I have a 3-1/2" dia. 2 Chamber Flowbastards under my red Charger with an X Pipe reduced down th 3" out the back thru the stock R/T tips with the tapered (2-1/4) portion of the stock tips eliminated with no resonators & it is loud. All home built in my garage. I get more compliments all of the time while driving or at the cruise nights that it is the sweetest sounding "full" exhaust car everyone has heard. I must be getting old. To me it is too loud for as much as i drive it. I may trying adding the glass pack resonators in the tail pipes on either side of the gas tank this year.