The horsepower wizards over at RENNtech have focused their wrenches on the already potent Mercedes-Benz C63 AMG to create what they consider to be a fitting heir to the Mercedes 6.3, appropriate given the name and the fact that latest C-Class has grown nearly to the size of that legendary sedan. To achieve this proper Überness, they’ve released the 6.2 AMG V8 from the grips of unnecessary restriction and managed to squeeze out nearly 100 additional horsepower. The sleek sedan achieves up to 548 HP and 510 lb-ft of torque thanks to new engine management, long-tube headers and new pipes. To handle all of that extra power you might want to opt for the new RENNtech brake kit and, just to be safe, throw in the height control suspension system for some up and down goodness and you have yourself one mean machine. Full details in the release below the jump.

RennTECH Tuned Mercedes-Benz C63 AMG

40 years ago, the hottest, fastest sedan you could buy was Mercedes-Benz’ 300SEL 6.3. By placing its largest engine in a mid-sized car, Mercedes’ engineers created a luxurious sedan capable of out-performing some of the quickest sportscars of its day. The 6.3 remains a landmark sports sedan that continues to influence Mercedes’ design direction. Nowhere is the influence of the 6.3 more evident than in AMG’s current line of sports sedans. AMG’s newest cars carry the first purpose-built, “all-AMG” engine design in the company’s history, and the “63″ designation they wear (S63, E63, etc.) is a direct reference to the 6.3.

Last year, Mercedes revisited the “bigger engine, smaller car” formula and introduced the C63 AMG. Powered by the same 6.2 liter V8 as its bigger, more expensive S and E class siblings, the C63 promised heart-stopping performance at a bargain price … but, somewhere between concept and production, something happened: the C63 put out a “mere” 451 hp.

While the C63 is certainly no slouch, it didn’t make the same 507 or 518 horsepower that its E and S class siblings made. Some of the power difference can legitimately be blamed on more restrictive intake and exhaust paths – after all, the big V8 is a tight fit in the smaller C class, but this fails to explain how the same engine, when found under the hood of a CLK63 AMG Cabrio, makes 475 hp.

Where did that 24 hp go?

“Mercedes restricted the car,” explains Hartmut Feyhl. “So, our first step in extracting more power from the C63 is to de-restrict the car.” Of course, in this modern age of software encryption and electronic obstacles, that kind of “de-restricting” is easier said than done – which is why Feyhl is exactly the man you want to talk to when it’s time to take your C63 to the next level.

Hartmut Feyhl was technical director at AMG North America before forming his own company, RENNtech, in 1989. Since then, Feyhl built a reputation as one of the world’s premier tuners and America’s foremost authority on Mercedes-Benz high performance.

It should come as no surprise, then, that RENNtech’s first offering for the C63 was an effective ECU software upgrade (ECU1) to unleash the same “factory” 475 hp and 465 lb-ft (up from 451 and 443) as the CLK.

It should also come as no surprise, then, that RENNtech didn’t leave it at that! “In a sense, the C63 is a return to the roots for Mercedes, and for AMG, and also for RENNtech,” says Feyhl. “It is a very special car, as the C class has grown to about the same size as the 6.3 and the W124 Hammer, but with much more power. We want to see how far we can go with this car.”

With that in mind, RENNtech has introduced a comprehensive line of performance products to turn the AMG C63s of the world into more focused trackday performers, starting with the car you see here.

To get the most from the C63, RENNtech began with the ECU2 high-performance software. Much more than a (relatively) simple de-restriction, this flavor of RENNtech’s software optimizes every aspect of engine performance, building massive amounts of torque across the low-to-mid rpm range and boosting the C63’s top speed to 187 mph. When combined with RENNtech’s stainless-steel long-tube headers and new, track-oriented sound/performance pipes, the RENNtech software produces 548 peak horsepower and 510 lb-ft of torque.

RENNtech sharpens the C63’s handling reflexes with a fully adjustable sport suspension and adjustable front and rear camber bushings that allow customers to “dial-in” ride height and shock damping while the camber bushings help maintain proper camber and alignment for maximum grip (RENNtech considers these camber bushings a must-have item for serious performance drivers).

To rein in the C63’s newfound horsepower, RENNtech offers maximum stopping power in the form 15.2″ 2 PC rotors clamped by RENNtech calipers. Along with stainless steel braided lines front and rear, these brakes improve overall feel and driver confidence at speed. Additional cooling from RENNtech’s carbon-fiber brake ducts further reduce fade – another must-have upgrade for competitive driving styles.

In the past, few would have considered a car like the C63 a truly capable trackday ride, but with the success of track events like the AMG Challenge and SLR.Club Trophy, it is clear that there are a growing AMG drivers who want to experience their car on the track. “We are all racers,” says Feyhl, “and when we find ourselves on a track, we want to be competitive.”

With nearly 100 hp over the stock C63 AMG, the RENNtech-tuned C63s will probably be powerful enough for most people – but remember that this is RENNtech! The birthplace of the “real” 722 SLR, where a 900 lb-ft twin-turbo V12 sedan is a daily occurrence. Plus, 2009 marks RENNtech’s 20th anniversary … does Herr Feyhl have some kind of “birthday party” in mind for RENNtech that involves the C63 and ties all this rich history and tradition together?

For most people, the abundant power and superb handling of the amazing Mercedes-Benz CLK63 AMG Black Series is more than sufficient. Straight from the factory, the CLK 63 Black boasts an output of 373 kW/507 hp and 630 Newton meters of torque – enough to propel the CLK from 0-62mph in just 4.3 seconds and reach its electronically-limited top speed of 186 mph easily. But there’s more than that! There’s the high-performance brake system, the track-optimized adjustable threaded suspension, the specially-developed cooling systems… the list goes on… But, for those of you whose always looking for more, the nice boys at Renntech have introduced a tuning package for the CLK 63 Black Series – one that extract a bit more power and drivability from an already supremely capable vehicle.

The magicians at Renntech have managed to increase power output of the CLK63 AMG Black Series to 550 horsepower, and even more impressive, they’ve also managed to deliver an additional 45-60 lb-ft of torque between 2400 and 5000 rpm. According to the founder of Renntech, Hartmut Feyhl: “Real-world performance is all about torque, not so much about a peak horsepower number at very high rpm. It can be very easy to build high rpm horsepower, but to get instant throttle response and mid-
range acceleration it is more difficult, and this is where customers really want to feel that improvement.”

But again, there’s more than just engine power to look at. Next, the CLK63 Black Series’ handling was tweaked. Renntech has somehow lowered the car an extra 3/4″ and added carbon-fiber strut braces and fully-adjustable camber bushings at all 4 corners. But wait, there’s more! To improve aerodynamic efficiency, an adjustable carbon fiber rear wing and a front splitter/rear diffuser combination were added, and completing the package are some high performance brake pads and stainless-steel braided lines (ensuring an ample amount of stopping power, should the need arise).

While Renntech’s tuning package isn’t necessary to experience the thrill and exhilaration in your CLK63 AMG Black Series, it is a nice and simple way to experience more of what your dominating Mercedes already provides.

Additional photos of the Renntech Mercedes-Benz CLK63 AMG Black Series and the full press release from Renntech are below.

OFFICIAL PRESS RELEASE

RENNTECH for the Mercedes-Benz CLK63 AMG Black Series

Mercedes-Benz made a big splash with the introduction of its CLK63 AMG Black Series coupe last year. The aggressive “F1 safety-car” look gave the 500 hp CLK
Black a visual edge that the CLK55 AMG lacked, and the Black Series’ suspension and brakes were in a decidedly different league compared to other Mercedes.

Impressive spec sheet notwithstanding, some customers will still believe that 500 hp is not enough, and for those select few who find the CLK a bit tame, there is always
RENNTECH.

Established in 1989 by Hartmut Feyhl (ex technical director: AMG North America), RENNTECH quickly made a name for itself with high-powered magazine tuner-
shootout cars that were reliable enough to actually be driven from RENNTECH’s home in South Florida thousands of miles to events in Texas and Michigan. For
the CLK Black, Feyhl told his crew to develop the same kind of “real-world” performance upgrades that made his cars so famous to begin with.

“Real-world performance is all about torque, not so much about a peak horsepower number at very high rpm,” explains Feyhl. “It can be very easy to build high rpm
horsepower, but to get instant throttle response and mid-range acceleration it is more difficult, and this is where customers really want to feel that improvement.” To build
that improvement, RENNTECH adds long-tube headers and a motorsports style exhaust to the already-potent 6.2 liter engine, tying it all together with RENNTECH’s own
ECU software, sharpening throttle response and boosting 550 peak hp. The real story, however, is drivability – and this is where the RENNTECH tuning package shines,
delivering an additional 45-60 lb-ft of torque between 2400 and 5000 rpm.

To “sharpen” the car even further, RENNTECH fine-tuned the CLK63 Black Series’ suspension, lowering the car 3/4″ and adding carbon-fiber strut braces front and rear. To
enhance mechanical grip in fast corners, RENNTECH also added fully-adjustable camber bushings at all four corners. Aerodynamic stability is also greatly enhanced with an adjustable carbon-fiber rear wing element and a front splitter/rear diffuser combination to manage underbody airflow, building usable downforce and (adjustable) aerodynamic balance at speed, while directing cooling air to the Black Series’ huge AMG brake rotors – themselves enhanced with high-performance pads and stainless-steel braided lines. The result is a hard-core CLK63 from RENNTECH that does the unthinkable: it makes the standard CLK63 seem a bit soft.

Copyright © 2008, Renntech