The Evora 414E gets NVH treatment in anechoic chamber

The Evora 414E gets NVH treatment in anechoic chamber

As carmakers go, Lotus is something of an unusual company. As an OEM it's a small volume player, making sports cars that are still – as typified by the Elise, for example – the spiritual descendants of the stripped down 'light of weight' approach to design and engineering favoured by Lotus founder Colin Chapman. But Lotus is much more than a maker of Lotus sports cars. It does quite a bit of engineering consulting work – through its Lotus Engineering arm - for third parties, many of whom are big name OEMs. And Lotus has developed a considerable knowledge base and pool of engineering expertise through that work. Most importantly, the extensive working relationships and experience of working with volume makers means that Lotus understands how the bigger OEMs work and the kinds of systems and processes that they work to. It's a good exposure to have.

There is one drawback though. Lotus is not generally in a position to talk about the extensive work it has done for third parties (governed as it is by standard confidentiality agreements). The Lotus Evora 414E hybrid then, is something of a special case for Lotus. It's a concept car packed with cutting edge technologies that have been developed by Lotus for a Lotus car and therefore that it is in a position to shout about. It's a working concept that shows off Lotus engineering expertise. And Lotus has naturally been keen to get journalists behind the wheel to help spread the word.

The background to the project that spawned the 414E (as well as the Infiniti Emerg-E concept; basically the same car as the 414E, but with a different body) is certainly interesting. The UK government's Technology Strategy Board put up 50% of the overall GBP19m project funding with the aim of helping to develop the UK's EV technologies supply base by working with three OEMs – Lotus, Nissan (Infiniti) and Jaguar Land Rover. From the supplier industry, Evo Electric, Axeon and Xtrac were among those involved. So, the TSB wanted to kick-start a project that would get suppliers involved in EV technologies – which it sees as a big part of the automotive future and a strategic priority for the UK automotive manufacturing sector. And Lotus wanted a research project to demonstrate its hybrid technologies and capabilities. It was a good fit.

However, while Lotus and Nissan went down the series hybrid range extender plug-in electric vehicle route, JLR went off in the direction of a parallel plug-in hybrid (the Jaguar XJ-e, also a working concept).

The experience in developing the 414E was certainly a learning exercise all round. “We found ourselves getting much more involved with the suppliers on this project than would normally be the case,” says Steve Doyle, Lotus Chief Engineer Hybrid and Electric Vehicle Integration. “The nature of the technologies, and some of the start-ups we were working with, meant that we were in a very good position to advise them for the good of the project. We could find ourselves, for example, advising them on the products and inputs from their suppliers because of our better knowledge in some areas,” he says.

In terms of the engineering objectives for Lotus, the integration of a high power motor/inverter drive, a high energy battery pack and the inclusion of the Lotus range extender engine stand out. There was also quite a bit of work to do on control systems integration, safety systems and analysing torque vectoring for the independently driven rear wheels.

The result is a car that is not quite the finished article, but a car that shows just how close Lotus can get to making something packed with genuine technological innovation. A sports hybrid with a range extender is a pretty complicated engineering proposition. Lotus has successfully integrated a series hybrid driveline into the existing Evora, the vehicle controlled by a Lotus developed control system. And it has also, in the process, managed an embryonic supply chain. You will not be able to buy the 414E, it's a one-off concept, but it is a car that works very well and did not feel at all like a raw or rough at the edges prototype to drive. The interior was Evora, but with a few modifications – such as a dynamic display panel showing power output from battery and range extender.

The Evora 414E is powered by a pair of 201bhp electric motors ('synchronous axial flux drive motors' to be precise), and the lithium-iron phosphate battery pack can be charged from either a plug socket or by the 1.2-litre range extender engine specifically developed for range extender applications by Lotus. The car is targeted to travel thirty miles on a full battery charge and has a range of 300 miles on a combination of battery and petrol.

Performance is not significantly different to the standard Evora. It will do 0-60mph in 4.4 seconds and has a top speed of 133mph. Average CO2 emissions are estimated at 55g/km. I can vouch for its speed around the track at Hethel; it's very quick and nimble. Weight distribution also seemed fine, despite the fact that the 414E has gained 377kg (to 1,759kg) over the petrol Evora. Lotus has worked on the weight distribution to make it very similar to that on the standard car. But there's no getting around it: a hybrid like the Evora has got a lot of equipment packed in, not least the battery (which takes up a fair bit of room where the rear 'plus two' seats would otherwise be). Light it ain't, but it is very quick and efficient. The additional power from the range extender engine gets you Lotus performance in a car with an estimated CO2 rating of just 55g/km. The range extender in the 414E kicks in seamlessly when you stick your foot down for some serious acceleration. Well, not quite seamlessly, it is quite loud, but it hasn't had the full NVH treatment.

Actually, aural feedback raises an interesting issue for performance electric cars like the 414E. The buyer of a Lotus sports car – having been bred on the internal combustion engine and being something of an enthusiast - may well want a rather more aurally sensorial experience than an electric car naturally delivers. Lotus has thought of that. It is working on introducing sound ('HALOsonic sound synthesis') which includes external sound synthesis for pedestrian safety and an internal sound synthesis providing the driver with active feedback. A virtual gear shift with a simulated 7-speed paddle shift linked to the HALOsonic Sound Synthesis is also in the works. That will involve a power interrupt/regenerative breaking function to simulate gear change. It is simulation though, conceived wholly because we are hardwired for ICE sounds and feedback and we will take some weaning off it. In twenty years' time it may be something we smile about.

One interesting development detail was in some of the software that Lotus developed for use in the 414E project. Now, if you are developing one car, a high-tech one like the 414E, it's an expensive asset. You want to look after it, avoid prangs where possible. Real world testing brings risks, is time consuming and comes with considerable cost. Safety systems were one of the development priorities for the 414E. Lotus built a virtual car using 'carmaker' software for safety case scenarios that meant it could take the car around the Hethel circuit virtually and conduct thousands of scenarios without actually having to do them (if you see what I mean). There's a big cost saving as a result and that software investment is in place for future models. It provides one example of the long-term spin-off benefits that a project like this can help bring about.

Over the next year Lotus is planning to refine the car further. There's more learning ahead and the 414E looks like a commendable project, both for Lotus, and for the UK government's efforts to stimulate a nascent UK supply chain in electric vehicle technologies. On that latter point, I sense that there is a long way to go. Automotive supplier industry might perhaps lies elsewhere these days, but at least projects like this show some capabilities and what can be achieved through smart collaborative efforts and approach. At a strategic level for the UK auto industry, learning what is difficult, or what can't be done here, can be as valuable as realising some strengths and possible competitive advantages for the future.

Moreover, Lotus Engineering can rightfully point to its successful leadership role in the development of the 414E/Infiniti Emerg-E projects. You won't be able to buy the 414E, but that's not the point. It's an impressive working model that shows what Lotus Engineering is still capable of and why Lotus remains a relevant brand in 2012.