Renntech set out to reverse these restrictions and give the C 63 a power figure to be proud of. An initial ECU software upgrade put the power up to a CLK63 matching 475hp until the tuner had more time to hammer out the engine a little more. This hammering has now been complete with an updated version of its ECU software, RENNtech's stainless-steel long-tube headers and new, track-oriented sound/performance pipes bringing the power figures up to 548 peak horsepower and 510 lb-ft of torque.
Renntech also found time to bang in a height adjustable suspension kit and a new stopping power enhancing braking system.
It'll be interesting to see what kind of performance figures the Renntech C63 is capable of should they decide to release them in the future, however Renntech do tease that an overpowered & 63 monster could make its way through their factory doors for their 20th anniversary celebrations.