 |
   |
|
|
Mean Green is a unique hybrid truck built by an enthusiastic team at Volvo Trucks. They plan to use it next spring to beat the world speed record for the standing kilometre. Behind the wheel is Swedish truck racing ace Boije Ovebrink. "The absolute elite among Volvo’s hybrid technology experts are the driving force behind the project. They are true enthusiasts, every last one of them. I’d go so far as to say that Mean Green is the world’s fastest hybrid truck," he says. To understand how he can make this claim with such confidence, we need to rewind to November 2007. Boije Ovebrink had just beaten his own standing kilometre record from 2001 for trucks with a maximum displacement of 16 litres. He achieved this by reaching an average speed of 158.829 km/h with his red Volvo NH16, a.k.a. The Wild Viking. After winning, he met Staffan Jufors, president and CEO of Volvo Trucks, who asked him: "Do you plan to sit down and twiddle your thumbs now, enjoying the fame that comes with being world champion, or do you have any new ideas?" Ovebrink replied: "I'd like to build the world's fastest hybrid." "The idea met with approval, but at the time I had no idea about the fantastic technology Volvo had in the pipeline," recalls Boije Ovebrink. Planning for the hybrid got under way. Suddenly, however, a Czech truck racing team claimed they had beaten Ovebrink's record. Order had to be restored, so that spring, Volvo engineer Olof Johansson got down to some serious work. He started building a truck that could retake the record but that could also be reconfigured for the planned racing hybrid driveline. That truck is now called Mean Green. But the team decided not to install the hybrid driveline straight away. "I started building the truck from two half frames that had been earmarked for the scrapyard. And the American VN cab came from a crash-tested chassis whose cab was totally intact," Olof Johansson explains. Weight reduction was absolutely crucial to setting new records. For example, the front axle was milled by experts from Volvo's engine factory in Skövde and lightened from 100 kg to 57 kg. And the gear set for first gear was removed from the gearbox, shaving off another 7 kg. "I slit open the wiring harnesses and removed unnecessary wiring. That slashed almost six kilos," says Mr. Johansson. Boije Ovebrink was also ordered to lose weight. "They made me promise to lose 20 kilos, and so far I'm half-way to my target," he says. Designer Jonas Sandström at Volvo put in many hours with his CAD program to come up with the optimal aerodynamic shape. "It's important that the wind breaks away from the bodywork in the right way. Our truck differs from a Formula 1 car, for instance, in that the aerodynamic properties allow the truck to slice through the air rather than be pressed down onto the road surface," he explains. Just a few days before the assault on the record, it was announced that FIA, the international motorsport organisation, had disallowed the Czech team's result. Still, there was no need to cancel the planned attempt on the record. Ovebrink and the Volvo team were aiming to further improve on the 2007 record. And on June 9, 2010 they did just that. The new world record for the standing kilometre was set at a two-way average speed of 166.7 km/h. Top speed was in the region of 260 km/h. Once this was achieved, focus reverted to what the entire project had been about from the very outset. The truck already had a standard Volvo 16 l engine with twin turbos from Volvo Penta and other equipment delivering a massive 1900 hp. The truck retained that unit. However, the lightened Powertronic auto-shifter was replaced with a modified version of Volvo's automated I-Shift gearbox so that the transmission could interact with the component that makes Mean Green a hybrid - its electric motor. "This gives an additional 200 hp and 811 lb ft of torque. The result is a lightning-speed boost from start-off without any of the customary diesel-engine delay. It's like a champagne cork, but without the sound effects. For the first couple of seconds, the truck just makes a slight whistle until the diesel engine, which runs on renewable liquid rosin diesel, starts delivering with explosive force - by which time the truck is already doing 60 km/h and I can engage ninth gear," explains Boije Ovebrink. When is Mean Green going to make its bid for the standing kilometre record? "In November we'll test race it at Volvo's Hällered proving ground to see what it's capable of. As soon as the winter snows disappear early next spring, we'll set our record." The standing kilometre
|
|
© InfraStructures - Tous droits réservés - All rights reserved |
Mean Green Hybrid
