F1 car

Racing greens

A race car built with vegetables and powered by cocoa butter may be green, but does it go? E&T investigates.

If you thought motorsport was all about raw speed and race day excitement, think again. Competitive auto-racing is going green.

Last year, the World Motor Sport Council vetoed development into fossil fuel-guzzling Formula One engines, instead encouraging the industry to focus on alternatives such as hybrid fuel systems. At the same time, Formula One is pushing hybrid-drive systems that recover braking energy in race cars, while governing body the FIA has a 'Make Cars Green' website, aiming to reduce the impact of cars on the environment.

But while the lion's share of race car development has focused on cutting carbon emissions, a team of researchers from Warwick University and the Warwick Innovative Manufacturing Research Centre in the UK wants to do more. Their proof-of-concept Formula 3 race car - 'WorldFirst' - not only runs on a biodiesel blend of waste cocoa butter and vegetable oil, but has been built with a host of unconventional sustainable materials, including flax, carrot fibre and potato starch.

Unveiled in early May 2009, the car raised a media frenzy inspiring headlines such as 'Race car gets chocolate power' and 'It's not just speedy, it's delicious'. But given its green and somewhat incredible credentials, should we take the race car seriously? Yes, says Warwick University researcher, Dr Steve Maggs, as the vehicle currently meets all the Formula Three racing standards, bar its biodiesel engine which F3 cars cannot currently use. It boasts a top speed of 120mph (193km/h) and 145mph (233km/h) is promised.

What's more, the team is itching to put it through its paces. Researcher and project manager James Meredith will run the vehicle at this year's Motorsport Industry Association media day in June. The team has also been invited to showcase the car at the Goodwood Festival of Speed in July, and they are considering a demonstration at the European Grand Prix in Valencia.

As Meredith says: "It feels pretty amazing, actually. It's very quick and feels like a very aggressive, serious racing car. It's pretty fun and I'm looking forward to getting it on the racetrack."

So how did work on the world's first sustainable and renewable materials-based racing car get off the ground? Maggs and his colleagues first looked at the standard F3 car, worked out which parts could be replaced by sustainable versions, and then started approaching industry players.

Sustainable potential

"We asked a lot of people, 'are you interested in getting involved?'," explains Maggs. "Some people saw the potential in it and some just told us to bugger off."

Thankfully, a host of industry heavyweights didn't. Formula racing tyre supplier Avon provided polycyclic aromatic-free tyres. Polycyclic aromatic hydrocarbons - some carcinogenic - tend to accumulate in aquatic environments and the subsequent food chain.

German chemical producer BASF provided the team with its 'ozone eating' coating for use on the car's radiator. Already present in most Volvo cars and some BMW, Mercedes and Hyundai models, so-called PremAir contains a catalyst that converts ozone molecules - harmful at ground level - to oxygen molecules on contact.

At the same time, Japan-based wiring harness manufacturer Yazaki supplied a halogen-free wiring loom for the car also designed for easy disassembly and recycling. And UK oil pump supplier Pace Products developed a race-specification lubrication system to accommodate the plant-based lubricants provided by UK-based Fuchs Lubricants.

Crucially, world-renowned race car manufacturer and defence engineering company Lola Group decided to take part. The team approached the business with their idea in March 2008 and, as it happened, an F3 car was collecting dust in the Lola Cars workshop.

"A car that we'd built for the 2005 British F3 season raced to two wins by Danilo Dirani at Donington Park," says Sam Smith, communications manager for Lola Cars. "We decided to provide Warwick with the actual monocoque chassis of this car."

Monocoque f3 car

The so-called monocoque or single-shell design refers to a chassis that relies on a stressed skin rather than an underlying frame for strength. Widely used in racing cars, it is typically made from carbon fibre reinforced composite, a material consisting of thin carbon fibres embedded in a plastic resin.

While the composite yields a lightweight, strong and stiff chassis that optimises handling and provides a safe survival cell for the driver, it's green credentials are poor (see 'What's wrong with carbon fibre?' p27). Unfortunately, the greener alternative, recycled carbon fibre composite, is not as strong and cannot be used in safety-critical applications.

Undeterred, however, Maggs' team and Lola joined forces with global business Recycled Carbon Fibre to demonstrate exactly what the material can do. Formerly known as Milled Carbon UK, the company has developed a system that recycles waste carbon fibre composites using pyrolysis, a method of incineration that chemically decomposes the materials by heating them in a near oxygen-free atmosphere. The recovered fibres are then sold back into industry at a much reduced cost relative to virgin fibres and with only a 10 per cent reduction in physical and mechanical properties.

"In the case of WorldFirst, Milled Carbon took existing composite and removed the out-of-date resin in its pyrolysis process," explains Maggs. "This recycled material was then re-impregnated with resin at Lola to form semi-structural components."

The semi-structural material was then used across the car's bodywork, namely the engine cover and damper hatch, which covers the vehicle's dampers on top of the chassis. "As Warwick has showcased, the material is ideal for components such as the wings, the car's trim, and lightweight structures such as the damper hatch," adds Smith. "In years to come, industries that use a lot of composites, including motorsports, are going to have to take a closer look at recycled carbon fibre."

But it's not just the latter that industries will need to look at. As the European Union tightens its waste and end-of-life disposal policies, the European Automotive Industry has been looking to use more natural fibre composites. With this in mind, the Warwick researchers used a range of these materials when building their race car.

For example, the bib is made from a woven flax fibre, impregnated with epoxy resin. Here, the Warwick team and Lola worked with France-based Lineo, a manufacturer of high-performance flax composites. The team also built a side pod made from a glass fibre composite with a closing panel based on flax fibre composite. In each case, the composites' epoxy resin was derived from recycled plastic bottles, supplied by resin manufacturer Cray Valley.

Meanwhile, the team collaborated with US supplier of automotive seat systems, Lear, to produce a seat comprising a flax composite shell filled with soybean oil-based flexible foam. The Warwick team claims that SoyFoam is an industry first and is more environmentally-friendly than traditional petroleum-based foam.

3d woven composites

But perhaps most excitingly, the car showcases a new 3D woven natural fibre composite by way of its barge board. Pioneered by Dr Julie Soden from the School of Art and Design at Ulster University, Northern Ireland, the composite comprises a multiple stack of flax fibres with so-called 'through-the-thickness' threads running perpendicular to, and linking, the flax. This 3D woven structure is embedded in an epoxy resin, some 5mm thick, to form the barge board.

"In a normal 2D composite you have a fabric layer, followed by a resin layer, followed by a fabric layer and so on. Under stress these will typically fail or delaminate in the resin layer," explains Soden. "However, our through-the-thickness threads are viscose rayon yarn - as used in car tyres - and act as crack stoppers, preventing delamination."

Soden says the material is woven all in one on a fully-automated, customised electronic jacquard power loom typically used for heavy-duty industrial textiles. Soden also intends to use biodegradable, rather than epoxy resins, if more barge boards are required.

Beyond barge boards, Soden believes her 3D woven composites have an exciting future. "We've been approached by a US consortium to investigate flax reinforced composite roof panels," she adds. "We don't need more parcel shelves and things like that, these materials will have excellent opportunities in more high performance automotive applications, structural load-bearing and safety critical parts."

Eat your greens

Materials based on vegetables also featured heavily in the car. The steering wheel, believe it or not, is made from a novel material called Curran, derived from carrot fibres.

Developed by Scotland-based Cellucomp, Curran is made by, first, extracting cellulosic nano-fibres from carrot pulp, left over from carrot juice manufacture. The fibres are then mixed with resins to give a high strength material that can be moulded into tough, durable components. Reports suggest that up to 80 per cent of Curran's fibre content is from carrots, and business partners Dr David Hepworth and Dr Eric Whale believe their material will rival glass fibre- and carbon fibre-reinforced composites in non-safety critical applications.

To create the steering wheel for WorldFirst, Maggs and his team worked with Cellucomp to produce steering wheel moulds. Curran paste was then injected into the mould to form the part.

Maggs explains: "We did a little modelling, created the rapid prototypes and tooling, before producing our race specification steering wheel. Cellucomp usually makes fishing rods, which are thin-walled tubes, but this is the first time they've done a bulk component. We've actually got a solid lump of Curran."

And the vehicle's vegetable fetish doesn't stop there. To make sustainable wing mirrors, the Warwick team joined forces with BioPolymer Network, New Zealand, a consortium of bio-polymer and bio-composite manufacturers.

The business had for some time been working with New Zealand-based PotatoPak Ltd, a manufacturer of potato starch food plates, bowls and punnets (see 'Potato packaging', top of page). BioPolymer Network was certain their rigid, strong material, also called PotatoPak, could be used in WorldFirst's wing mirrors. The Warwick researchers agreed, and set to work designing a prototype based on a potato starch core and flax fibre shell. Biopolymer Network then made the prototype wing mirrors using PotatoPak and flax.

"I don't think anyone's made wing mirrors out of this stuff before," laughs Maggs. "The very first batch did look a little like McDonald's containers, but we are going back to get some better ones done."

A 'chocolate-fuelled' race car was always going to hit the headlines, but Maggs asserts WorldFirst is set to showcase yet more breath-taking environ-mentally-friendly developments. While the car currently uses non-carbon cast-iron brake discs, as supplied by AP racing, UK, brake pads derived from cashew nut shells are under development.

And although the car is equipped with a six-speed sequential gearbox, supplied by Hewland Engineering, UK, future work will involve integrating a hybrid system to recover braking energy.

The Warwick team is also busy working with Scott Racing, the UK engineering business that supplied the calibration for the WorldFirst 2-litre BMW diesel engine, enabling it to run on biodiesel derived from waste choclolate and vegetable oil.

"Together we're mapping the engine for different blends of biodiesel, but the eventual aim is to understand more about the variability of feedstocks," says Maggs. "A lot of work has been done on standardising biodiesel blends, but we are looking to see if we could produce an engine that could cope with a variable feedstock."

If you thought the chocolate-based fuel would be a hard act to follow, you could be in for a surprise. As Maggs says: "We would really like to take the waste fat from the University canteen, chuck it in, and race the car."

Further information:

F3 green race car - check out the video! [new window] (Automotive and Road Transport Systems Network)

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