I installed the qs ss in my murci and the thing is loud as sh-- !!! The sound is like a cross between a race bike and an indy car in high rpm's with a deep growl in low rpm's . But a big difference in performance as well . The 4 pipe exhaust tips i put on look great and get compliments on them daily . If you want the car to be able to sound really loud/mean install them , and you can just drive the car in a higher gear if you want to keep the noise down . Thats what i do . I have 2 of the 4 cats of the car out , so if you want to keep it more quiet , leave the cats in and dont install the cat by pass pipe . I had tubi in my diablo sv and wasnt that crazy about it as the sound wasnt what i was looking for . Well good luck with the exhaust quest and keep us posted on your decision ..