Mean machines 08 June 2010

With the British truck racing championships well underway, Brian Tinham talks to leading talent Stuart Oliver about the engineering behind the action

Truck racing is nothing short of awesome. It's like Formula One for giants on steroids – with a raw energy, thunder and sheer muscle you just don't get from anything weighing in at less than 5,300kg being ragged round the track. And there's that exquisite race engineering smell of burning diesel, oil and rubber, unique to ultra souped-up machines taken to their limits.

So it was at Brands Hatch in Kent on 18 April, when nine-times British Truck Racing Association champion Stuart Oliver secured a hat trick of victories, winning the grand final at this Truck Superprix event. After winning the shootout, Oliver started the final encounter of the weekend in pole position and led from lights to flag, confirming his position as the UK's leading truck racing talent. He also scooped victory in the first Class A race at the event, giving him a healthy lead in the overall championship standings.

But what's behind these mighty machines and, for that matter, their drivers? "My background is road transport through and through," reveals Oliver. "I'm a qualified mechanical engineer and I've been in trucking all my life. I run Martin Oliver Transport, the haulage business started by my father out of Hexham and Cannock in the West Midlands, but I've also been running my own truck race team – Team Oliver Racing – for 12 years now."

Trucks are his passion and he explains that, for him, the affiliation is firmly with MAN. "I race a MAN TGX 4x2 with the L day cab. It's basically standard but stripped right out and fitted with a heavy duty roll cage, which is fastened through the cab floor onto the chassis," says Oliver. Not that MAN is the only show in town: the Brands British Superprix fielded 22 tractors, including vehicles from Mercedes-Benz, Renault, DAF and the old ERF – and the European events have many more variants from other makes.

"Basically, the regulations governing truck racing are the same as those in Formula One, under the FIA [Federation Internationale de l'automobile]," explains Oliver. "Racing trucks have to be derived from series production trucks. So they must have standard chassis rails; the axles have to be in series production; and the silhouette of the racing truck has to match the road-going truck as closely as possible. But that's where the similarities stop."

He starts with the engine. "I race with a MAN six-cylinder D26 common-rail diesel – but heavily modified as part of the MAN research and development programme in Germany, which they use not only to improve race performance but also to prove engine refinements [for both efficiency and reliability] on production trucks." Heavily modified? "Well yes: my race engine has a standard MAN engine block, but with steel pistons instead of aluminium, to provide tighter tolerances and handle the higher compression ratio. It also has a different cam shaft, higher pressure and volume fuel injection system, and different inlet and exhaust manifold. Oh, and it's also got a bigger then standard turbocharger. All that takes it up from a standard 480hp engine to about 1,200hp. But the best part is the torque, which on my race engine is 5,000Nm, compared with 1,400—1,600Nm on a standard unit."

Now you begin to understand that thunder: this is no ordinary machine. What about that cam shaft? Oliver explains that the difference is to allow for more extreme variable engine valve timing and injection timing. "The ECU is highly modified and capable of injecting much more fuel for much longer periods," explains Oliver. "That's part of what gives us the scale of increased power. We also have a ceramic single-plate clutch running into a relatively standard 16-speed ZF manual transmission. It's a larger box, though, so that as the momentum of the drive goes up, the gearbox can cope. If anything is going to fail, it's the engine."

What about those axles? "We've got a fully locked 3.71 ratio rear axle, which gives us the 100mph at 2,600—2,700rpm. That's the maximum speed we can race to. We also have three-way, fully adjustable dampers on dual leaf springs front and rear, but they're also upgraded. The rear units, for example, are uprated leaf springs, with a torsion bar on top of the axle from a cross member, to stop the axle form twisting and to take some of the stress off the springs. There's also an adjustable antiroll bar system on the rear axle, which we set, according to the track history and live data from our on-board telemetry system."

That system monitors suspension movement, roll and pitch, but also the engine management system, braking, brake temperatures and steering geometry – all in real time, with the data presented to the team's track technicians in the pit.

And it doesn't stop there: "At Brands, we do 12 or 14 laps, depending on the race, but that means 15 minutes of racing. In that time we use about 60—70 litres of diesel and 220 litres of water. That's sprayed onto the vented brake discs, but also onto the engine intercooler. We need to keep the brakes cool at 300—500oC during harsh braking, so I can control that from the cab. But we also need to displace heat and reduce the air induction temperature to maximise oxygen intake at the engine's pressurised inlet. There's no EGR [exhaust gas recirculation] on these engines; just DPFs [diesel particulate filters] at certain circuits to avoid black smoke, depending mainly on the altitude."

So, in fact, his truck may look vaguely like a TGX with the L cab, but there's precious little that's standard about it – even the cab and chassis. In case you're wondering, Oliver explains that, because the cab is solid mounted to the chassis, the latter is fitted with a stiffening subframe. "Also, the engine is moved rearwards, because we're running on the minimum weight of 5,300kg and, to meet the regulations, 3,300kg of that has to be on the front axle. Also it's important to get the centre of gravity as low as possible. That's why we move the engine back about 80cm but also around 30cm down in the chassis."

We wish Stuart Oliver well in the remaining championship meets, which run to the end of October.


European truck racing season blasts off
Man tells us it has also been focusing on the European Truck Racing Championships, which, as we go to press, are about to blast off in Misano, Italy. 18 drivers from 10 countries and seven different truck brands promise to make the season an exciting one.

MAN teams Allgäuer, Birds, Cepsa, Hahn, Mariezcurrena and Robineau spent four days in mid-April at Nogaro, southern France, honing the performance of their race trucks, with MAN race engineers on hand to optimise suspension for the trucks, some of which have been newly constructed for the new rear axle FIA regulations.
Team Hahn Racing is one that has put together a completely new MAN TGX race truck during the off-season. Says driver Jochen Hahn: "The engine is noticeably more powerful than last year. You can see that in the lap times and the acceleration. The fully-locked rear axle, which is new because of changes to the regulations, is completely under control."

Author
Brian Tinham

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