I have the Cappy Stage 3 w/ Hyperflows and it's the bee's knee's. I recently changed out the stock headers with wrapped Fabspeeds, and in open-air driving the F1 sound quality is slightly diminished (becomimg more throaty and growly, kinda muscle car-ish), though in tunnels and overpasses it still screams, maybe even a bit louder than with the Ansa headers. I strongly recommend new owners immediately replace Ansa headers with some variant of aftermarket, because even a tiny hole in those pipes can screw you major. To me it still remains undetermined, which comes first, the popped header or the burnt valve-guide? (Chicken or the egg, ha!)
Thats strange because my tubi does sound like an F1 car. Everyone tells me that my 355 sound better than any they have every heard. I have NO cats, just straight pipes and no bypass valve but the challenge pipe.
+1 95 GTB with tubi test pipes and tubi exhaust. I had an enzo owner tell me he wished his car sounded like mine.