Cat backs, but not axle backs. Cat backs have 3" pipes throughout, and axle backs 2.5", for stock exhaust pipes. I kind of put 2+2 together by seeing Borla full cat backs use resonators. Plus S650s are louder than S550s. I have a Switchfire on my wife's S550 Mach 1, and it sounds so good and deep. Same Switchfire on an S650 gives a slightly tinny sound, but improves power. So I put a halt on the project. Going to exchange the Borla S Types for Steeda Race triax short stroke shifters, and put the Switchfire in her dad's Mach 1. 120 db is too much for me. So I'll be studying up on sport touring mufflers. A real loud combo of Switchfire and Borla S Types. Ataks would cause windows to crack.
Interesting. That's how I felt with the Corsa Xtreme without resonators. I knew it was loud but man, I did not expect it that much. I was embarrassed to drive it sometimes lol. Honestly, if I could do it over, I probably would have gone borla atak. My muffler makes an annoying vibration noise when I start up the car. Corsa is so slow to reply as well. It's a headache when the mufflers are only 3 months old.
For what you pay for Corsa, you'd think they'd send a technician to your house. I'm going to take the H-Pipe off my Father in-laws Mach 1 and put the Switchfire on. Put the H-Pipe on my GT. I have a feeling axle backs are made for stock systems wit stock resonators. With H/X res. delete, and axle backs resonators will be needed. Almost got a $1000 lesson taught to me. They'll take the Borla S Types back. Boxes not opened.
