I had to make some baffles for my pipes. They are not SS pipes, but the principal is the same.
I tried the "wrapped" baffles and I think they got louder so I made my own.
I used a 10 inch tailpiece from a sink drain available at most home improvement stores for under 5 bucks. I used a large washer and attached it to the flat end (other end is flared) cutting several "fingers" about an inch into the end of the pipe and fitting the washer in the end and bending the fingers over the washer. Then I pop riveted the fingers to the washer. I experimented some with the inside diameter of the hole in the washer and found for me the smaller the better.
I then drilled holes at the 0,90,180 270 positions around the pipe. they are evenly spaced, the same size and same number of holes in each row.
The number of holes will also determine how much back pressure you build as well as the size of the holes.
I then inserted the baffle into the INLET of the muffler pipe and secured with a small set screw.
The ID of the inlet is 1 7/8 while my baffle was 1 1/2 with a flare of 1 7/8. Just worked out like that.
I love the sound now and have restored the loss of power due to loss of backpressure. It is probably 30% quieter now and I was only out $15.00 for both baffles.
Just a thought.
