I have had 2 different set-ups on my Z . I started with the Greddy sp cat-back. IT was pretty loud, had a raspy sound to it . Some people like it, some don't. Now i have the B&B triflo cat back on there now and i love the tone of it! Real low tone that ins't really loud until you get on the throttle good. My Z is a NA so i think that the exhaust is louder on na's than on tt's even though i have extra resonators. Someone correct me if i'm wrong here.