I have a Flowmaster 40 series muffler right now, which I like except it's a little loud. Does the Flowmaster pose much of a resistance/backpressure loss by itself? I am contemplating leaving the Flowmaster where it is and installing another, silent muffler after the Flowmaster with a cutout in between the two. Basically, have the Flowmaster dump in front of the rear tire and the silent muffler somewhere near the bumper.

I don't like the direct popping noise of open headers, so I'm hoping that I can keep the Flowmaster tone and volume on demand and also have the ability to get out of sound-sensitive locations without setting off a dozen car alarms.

 

The flowmasters are not a straight through design like a Magnaflow or Borla muffler would be. People on here tend to really dislike flowmaster mufflers. You aren't running anything crazy, so I don't think there would be too much restriction, but its definitely not as good as what was mentioned above. You would probably pick up a few ponies by swapping over to a 3" magnaflow. I wouldnt bother with a cut out after the muffler, but thats just me. Maybe you can swap to something like a glass pack, put the cut out after that, and then a magnaflow muffler behind the cut out just to try and take the edge off of straight pipes with a cut out.

 

Cutout after the muffler is pointless in my opinion

 

Agree with Vortec350 and 2007 Chevy. cutout should be before any muffler or none at all. Just ditch the Flowmaster and get a straight thru large case design muffler-single 3"