Inspired by the winged, unlimited-class rally cars of the famed Pikes Peak Hill Climb, RENNtech set about creating a GLK that could master the pack and leave the rest chewing gravel. But, this wild GLK has a few surprises beneath its menacing exterior.
Hybrid powertrains are generally associated with fuel efficiency and lower emissions. However, RENNtech has taken one more benefit of the hybrid principle to turn the GLK into a formidable performer. By combining an electric motor in parallel with the 3.5 litre V6 petrol engine, RENNtech has been able to capture the impressive torque that characterises electric motor drives, adding 54 Nm to enhance the GLK’s performance off-the-line and out of corners. Using a hybrid drive in a hill climb setting has the added advantage of maintaining thrust at higher altitudes, when internal combustion engines – which depend on ambient air – start to wheeze.
The specialist Mercedes tuning company has also worked its magic on the base 3.5 litre V6 unit, using components from the latest Mercedes-Benz high-performance 3.5 litre V6 Sport engine. These include a special intake manifold, cams and cylinder heads, to which RENNtech has added its own long-tube headers, composite air intake and RENNtech ECU software. Engine output is up to approximately 350 hp, augmented further by the electric motor from the hybrid drive.
The additional 72 volt drive is run by 12 volt plug-in batteries. RENNtech is currently working on a nickel-hydride solution with regenerative charging for additional range.
“The GLK Rally Racer Hybrid is a fully-functioning test bed,” explains Hartmut Feyhl, founder and President of RENNtech. “We will use this vehicle as a proof-of-concept, which we will develop and enhance throughout next year.”
“With the Rally Racer, we have really increased the car’s performance,” continues Feyhl. “Together with the more aggressive, sporting look, we have created a powerful and exciting package.”
It is also worth noting that, despite the performance enhancements, RENNtech has succeeded in improving the fuel economy of the Rally Racer compared with the original version, “proving that high performance and efficiency can coexist,” adds Feyhl.
Bearing in mind that the Rally Racer is built for speed on tough terrain, RENNtech opted to forego creature comforts, cutting the weight of the standard GLK by removing most of the sound insulation and replacing the Mercedes-Benz seats with lightweight carbon-fibre buckets. Engineers also fitted a full roll cage and moved several components towards the rear of the vehicle to create an almost perfect 50:50 front/rear weight distribution for improved handling on tight, demanding rally stages.
Another significant handling modification comes from the custom coil-over suspension. Made to RENNtech specifications by suspension supplier KW, the package allows for adjustments in height, rake, damping rate, camber and toe-in.
Extra stopping power is provided for the Rally Racer courtesy of an in-house RENNtech brake combo featuring massive 412mm, 2-piece rotors with 8-piston callipers at the front, and 356mm discs grabbed by 4-pot callipers at the rear.
Lightweight 20 inch 3-piece, 5-spoke RENNtech wheels in a “Sniper Gray” anthracite finish, clad in NT05 275/40 20 Nitto rubber at the front and NT05 315/35 20 at the rear, fill the prominent wheel flares that underscore this GLK’s performance potential.
Although extensive exterior revisions were made to accommodate the larger wheels and brakes and to widen the track, the focus of bodyshell modifications was enhanced aerodynamic efficiency. RENNtech used the latest in Computational Fluid Dynamics (CFD) software to develop the package. The front splitter, rear diffuser and lower side skirts help direct airflow underneath the GLK Rally Racer to reduce drag and produce added downforce, while improving high speed stability at the rear. The rear wing elements also serve an important aerodynamic purpose and add emphasis to the aggressive edginess of the original GLK design. From a visual perspective, RENNtech engineers successfully melded their aerodynamic modifications with the flared wheel arches to create a powerful side line that highlights the dynamic thrust of the Rally Racer.
“The GLK was a great starting point for this project,” says Hartmut Feyhl, “It has excellent underpinnings for performance tuning and I think the overall look really suits it.”
“The GLK gave us a great deal of scope for bringing together form and function. For the RENNtech GLK, performance may have been the primary goal, but it also looks the part,” he adds.
Even more visually expressive and with an even more elegant and comfortable interior, Mercedes-Benz presents the new GL-Class “Grand Edition”. This distinctive, new special edition of the off-roader comes as standard with a level of spaciousness and comfort that is on a par with a luxury saloon. Features reserved exclusively for the “Grand Edition” designation include special light-alloy wheels with 275/50 R 20 tyres, high‑quality, two-tone leather seats in a new design, and wood trim in black ash. The special Grand Edition model also offers an array of high-quality additional equipment and is available with all the engines in the GL-Class line-up.
The exclusive front end of the “Grand Edition” is unmistakeable: dark-tinted headlamps, a radiator grille with black, high-gloss louvres and a redesigned front bumper with integrated LED daytime running lamps define the special model. Light-alloy wheels in himalayas grey metallic – with a high-sheen finish also available as an option – add further exclusivity. There are other visual highlights too, such as metallic paint finishes, heat-insulating and infrared-reflecting laminated glass all round, aluminium-look running boards with rubber studs, and separated exhaust tailpipe trim.
The interior of the GL-Class accommodates up to seven occupants in comfort with an exceptional level of spaciousness, creating the luxurious atmosphere you would expect from Mercedes-Benz – in this case comparable to the S-Class. For the “Grand Edition”, Mercedes-Benz has refined the interior further, especially through the use of stylish materials. Exclusive appointments include two-tone seats (black/porcelain or black/maroon) in leather (or in nappa leather as an option) with a special piping design and contrasting stitching.
Likewise only available on the “Grand Edition” are door centre panels, armrests and dashboard instrument panel with double-lapped felling, as well as trim and a wood/leather steering wheel in black ash.
Other high-quality appointments: comfort headrests for the driver and front passenger, ambient lighting, roof liner in black designo fabric, velour floor mats with contrasting stitching and “Grand Edition” lettering, “Grand Edition” badge on the centre console, sports pedals in brushed stainless steel with rubber studs and door sill panels in stainless steel.
Powerful and economical engines
The “Grand Edition” models are equipped with PARKTRONIC and any one of the available engines. The V6 diesel engine in the GL 350 BlueTEC 4MATIC utilises highly efficient SCR exhaust gas technology, outputs 155 kW (211 hp) and delivers its maximum torque of 540 Newton metres at 1600 rpm. On average this engine consumes 9.0 litres of diesel per 100 kilometres. In the GL 350 CDI 4MATIC BlueEFFICIENCY, the V6 engine outputs 195 kW (265 hp) and generates torque of 620 Newton metres. It consumes 8.9 litres per 100 kilometres.
Superior power delivery and maximum smoothness are the particular benefits of the two petrol V8 models. These models also comply with the EU5 emissions standard. The 5.5-litre V8 engine in the GL 500 outputs 285 kW (388 hp) and delivers 530 Newton metres of torque. At 6.5 seconds, its acceleration time from a standstill to 100 km/h is almost worthy of a sports car. On the GL 450, the V8 petrol engine has a displacement of 4.6 litres, outputs 250 kW (340 hp) and generates maximum torque of 460 Newton metres. It takes 7.2 seconds to sprint from 0 to 100 km/h.
Agile and safe both on-road and off-road
With innovative 4MATIC all-wheel drive, AIRMATIC air suspension as standard, the accurate Direct-Steer system and the Adaptive Damping System ADS, which also comes as standard, the commanding GL-Class offers impressive handling, guaranteeing excellent ride comfort coupled with outstanding active safety. While the GL cuts an imposing figure on the asphalt, it also has genuine off-road credentials. The modified AIRMATIC air suspension enables ground clearance of up to 307 millimetres. Thanks to its low-range ratio and limited-slip rear-axle and centre differentials, the standard Off-Road Pro technical package opens up considerably more possibilities on challenging terrain. Other electronic dynamic handling control systems such as Off-Road ABS, Downhill Speed Regulation (DSR) and Hill-Start Assist also make life easier for the GL-Class driver.
Prices of “Grand Edition” special models incl. 19% VAT:
In 2008, RENNtech unveiled the GLK350 Hybrid Pikes Peak Rally Car, a concept vehicle which won the 2008 SEMA Show Mercedes-Benz tuner build off competition. This vehicle was designed not only to turn heads as a show car, but to serve as a proof-of-concept and testament to their dedication to a core concept; performance without compromise. Fast forward nearly 3 years, countless automotive trade shows, numerous track events and extensive real world miles; the GLK Pikes Peak project has been completely revamped and restyled for a final tour in 2011 with Mercedes-Benz USA.
Upon completion of the US tour schedule, the GLK will retire to a place of honor in the Mercedes-Benz Classic Vehicle Museum located in Irvine, CA as part of their permanent collection. This will be the second vehicle prepared by RENNtech that has found its way into the hallowed halls of the Mercedes-Benz Museum Collection, the first of which was the E60 RS project car built for comedian Jerry Seinfeld.
When approached with the opportunity, RENNtech completely revamped the vehicles exterior and collaborated once again with 3M Commercial Graphics Division to complement the GLK’s aggressive exterior styling. This original body kit was entirely designed and engineered by RENNtech in-house, using the latest in Computational Fluid Dynamics (CFD) software and rapid prototype capabilities. The concept behind the restyling was to not only completely change the vehicles appearance, but utilize vinyl materials in finishes rarely seen in the automotive world. 3M chose the RENNtech GLK as the showpiece to revel their latest product line of 1080 Scotchprint ® textured automotive vinyl wrap. This preprinted, 3.5 mil dual cast film was applied to nearly every exterior surface of the vehicle in a stunning combination of brushed steel (1080-BR201) and black carbon fiber (1080 CF-12) with subtle red pin stripping to further accent the vehicles bold lines.
The GLK350 Pikes Peak Project was unveiled to the public during Mercedes-Benz’ first leg of their tour schedule at the Pittsburgh International Automotive Show February 10-13th, 2011. Additional stops on the tour schedule include Milwaukee, Cincinnati, Cleveland, Kansas City, Minneapolis and Denver. After its time on the road, the vehicle can be seen at the Mercedes-Benz Classic Vehicle Museum in Irvine, California.
RENNtech worked with and was supported by several companies that can be seen below.