Mercedes CLS GTR: A Work Of ART

Motoring Channel Staff - 11/Apr/2006

The stately Mercedes CLS-Class quasi coupe is one of the German prestige marque's nicest looking vehicles, with a subtle style that seems to emanate style and exclusivity. 

But that doesn't mean that it can't be transformed into a ballsy, take-no-prisoners GTR replica, courtesy of one of Germany's growing tuning outfits, ART.

Based in Nuremburg, ART's new GTR is built upon the CLS model, either the CLS 55 AMG or the CLS 63 AMG, both of which are vehicles that would be more than powerful and agile enough for most drivers.

For example, in its original form, the 5.4-litre supercharged CLS 55 AMG generates 350kW of power (469hp) @ 6100rpm and 700Nm of torque @ 2650rpm, which is enough to propel the vehicle to 100km/h from standstill in 4.7 seconds. That kind of performance is enough to make an HSV quiver with inferiority.

But for some drivers even this kind of performance is not enough, and with the aid of some engine and exhaust system tuning, the GTR 560 (based on the CLS 55 AMG) increases output by 68kW to 418kW, while torque rises from 700Nm to 790Nm. These significant power and torque increases shed a decent 0.3 seconds off its 0-100km/h time, down to 4.4 seconds.

Matching its increased power output, the GTR 560 (named so because of its 560 horsepower output, as opposed to the GTR 620, which will get to later) is the beneficiary of a number of aerodynamic upgrades, evidenced in the photos. There's an overall increase in the body shell's width, and the car gets a highly provocative bodykit that comprises of aggressively styled front and rear aprons. The front end also gets a lower lip spoiler and distinctive double fog lamps, and a 'Lamella' grille that omits the Mercedes-Benz three-pointed star.

At the rear, the car displays an almighty rear wing, while the brake lights remind somewhat of the late 1990s Australian AU Ford Falcon. Further down the rear end, the modified CLS models brandish a quartet of big bore exhaust pipes, which combine with what ART calls an "integrated diffuser" and the rear wing to create an inspired race car look.

Art calls the GTR model a "sports tool with brilliant performance" and this relates to its handling abilities, and not just its accelerating performance. 

Packing a specially modified chassis, the new GTR 560 and GTR 620 sit on daunting 20-inch alloy wheels shod with 255/30 ZR20s at the front and 305/25 ZR20s at the rear. The GTR models are also much wider than their CLS donor cars and will be therefore be more at home on the racetrack, increasing width by 70mm and 80mm front and rear respectively, while electronically adjustable ride height can instantly alter the cars centre of gravity. 

Getting back to the big daddy model based on the CLS 63 AMG, which is powered by Mercedes newer, but naturally aspirated, 6.3-litre V8 engine. In it's AMG-tuned guise the 383 cubic inch engine generates 514 brake horsepower, or about 383kW of power, while the fettled GTR 620 ups power levels significantly thanks to the use of a stainless steel sports exhaust system and other undisclosed engine mods that are currently "still in the development process" according to ART. One imagines the camshafts would be new, as would perhaps the cylinder heads, ECU and fuel injection mapping.

Either way, the power rises from 383kW to 463kW, or 514bhp to 620bhp, which is a massive jump and enough to stir the hulking modified Mercedes into instant action. This also drops the 0-100km/h sprint time by 0.3 seconds, taking the dash to a flat 4.0 seconds, with a top de-restricted speed expected well beyond the 300km/h mark. ART also notes that the GTR 620 version will be its 'export' model, so it's likely that only European customers will have access to the slightly slower supercharged GTR 560.

Completing the transformation from AMG sports car to GTR road-going race car is the interior, with which ART has added a rather surprising, yet alluring feature. In addition to new interior trimmings featuring leather, carbon fibre and more leather, the GTR models also get "steplights" on the sills, essentially blue LEDs spanning the sills which give the car a futuristic look and feel as the doors are opened (see image below). Furthermore, owners can even have their initials stitched into the velour carpets while far less intriguing appointments include the sports steering wheel and gear shifter.

The hyper sports cars, both featuring huge amounts of V8 power, are expected to be available to European customers this month (April '06) with other territories, such Asia Pacific and possibly the Americas, to follow later with the GTR 620.