Volvo reveals fastest hybrid truck
Volvo Trucks has unveiled to the word its Mean Green technology demonstrator – a unique hybrid truck that the Swedish OEM plans to use next year to beat the world speed record for the standing kilometer.
“The absolute elite among Volvo’s hybrid technology experts are the driving force behind the project,” says Swedish truck racing ace, Boije Ovebrink, who will pilot the Mean Green during its attempt to shatter the world record. “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.”
Three years ago, Ovebrink had beaten his own standing kilometre record for trucks with a maximum displacement of 16-liters – a record that had stood since 2001. He achieved this by reaching an average speed of 158.829km/h with his red Volvo NH16, which was nicknamed the Wild Viking. After setting a new level, he met Staffan Jufors, 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 truck.”
And the rest, it would seem, is history. “The idea met with approval, but at the time I had no idea about the fantastic technology Volvo had in the pipeline,” he recalls.
Planning for the hybrid got under way, but 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. Even at that early stage, the truck was to be 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 scrap yard and the American VN cab came from a crash-tested chassis whose cab was totally intact,” he 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, Sweden and reduced from 100kgs to 57kgs. Then the gear set for first gear was removed from the gearbox, shaving another seven kgs off.
“I slit open the wiring harnesses and removed unnecessary wiring. That slashed almost six kilos,” says Johansson.
Ovebrink was also ordered to lose weight, as he recalls, “They made me promise to lose 20kilos and, so far I’m half-way to my target.”
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 the FIA 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 166.7km/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. “Olof immediately went on the offensive. The very same day the new record was set; he pulled out his toolbox and started modifying the truck to build what we see today – a thoroughbred hybrid.”
The truck already had a standard Volvo 16-liter 700bhp engine with equipment including twin turbos from Volvo Penta. It was a powerplant delivering a massive 1,900bhp. 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 200bhp and 1,100 Nm of torque. The result is a lightning-speed boost from start-off without any of the customary diesel-engine ‘lag’. 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 60km/h and I can engage ninth gear,” explains Ovebrink.
So, when is Mean Gree’ going to make its bid for the standing kilometre record? “This November we’ll test race it at Volvo’s Hällered proving ground to see what it’s capable of. Then, as soon as the winter snows disappear early next spring, we’ll set our record.” says Ovebrink, confidently.
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