Well you did not list much info on your current set up but they can help with some set ups but really the restricion they offer is in the wrong area, they bottle neck the port for a short legnth , building more heat in the chamber. Look at most systems you will find that the restriction is not at the mouth of the pipe but else where and a longer legnth of restriction.
I have seen them help with true drag pipes on shovels but then again I doubt your are riding a shov.
I have seen them help with true drag pipes on shovels but then again I doubt your are riding a shov.