Interview with the designers


Usually Serious. If it wasn't the cars themselves, then the fortunes of the company have certainly been deserving of this acronym. Lotus seems to have staggered from one crisis to another: blithe market failure of the Elan, being bought and then sold again by General Motors and then being snapped up by the Italian company Bugatti.

Yet despite the Norfolk-based company's rollercoaster ride, its reputation still burns as brightly as even Nothing, it seems, can dull the motoring world's enthusiasm for the famous green and yellow rounded

Lotus has always been a technology-led company. Over the years it has given tastes of such futuristic paraphernalia as active suspension systems and in-car noise-canceling. However, in terms of car manufacturing it has always relied on the relatively simple: composite bodywork, outrageous handling and even more outrageous amounts of horsepower extracted from small, four-pot engines.

But when it tried to present a modern, high-tech face in the guise of the 1989 Elan, it all went horribly wrong. The Elan, Lotus's first front-drive car, was powered by a Japanese engine and was radically styled. Although it was received well, it was doomed to fail: its development costs had spiraled out of control and it was both difficult and expensive to make.

The launch of the Elise roadster at the Frankfurt Show in September failed to provoke quite the same flag-waving as its Elan predecessor had done. Yes, it arrived amid a tidal wave of new roadsters, but even so one would have expected a little more excitement. After all, the Elise seems perfectly suited to Lotus's heritage: small, light, fast, advanced, race-tuneable and classically styled.

Indeed, once you've been talked through the elegant aluminium chassis by Richard Rackham, senior design engineer and father of the project, any doubts about the wider significance of the Elise are dispelled.

Lotus has a world production first in the bonded and extruded chassis, and is likely to use it again in future lotus cars, including an eventual replacement for the Esprit. The idea is simple. The chassis is constructed from around 25 different aluminum extrusions which are bonded and riveted together to give a light, cheap-to-make, super-stiff construction that's easy to adapt to other uses.

Aluminum extrusions are best described as hollow beams, some square, some rectangular, some triangular. They are formed by squeezing liquid metal through a die, rather like squeezing icing through a shaped nozzle, and are usually used to construct the frames of double-glazed windows.

The great thing about using extrusions is that it costs just a few thousand pounds to make a die, so the whole chassis can he tooled up for a fraction of the cost of just one conventional metal pressing. It also allowed Lotus's engineers to design each beam so that it's the perfect shape for the loads it needs to carry. The various beams are then 'harmonised' using computer technology into one unit that is uniformly stiff all oven This would be almost impossible with conventional materials.

Lotuses method of construction is also uncommon There isn't a single weld in the aluminium structure: all the beams are glued and riveted into place. The adhesive is cured at 200deg C. 'We have to anodize La smooth, microscopically thin, diamond hard finish each beam before assembly,' says Rackham. 'This not only gives corrosion protection, but also gives the aluminium a surface suitable for glueing.' The rivets are not strictly necessary structurally but, according to Rackham, they prevent the joint 'peeling' apart In a heavy smash.

Safety, as you would expect, is heavily featured. The two main side beams are huge and, comhined with the aluminium door beam, give excellent side-impact protection for a car of this type. Front and rear 'sacrificial chambers' have been built into the structure to make the Elise cheaper to repair after a crash.

The front member is made of composite material and includes the radiator, which is bonded in and lies horizontally in the nose. At the rear it's the sub-frame that is sacrificed in a crash; it's the only part that is made from sheet steel. The 40-liter fuel tank is hidden in the main cross-member (torque tube) behind the seats and in front of the engine.

Although the chassis is made in the same Danish factory as the Renault Sport Spider, Lotus claims its method of construction is superior. The Renault is a welded chassis which, says Rackham, is not the best way to treat aluminium. 'Welding distorts the material and reduces strength at the joint. Because our chassis is bonded it can be made with incredible accuracy. The hard points (suspension mountings and so on) arc accurate to 0.5mm - unheard of in a conventional can'

Rackham also says that the accuracy of construction and stiffness of the chassis has allowed 'a very pure suspension set-up'. The Elise has double wishbones at each end and to save money the system uses the same wishbone bush and outer hall joint for all four converse The suspension is tuneable like a racing car's and is designed to be dropped by 50mm with different dampers.

There's also an optional NACA ducted undertray which acts as a diffuser and adds downforce. The chassis is symmetrical, so it can be built for either left- or right-hand drive.

Just like Elise stylist Julian Thompson, Rackham was inspired by Ducati motorbike design, because 'everything is functional and stylish'. Importantly, Rackham reveals that the Elise chassis 'is scaleable' - using the same tooling, it can be lengthened or widened for minimum expenditure. This makes a next-generation Esprit both less costly and more likely.

The styling of such a car might be taxing Julian Thompson's mind as you read this. After all, the shape of the Elise has caused some controversy for being, well, not controversial enough. Thompson seems genuinely puzzled by the criticism; after all, his design team fought off big-name proposals from Zagato, IDEA and Elan stylist Peter Stevens. The design brief came direct from Bugatti vice-president Giampaolo Benedini, a successful racer and a Lotus 23 owner. According to Thompson, it was pretty straightforward: 'Everyone should know that it's a Lotus: light, simple, elegant, dramatic. We've steered away from that in the past and caught a commercial cold. Firms like Ducati and Harley Davidson that have succeeded in a niche have done so because they've understood their customers. Why do people buy a particular product? It's because of history which is what sets us apart from Toyota, Mazda and the rest.

'The Elise is not deliberately retro, but has some of those elements. After all, nobody criticised the VW Concept One or Chrysler Atlantic. Using retro elements is very much a contemporary move, and the Elise's styling has plenty of modern touches, too. 'We can't understand why the press are so enthusiastic about cars like the Fiat Coupe, Barchetta and Alfa GTV. To us, they're not beautiful. I think we've made the right decision with the Elise: it's beautiful in the way old cars are beautiful.' Thompson's greatest problem was to minimize the number of bought-in components to avoid a kit-car look. For the record, well known bits include Cavalier column stalks, Peugeot 306 switches, Rover interior doorpulls and Alfa 33 circular face vents - the latter also to be seen in the Ferrari F50. Plus, of course, Lotus used the Rover engine and transmission from the MGF, although there's an 'Elise' cam-cover.

One detail it was important not to buy in was lamps. So Lotus tooled up a single round lamp unit in two colours - red and amber - with a clever mounting system, for use in six different places: indicators front and rear and rear stop lights. Up front, the headlamps are stock circular units with convex lenses mounted under plastic cowls. 'To make the car more jewellike,' says Thompson, 'we've created our own steering wheel, pedals [stunningly extruded from aluminium], seats, gearknob and wheels.' Viewing the Elise in the open air, I would suggest that Thompson's own Ferrari Dino GT has influenced the Elise as much as his Ducati.

Like the Dino, the Elise has pronounced front wings, cowled headlights, a large body-side air scoop and huge Ford GT40-style ducts in the bonnet. At the back, the (aluminium) engine cover is a riot of grilles and bulges. The pert rear end has a duck-tail spoiler in order to reduce lift. In truth, this and the chin aerofoils have slightly compromised the purity of Thompson's design, but even so, the Elise looks far prettier in real life than it does under show spotlights.

Because the body panels are non-structural, effecting styling changes would be both easy and cheap. It's also clear that Thompson would countenance adaptations of the Elise: the designers have plenty on the drawing board already.

The cockpit has a real sense of drama. Once you've clambered in over the huge side member and settled into the Ferrari-esque seats, you feel a genuine sense of excitement. It's that huge space in the footwell, the straightarmed driving position, the expansive view over the curvaceous nose and the starkness of the aluminium dash extrusion. Of course, the sills and floor shine brightly in silver anodised aluminum, resulting in an interior that is truly unique.

There was a lot of debate about weather protection. In the end the car got wind-up windows, a clip-in rear window and a clip-on roof. This system makes use of the huge steel rollbar, which also houses mounts for RAC-approved roll-cages and five-point harnesses (the company is looking at a onemake race series). Rackham says that he packaged the most powerful heater he could, and it is really powerful.

Power hikes are likely from the 125bhp that will initially be on offer Rackham reveals that the radiator is capable of handling a 200bhp engine: what price a 1.8litre K-series turbo?

The Elise is clearly the product of a small and dedicated team. Rackham's chassis department consisted of just four people, the design team was little bigger, and the integration of the two was helped by the fact that Rackham and Thompson are close friends - in fact, Rackham was best man at Thompson's recent wedding.

The rigorous simplicity that has characterized the Elise project might finally be the saviour of Lotus as the maker of high performance sports cars. Perhaps from now on, Lotus can stand for Lots Of Technology Unique Styling.

Car Magazine, January 1996