To stiffen things up, ACG installed KW Variant 3 coilovers and custom Swift springs. And to shave weight, they replaced the stock hood and trunk with VIS carbon pieces. A EUROteck carbon front lip and Vorsteiner carbon trunk spoiler both help to reduce lift.
All the paintwork was expertly handled by Chapparone Auto Body, which included some surprisingly subtle red pinstriping. They also left some exposed carbon sections to highlight the weave underneath.
Inside, every surface has been re-done: the headliner and pillars covered in black suede, the dashboard and center console in leather with red stitching. MA Carbon pieces cover the doors, console, steering wheel and it uses their carbon shift paddles.
The front seats have red leather centers and AMG embroidered on the headrests, while the seatbacks have RevoZport carbon covers.
The audio system was also taken to the nines. Built around a TRU Technology Super Billet SB8-8 amplifier, it has a 12" Image Dynamix sub and Focal speakers all around. The system adds about 175 lb but the weight was kept low and near the wheels and act as ballast to keep the rear tires planted.
As good as the sound system may be, the angry bellow from the long-tube MBH stainless headers, ACG link pipe and Akrapovic exhaust sounds even better. Sonically, it hits the sweet spot without overwhelming you. Distinctive at every RPM, you shift by listening to the tone.
Stage 2+ has a higher-pitched supercharger whine than Stage 1, but the faster-spinning supercharger means throttle response is noticeably sharper than the car we drove last year. Just the slightest nudge on the pedal will send the tacho needle soaring.
There’s pinned-to-the-seatback power from early in the rev range, and it builds quickly before riding a lofty plateau near the 700whp threshold. There doesn’t appear to be a noticeable drop-off as you pull the paddle for another gear, with each cog dispatched in what feels like a nanosecond.
The wide rear tires make the car feel planted and stable under hard acceleration, although credit should also go to the Quaife LSD as well as KW’s V3 coilovers. However, at times when we were in the 120s, the car started to wriggle as it tried to maintain composure over the small bumps and dips being thrown its way.
In the corners, turn-in was crisp as the body remained flat, reminding us of the CLK Black Series in its ability to control more than 4000 lb. Through mid-speed esses, the car was very stable, practically begging you to go faster.
We can debate whether this is the best C63 ad infinitum. Brabus and its 800hp C-class coupe or Bullit sedan would be the most tantalizing head-to-head match-up, but unfortunately we don’t know of one in the US.
That said, ACG’s C63 gets high marks for execution, and we’ve yet to drive another C63 with such devastating acceleration or composure in the corners.