never heard of a baffle inside a sled pipe?
does your riding area have noise laws?
stinger size is enginered based on the bore/stroke/rpm of the engine, head pipe lenght and diameter, cone length and diameters. they dont build a pipe and then think, "heck we got a bunch of 1.25" pipe left over from last year lets use that.
granted in mass production they might take some hp off the shelf from several different models to use as much similar product.
you can make more power by changing the stinger pipe, you can also burn the engine down by chainging the stinger pipe,
if you have no can on there at all it will sound cool for about 1 minute, after that your ears will hurt and you will be no fun to ride with.