liter V6 hybrid
approx 350 hp
approx 100 hp per liter
Press Release) RENNtech: The GLK Pikes Peak Rally Racer is
king of the hill
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
“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
“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
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
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.
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.