Just half a year is left before the start of “Dakar-2016”. KAMAZ-master team presented sport truck with conventional configuration when works on preparation for the main start of the off-road racing season are in full swing.
Decision on building a new truck was made based on rising tendency to use conventional (bonneted) trucks in off-road racing.
Background
Looking back at the history, one must admit that Mercedes Unimog, built by Daimler-Benz, was pioneer in using bonneted truck in off-road rally, and it successfully turned in a good performance during Paris-Dakar motor rally in 80s of the twentieth century. But not powerful engine, short wheelbase, and too small for three people cabin didn’t let it defy competition in the future.
Amongst pioneers that used bonneted racing vehicles are Ukrainians, who in the beginning of 2000s presented a project of two-axles racing KRAZ which remained only at a project state.
Czech Ales Loprais and Dutch Gerard De Rooy are the real pioneers in using bonneted vehicles, both followed in footsteps of their famous sports ancestors. The first Tatra Jamal driven by Ales Loprais made first appearance in 2011 “the Silk Road” rally raid, and in 2012 already two trucks with conventional configuration participated in Dakar race – the said Tatra Jamal and IVECO Powerstar Torpedo driven by Gerard De Rooy.
Participation of those two vehicles in Dakar rally in 2013-2014 clearly confirm their advantages over cab-over-engine trucks, and in 2015 already 4 bonneted trucks participated in Dakar, and in 2016 it is planned to have even more trucks of conventional configuration participating.
Benefits of bonneted configuration:
Mass and load is distributed across axles
Since for both cab-over-engine and bonneted trucks the engine location and gear box location regulations are the same and are defined by the distance of engine and gear box joint point location, that distance must not exceed 1400 mm fr om the front axle, and so shifting the cab with crew of gross weight around 800 kg by 1,5 meter towards the back of the truck definitely increases load on the rear axle up to 55-56%.
Load relief of the front axle and bigger load on rear axle significantly improves movement on sand, ensures better landing when performing leaps.
Shifting center of mass towards the center of the truck also improves truck maneuverability and provides advantages when moving across weaving and speedy sections.
Vehicle steering\driving
Driver sitting next to center of mass significantly improves control of the vehicle, compared to sitting “on the wheel”. More than anywhere else this advantage is exercised on rally special stage sections, wh ere control over vehicle behavior and its orientation in space plays critical role.
Comfort
The notion of “comfort” regarding racing trucks hardly can be applied in the full meaning of this word, it’s better to say that it is acceptable conditions for the crew to survive two week long race across off road surfaces and to perform their functions.
Due to cab is located almost in the center of wheelbase, the crew of the bonneted truck experience a lot less of vertical loads and impact, than cab-over-engine crew who is sitting right on top of the front axle.
Real life experience shows that off-road speed of the truck depends greatly not only on suspension configuration and vehicles ability to sustain extreme loads, but as well on the physical abilities of the human being no matter how well trained he is.
Changed configuration requires extensive change of number of systems and aggregates.
First of all, the engine. Due to shift of the cab towards the back, the engine located right underneath the cab, the wide V-engine used by KAMAZ, simply leaves no space in the cab for the crew. This is why for bonneted trucks only R-engines are used.
Secondly, engine cooling system and turbocharging system. Bonneted vehicles due to shifted to the back cab doesn’t allow place heat exchange units of charged air separately from water radiator, hence significant changes in entire cooling system are required.
Thirdly, accessibility of the engine and its systems to perform maintenance and repairs. In this regard bonneted vehicles require some special solutions.
Having clear understanding, that tuning of large quantity of new aggregates and new technical solutions will require a lot of time, KAMAZ master made a decision to build bonneted vehicle with maximum use of already ready and tuned aggregates and components.
In autumn 2013 management of KAMAZ and Daimler came to decision to build bonneted racing truck on the base of Daimler Zetros cabin, having previously shared experience of building trucks together.
The other important point was selection of suitable engine. Since development of in-house 6 cylinders engine in cooperation with Liebherr is yet at the stage of refinement, and its mass production will start approximately in year and a half time, there was an agreement made with Czech company Buggyra to lease prepared sport engine Caterpillar, which while being used by other teams has already proved itself worthy during Dakar race.
Chassis of KAMAZ-4326 was used as chassis for the prototype, it has many times been tried and tuned during Dakar rally.
The objective of development and building of the bonneted racing truck prototype is carry out live test under real off-road rally conditions to evaluate benefits of such configurations, to tune up new aggregates and systems, and to come up to a decision whether it’s reasonable to use such type of the truck in the future competitions or not.
Vladimir Chagin: “New bonneted vehicle project from KAMAZ-master has been suggesting itself for a long time, and was well expected. Many of our main competitors are using vehicles of such type during off-road races. Competition in truck standing is fierce and intense as it is. I think appearance of bonneted KAMAZ will attract even more attention to the race, and no doubt will become its adornment”.