhile, maybe 1,000mi for a clearer idea of what you want if it's a maybe now.

I like Tom's suggestion of capping it or blocking it if I want to quiet it down for any reason. Thanks for the link Rick on how to do it. Does the length of the exhaust tip change the sound at all?

Here is a link with pics of my muffler mod on my '79 SC. I still want to buy one of Ben's eventually, but mine sounds pretty good and with my flanges I made, I can insert a cap or restricter plate if I ever want to quiet it back down.
http://forums.pelicanparts.com/showthread.php?s=&threadid=228406&highlight=diy+mu ffler

You could always buy a used muff and use that to play with. Many sell their old one when going to aftrermarket....and being made of stainless the condition is typically very good years after. Check the classifieds or Ebay.

I'll do a sound clip this weekend and post.