C63s catback question




As for the Zac parts.... ummm... I guess I don't mind recommending them, especially for the price and that you get a complete cat-back exhaust, not just axle-back. The fitment was "okay", but when I contacted Zac about the fitment issues I experienced they made it right and sent me replacement parts (hence the reason I have both an H and X center section)... so they seemed to stand by their product.
If you go with the Zac exhaust, you will have to extend the wires for both of the rear exhaust valves (something that isn't mentioned on their website), and the rear muffler hangars took some modification and re-welding to fit like the factory ones. Lastly the ball and socket flares at the joint where they mate with the Modal Works downpipes were a little off on the first set I got (Zac flare was bigger than the Modal Works socket - so the clamp wouldn't hold / seal)... but that is probably because of the different manufacturers. I was able to modify the flare and make it work, and the second center section Zac sent me didn't have the same issue.
Last edited by Roysup; Dec 1, 2025 at 05:04 PM.
Here's a Link
As for the Zac parts.... ummm... I guess I don't mind recommending them, especially for the price and that you get a complete cat-back exhaust, not just axle-back. The fitment was "okay", but when I contacted Zac about the fitment issues I experienced they made it right and sent me replacement parts (hence the reason I have both an H and X center section)... so they seemed to stand by their product.
If you go with the Zac exhaust, you will have to extend the wires for both of the rear exhaust valves (something that isn't mentioned on their website), and the rear muffler hangars took some modification and re-welding to fit like the factory ones. Lastly the ball and socket flares at the joint where they mate with the Modal Works downpipes were a little off on the first set I got (Zac flare was bigger than the Modal Works socket - so the clamp wouldn't hold / seal)... but that is probably because of the different manufacturers. I was able to modify the flare and make it work, and the second center section Zac sent me didn't have the same issue.
Thank you for the detailed response! Your car sounds great! This has definitely got me thinking as I originally wanted the x pipe to change up the sound, but now I may stick with the H pipe.





