Efficiency = Performance

This year’s F1 championship has been dominated by Mercedes AMG Petronas. The Silver Arrows have superior performance to their competitors, and mixed with the driving skills of Rosberg and Hamilton, the trophy cabinet at Brackley may soon need an extension. To find out more about the latest technology in Formula 1, and how it compares to what we’re seeing in road cars, I was treated to a unique look into the research and development at Mercedes F1.

The visit to Brackley started with Paddy Lowe, executive director (technical), setting the theme of the day: ‘Efficiency = Performance’. The 2014 F1 regulations brought significant changes in the way the cars can operate, with fuel efficiency being one of the biggest. In previous years there were no fuel limits, and in 2013 Mercedes used approximately 155kg of fuel per race with the V8 engine. This year the limit is 100kg of fuel, and Mercedes sticks to this limit with similar power outputs to the cars of last year. This is achieved through advances in efficiency within the High Performance Powertrains (HPP) team in areas such as tribology, boosting, hybrid powertrains and aerodynamics.

TRIBOLOGY_

Tribology is the science of friction in mechanical engineering, and Mercedes’ F1 team has a specific research group to help reduce friction in the engine. Dr Paul Crofts, head of materials engineering at HPP, told us how his work with cylinder bore linings reduced the friction in the new V6 to 15 per cent from the 18 per cent figure experienced in the V8. This may not sound like a big deal, but less friction from the engine components means more of the energy in the fuel can be used to produce torque, which means better lap times. It’s achieved using Mercedes’ patented ‘Nanoslide’ technology, which was first developed for road cars. The heavy, iron cylinder-bore liners of a conventional engine block (pictured) can be removed and coated in a lightweight metal that reduces piston-to-bore friction. The technology is directly shared between the F1 and road car teams; the road car blocks and F1 blocks are even coated on the same production line.

BOOSTING_

To increase the power outputs of the lower-capacity V6s of 2014, Mercedes AMG adopted a large turbo to increase air flow into the engine. There’s a clear parallel with road cars here, of course, where downsized engines with a turbocharger (or two) have become increasingly common. Indeed, Mercedes recently announced that its SLS replacement, the AMG GT, will have a smaller engine – down from 6.2 litres to 4.0 (albeit still a V8) – with twin turbos, rather than being naturally aspirated.

HYBRID POWERTRAINS_

Also helping make the power output of this year’s F1 cars similar to the units of 2013 is the hybrid system. The synergy between F1 and road car technology here is obvious when considering the forthcoming S500 Plug-In Hybrid. Last year’s F1 cars ran V8s, as does the existing S500. The new F1 engine loses two pistons, is turbocharged and features a substantial hybrid element – just like the hybrid S500.

The S500 hybrid outputs 436bhp and 479lb ft of torque – figures close to the old S500, but with a 3-litre V6 as the car’s largest source of power.

Uwe Keller, technical project manager for hybrid powertrains, explained that the next step for hybrid powertrains in Mercedes road cars is to develop wireless charging. Testing of the ‘unplugged’ technology is imminent, with 90 per cent efficiency promised.

AERODYNAMICS_

Although aero is massively important for both F1 and road cars, it is important for opposing reasons. F1 cars need downforce to increase grip, whereas road cars need a low co-efficient of drag (Cd) to increase efficiency. Mercedes F1 is limited in scale and hours of operation for its wind-tunnel testing. However, a full-scale wind tunnel with a road belt is available at all times for the road team. Wind tunnel runs and computational fluid dynamics are invaluable to achieving superior performance, and the Mercedes CLA’s award for the world’s lowest Cd on a production car is testament to the work that the engineers do.

VERDICT_

So, the drive for efficiency in cars is no longer restricted to production models. Mercedes AMG Petronas has shown that hybrid technology is no longer just for the anorak devoid of a passion for speed. The W05 chassis has demonstrated that battery hybrids can be staggeringly fast on track, and Mercedes’ latest forays into road-car hybrid (S500 Plug-In Hybrid) and fully electric (SLS Electric Drive) drivetrains will allow the public to sample similar tech with a performance bias.

Hopefully the technology exchange will continue – and who knows where it will lead next? We may start to see energy harvesting from turbo units, and even suspension travel, in the not too distant future.