i can’t help you with the piping q cause i got a muff and 2.25 all at once but after i put my header on i notice it got raspier earlier in the r’s and a little louder
let’s say w/ a resonator at the middle pipe? Right now my set up is 2 1/4" axle back w/ apex’i N1 style muffler, If I change the middle pipe w/ a bigger diameter would it calm down the growl of the muffler of would it just make it more louder?