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May 7, 2012

Mean Green Volvo Sets World Record – 147 mph

At Wendover Airport near the Bonneville Salt Flats, Swede Boije Ovebrink powered his hybrid Volvo VN race truck Mean Green to a new world record for the standing start km and established a record for the flying km for hybrid diesel trucks.

Running Friday, April 27, in modified diesel, class C (trucks over 1,000 kg), Mean Green ran 147.002 mph in the flying km, and 95.245 mph in the standing 1 km, establishing two new world records. Additionally, it ran a 22-mph flying km under electric-only power, using the 200-hp motor that is part of the truck's parallel hybrid system to prove it really is a hybrid. These world records were officially timed to seven decimal places by world-class timing crew ChronoLogic under the watchful eye of David Petrali of the United States Auto Club, the sanctioning body for the FIA (Federation Internationale de l’Automobile), the governing body for all autosport world records.


Mean Green is a joint engineering effort between Ovebrink and Volvo AB of Sweden. Volvo engineers cooperated on the design and construction of the record-breaking VN, which is powered by a 1,900-hp, 16-liter, D16. The extra 200 hp of the electric drive means the truck has 2,100 hp available to accelerate or push top speed. The North American VN was chosen as the basis for the record-breaker for its aerodynamic shape.

As part of the race entourage, Ovebrink has a European 6x2 Volvo FH16 tractor powered by the same 16-liter engine, though at a peak highway rating of 750 hp. The highly sophisticated race truck hauler is a handsome tandem axle trailer by specialty Swedish manufacturer SpecialKarosser AB (KRAB).

The whole outfit was shipped from Europe for the world record attempts at the WWII airfield in Wendover, UT. This historic airfield – the trucks were staged in the hanger where the atomic bomb Little Boy was loaded aboard the B-29 Superfortress Enola Gay – was used as the neighboring Bonneville Speedway was not yet sufficiently dried and ready for speed trials. As part of its North American tour, the race truck made an appearance at the recent Mid America Trucking Show and the Canadian show, Truck World; and will appear in Miami, at the Volvo Round-the-World Ocean Race in May.

Although Mean Green is a highly technical truck, Volvo Truck NA Manager of Product Marketing, Ed Saxman says, most of the components are production pieces that were highly modified. The engine, for instance is basically the same as the unit in the highway hauling FH16 cabover but fitted with Mahle racing pistons, and using Volvo Penta marine camshaft, electronic controls and fuel mapping, and intercoolers for the two-stage series turbocharging to make 1,900 hp.

Up behind this monster motor is a race-type Sachs ceramic clutch to contain the massive 3,700 foot-pounds of torque. Next in the powertrain is the 200-hp electric motor/generator that comes from the Volvo Bus side and is similar to the unit that is used in the new generation big red double-decker buses that are a common sight on the streets of London, England. This is partnered with an electronic controller programmed for the special speed requirements with a liquid-cooled Lithium Ion battery pack.

The transmission is an I-Shift automated mechanical transmission that is likely the only transmission that can handle the combined engine and motor output. It has special controls that snap the shifts through and get back on the power as quickly as possible. In racing, Ovebrink says he uses a skip shift progression, starting out in 8th gear for the flying record and 6th gear for the standing runs, using full hybrid boost to get the truck rolling, then 9, 11 and the transmissions top 12th ratio.

The single drive axle is another modification. Normally it is used as a double reduction axle with the first reduction using 1.85:1 gear ratio, then hub reduction of around 3:1 at the axle ends. Except on Mean Green, there is no hub reduction so the axle is a very tall 1.85 ratio.

Brakes are standard Volvo air discs. There's no parachute to drag the speed down at the end of the run as the VEB engine brake coupled with the regenerative feature of the hybrid system drags the speed down and recharges the batteries ready for the second run.

Under FIA rules, a record run consists of two passes through the measured distance in different directions. The top speed for the flying km was lower than predicted for a couple of reasons: Normally, there's 1 km either side of the measured distance for acceleration and braking, but at the Wendover field there was only room for 700 m of acceleration. Ovebrink said he was coming into the traps at 225 km/hr (140 mph) still accelerating where he normally would see 250 km/hr 155 mph). The other issue is the altitude at Wendover – 4,340 feet. So far, most Mean Green demonstration runs have been closer to sea level and altitude always negatively impacts performance.

Nonetheless, Ovebrink and Mean Green came away establishing a world record for hybrid trucks and a new standing-start km record, as well as the electric-only record. He was congratulated with a dousing from the Gatorade bucket, brought along to mark the accomplishment.

Red-Hot Ride in Mean Green.
Once the records had been set, it was time for some fun, and journalists and dignitaries along to mark the event got the opportunity to ride in the truck. Dutifully, I donned the crash helmet and strapped in to the five-point seat belt for the wild ride. The door closed with a clang – there’s not a shred of sound proofing in the VN cab! Pulling away, Ovebrink juggled with the shifter, steering wheel and push-to-talk button for the in-helmet communications with his crew. The noise was not unbearable but the ride was firm and then BAM, the first shift went through. To say this was a shock is truly an understatement. This is no soft-shifting highway controller that usually accompanies the I-Shift.

We rolled out to the start point for the acceleration, turned to look down the strip and Ovebrink nailed it. The tires squealed – they're specially made Goodyear ultra-low profiles with tread made from super-sticky motorcycle race compound – and we charged off the line. The first full power gearshift came up, the chassis, which was all torqued up, leveled out for an instant and the shift completed with a solid thump in the back. Then we took off again.

Acceleration felt like sitting on the doorstep of a house as it goes off a cliff. There's a colossal push in the back, the horizon seems to lean over as the frame torques up and the speed goes climbs. Ovebrink was asked not to go overboard on these rides so he backed out of it at around 225 km/h (around 140 mph) and we cruised for several hundred yards before using the regenerative braking to slow for the exit point. Then we sat for a few minutes while the batteries charged some more and he could demonstrate the acceleration under electric power alone.

This is an important feature for Mean Green as the electric motor makes its peak torque when it is stationary – at stall. So off the line, this motor is a big help in the first few hundred years as the clutch engages and the engine rpms rise into the diesel's peak torque at around 1,000 rpm. Then the electric motor and diesel work together.

We got back to the staging area and I reluctantly climbed out after unsnapping the belts and wriggling out through the heavy roll cage. That was a wild ride!

Cool Ride: Mean Green Transporter
A much more comfortable ride with far less drama was available the night before the event. I went out on a photo shoot of the race car transporter and was able to get behind the wheel of the big FH16. This is the top of the line in Europe where cabovers dominate because of length laws. (Other dimensions differ there too, most noticeably in gross combination weights that can be up to 44 tonne (97,000 pounds) in mainland Europe and 60 tonne (130,000 pounds) in Scandinavia. Hence the available 750-hp rating. Nothing less could haul Mean Green.

Needless to say, with its I-Shift transmission and 2,250 pound-feet of torque, this transporter combination was effortless to drive. In fact, it was wonderful – just like coming home – to be back in a cabover again, sitting out there by the driver’s door, riding high (there are four steps to get up into the cab, and there’s no way you can see the floor til you've at least mounted the first step).

The fully suspended cab just floats, mechanical noise is left behind and the trailer, with its 72-inch kingpin setting and forward-mounted axles just tracks along behind the tractor so you can cut the corners as tight as you want.

It was a “died-and-gone-to-heaven” driving experience.




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