G'day.
I'v got a S2 vy with stock motor, Pacemaker extractors, magnaflow cats, and a 2 1/2" mantra cat back with muffler and resi. vewry loud when u give the boot, nce rumble at idle. and no drone at all.
all said and done, if i'd know what it would sound like, i would'v gone lukey cat back...