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Breaking the rules

From the September print issue
William Kimberley

When it was shown to the public for the first time at an exhibition at Monaco in April, the British designed Caparo T1 two-seater caused quite a stir.

While it was an odd looking car, the fact that the people behind it included Ben Scott-Geddes and Graham Halstead, both ex-McLaren Cars engineers and part of the team that developed the McLaren F1, gave it great credibility.

A bit different: the Caparo T1 made waves at Monte Carlo

Featuring its own supercharged 2.4 litre V8 engine delivering 480 bhp at 10,500 rpm giving it the performance of a Le Mans sports racing car but with a range of 400-500 miles from its 70 litre fuel tank, it was not just about performance, but about weight.

Lighter than a Caterham at 465 kg – the complete powertrain including the transmission weighs just 130 kg – it was the first car in the world to exceed the 1,000 bhp-per-tonne, twice the power-to-weight ratio of a Bugatti Veyron and a significant breakthrough in terms of pure automotive engineering.

At the time of its creation, Scott-Geddes and Halstead were working for Freestream, their own engineering consultancy, but then received an offer they could not refuse from Caparo, an Anglo-Indian engineering company that has designs on the automotive world as a tier-one supplier.

One of the ways of achieving this, it believes, is to have an advanced automotive technology and engineering design company in its portfolio. So in March this year Freestream became the basis for the newly created Caparo Vehicle Technologies (CVT), the focus of which is to provide technology development, materials engineering and design services to the mainstream automotive, motorsport and aerospace markets.

Not just content with having two ex-McLaren employees as directors with Scott-Geddes becoming design director of the new company and Halstead the engineering director, Angad Paul, Caparo group chief executive, then recruited Mark Findlay, ex-Ricardo head of computer-aided engineering, as managing director.

His first task was to recruit a team of around 30 engineers with the skills necessary for handling sophisticated engineering design contracts from carmakers and tier-one suppliers. Within a few weeks had managed to entice Gordon Murray, former chief designer at the Brabham Formula One team in the 1970s and then technical director at McLaren Cars and the man responsible for the McLaren F1, to join the fledgling company as director of advanced concepts.

In one blow, Paul had created a specialist company that boasted engineers who in addition to their skills in vehicle design and engineering had particular expertise in materials technology, having been responsible for the Mercedes SLR McLaren sportscar. This was the first advanced composite all carbon body structure to undergo Euro NCAP testing during its development.

This capability and understanding of materials performance, including how materials as dissimilar as aluminium, advanced composites, engineering plastics and high-strength steel can be joined – and which is the best material for a particular part of the car – is important to manufacturers needing to reduce the weight of vehicles to make them more fuel efficient without compromising active and passive safety. And it is this theme that is dear to Murray.

“There is a great deal of talk nowadays about saving weight and yet every single car I see that comes out that is a new version of a previous model seems to be wider, slightly longer and a bit heavier,” says Murray. “Their argument is that ‘if we hadn’t applied some weight saving, it would have been even heavier’, but that’s not really an argument for me.

The Caparo: Twice the power-to-weight ratio of the Veyron

“OEMs believe that they are doing this sort of thing in-house because they have departments concentrating on these issues. However, all the signs to me personally are that they recognise that they are not actually getting the job done and that’s because big corporations, and I have worked inside five or six of them, do not really ever let go. They may set up a separate studio and give it autonomy but in reality it still has to operate within the rules.

“I think that certain companies, and there are some that are much more forward thinking than others, will realise that they will have to go to smaller, more flexible, lateral thinking outside groups.” And this is where CVT comes in.
Bearing in mind what Murray has just said, does he really believe that a small specialist company like the one he is now involved in really has a chance with the OEMs?

“The last two years at McLaren when Ben and Graham were my two senior engineers we had what were called advance concepts which was just studying bringing composites to the high-volume market. However, it wasn’t just the pieces, it was the whole process and all the problems surrounding structural stability, high and low temperatures and the associated problems with the manufacturing and tooling processes, quality control and non-structural testing and all those issues.

“So we can be different because we are an extremely experienced small band of people that can react quickly and think on the hoof and will think laterally and outside the box a bit and make it happen. Not just a part, but a production solution for whatever volume the customer wants, to a point.

“So we like to offer more than having a plastic part on the car and would like to offer the manufacturing solution. The principle is that we would supply the manufacturing process and do all the necessary crash test work, elevated temperature work and tooling projections.”

Murray is rather dismissive of car companies that claim to be using advanced composites on their vehicles, saying “until now car companies tend to pay lip service as it’s usually applied to a non or semi-structural part like a carbon fibre boot lid or a thermoplastic front wing. It all helps, of course, but actually it’s a bit like the hybrid – ‘aren’t we good because we’ve got a plastic part on our car?’”

For all his pioneering work on carbon fibre in Formula One – in 1978 he was the first to introduce it on a Grand Prix car on the Brabham and also the first to introduce carbon brakes following the lead from Concorde – Murray is a great fan of thermoplastics.

“I think that thermoplastics have a huge future in car parts. It’s a small, easy and cheap plant to set up and far more cost-effective than welding and assembly plant or a pressing plant – and that’s another advantage of composites – you don’t have to make 45 parts, you can make two. We actually got to the point, without giving too much away, where our little team thought we could produce a chassis for a low volume sports car, for example, in one part.”

Murray recognises, though, that thermoplastics are generally not good enough for car parts because they are not stiff enough and fail what he calls “the touch test” where even if it is stiff enough for its application, such as a wing, if it clonks when someone leans against it, then it fails. Composite thermoplastics get rid of all that.

However, advanced composites are limited by the manufacturing processes. “Current advanced composites have an absolute volume of limitation,” says Murray. “Even with the technology we are looking at with the pre-preg carbon, even if we bottom out that production and quality control technologies, you are still talking only 5,000 to 10,000 units a year. Once you go to thermoplastics, though, the cycle time comes way down and because the manufacturing process is fast and simple, and you can have parallel lines.”

To differentiate between materials, Murray classifies advanced composites generally as thermosets “which means that you are using something like epoxy resin. It doesn’t have to be carbon, it can be glass, Kevlar or any man-made fibre. Once it’s been put in the oven under pressure or in a vacuum, it’s cured. Thermosets with most resins have a minimum cycle time and while it’s coming down all the time, it will always be slower than thermoplastics.

“I think we can get structural the way we at CVT are making them. I can’t give that away yet, but I do see structural thermosets coming into vehicles or products up to about 10,000 units a year, although this is impossible at the moment.
“Once you go from thermosets to thermoplastics then the process time comes way down. However, the problem has always been introducing the reinforcement but we have some ideas along those lines.”

These lightweight materials can have a great part to play in Murray’s scheme of things but he acknowledges that car companies still have doubts about using them widely. “We want to go a bit further because it doesn’t have to be a non-structural part – we are talking about semi-structural and fully structural parts which could include the crash structures, seat frames or any number of parts, depending on the volume that’s required at the end of the day.”

However, Murray knows the limitations on what CVT can offer OEMs. “It’s one problem going to an OEM and getting them to think light, small or safer, but trying to get them to accept your geometry or platform is very difficult. I wouldn’t even try and do that because they have their own ideas and their own departments and they are so fussy about platform shape and its end use.

“However, trying to sell them a new technology to something that they can see as an existing part, for example, an anti-side intrusion beam is easier. For example, we had a really sophisticated solution at McLaren using a mixture of composites and aluminium, which was half the weight and three times the strength of steel. Something like that, which car companies can see is not changing their geometry, you can sell them, particularly if it’s the same price or not much more expensive.”

One material that is very expensive is carbon fibre, but Murray is optimistic about its use in future vehicles. “The general trend for the cost of carbon material is going down but it will never be cheap enough to appear on the volume production car in any great quantity. However, I believe it will do so as a localised reinforcement.

“What we were looking at McLaren and continue to do so at CVT is moving carbon out of the hand layout pre-preg racing car and jet fighter business into maybe medium volume. We have some ways of doing that we think, and for the higher volume you’ve got to look at pressed parts and thermoplastic parts on which we have also done a great deal of work. What we need to do now is to have a two-way conversation with manufacturers.”

Caparo is enthusiastic about Murray’s ideas. “This is an exciting and logical development for Caparo,” says Paul. “I warmly welcome this opportunity for the group to move up the value chain with this high added value proposition. We will use our vehicle technology company to add new materials know-how to our existing aluminium and steel structural capabilities.

“To me, advanced composites represents an important development in delivering to our customers better vehicle efficiency with less environmental impact and without having to compromise the enjoyment of motoring.”