It wasn’t midnight, and it wasn’t even quite midday, but Lotus decided the time was right to turn its new V6, naturally aspirated, mid-engined coupe from a (Project) Eagle into an Evora. The transformation came at the British International Motor Show in London and was necessary because the Eagle name was registered to another company. Evora is partly an amalgam of "vogue" and "aura" but with an initial "E" to continue Lotus product identity.
Although the new car, a 2+2 powered by a modified Toyota VVT-i 3.5-L engine, takes some styling cues from other Lotus models, it is highly distinctive and has a totally individual identity. Limited details of Project Eagle were released just prior to the Show, but now Technical Director Simon Wood is able to discuss the project in detail.
"It is a totally new car," he said at its unveiling. "It uses similar chassis technology to that incorporated in the Elise and Exige and also our VVA (versatile vehicle architecture), which has been applied to the APX crossover concept. But for Evora, these technologies are in a different form to meet the levels of investment necessary for the low-volume (about 2000 units a year) Evora compared to the higher volumes of the other cars from the original VVA. So we have combined our adhesive knowledge used for the Elise with the VVA nodal structure to low-volume VVA, using both bonding and riveting."
Instead of corner nodes in the structure, the Evora, weighing in at 1350 kg (2975 lb) in prototype form, has a set of foldings and extrusions to handle crash impulses. The car has parallel extruded sections, along and across the structure, to facilitate and make cost-effective changes to the car’s dimensions. A welded steel subframe is used at the rear.
The car is expected to appear in two-seat and convertible forms. In 2+2 form, it is very stiff at 25,000 N·m (18,400 lb·ft) per degree—about twice the figure for the convertible Elise. "Stiffness is based on wheelbase," said Wood. "The Evora's is 2575 mm and the Elise's 2300 mm, so for that [latter] car, some 12,500 N·m per degree is fine."
Carbon fiber is not used in the chassis. Explained Wood: "It might have been thought that the next stage of the bonded structure we use for the Elise could be bonded aluminum and carbon composites, much like the work Lotus Engineering did for the Aston Martin Vanquish, but the cost of the material remains very high and certainly too much for the price range (about $100,000) of the new car."
So Lotus has stayed just with aluminum. However, the mechanical fixing techniques have changed. The Elise’s bonded structure uses screws, but the Evora has rivets. "This is a quicker and more cost-effective solution," stated Wood.
The result, he said, is a "very crashworthy car." Extremely strong longerons extend at the front of the chassis and can be unbolted following an impact.
The composite body is of glass-reinforced plastic with a 2-mm (0.08-in) panel thickness.
The suspension—double wishbones front and rear—uses forged aluminum, a first on a production Lotus. "Forging gives us a very stiff wishbone and one that is dimensionally very accurate," explained Wood.
The new coupe has Bosch ABS and AP Racing brakes, the latter vented and cross-drilled with front and rear disc sizes of 350 and 332 mm (13.8 and 13.1 in), respectively.
The Evora’s Toyota 2GR-FEV6 engine is shipped to Lotus in standard form to be fitted with a Lotus T6e engine-management system and a bespoke exhaust. Toyota also supplies the six-speed gearbox. A close-ratio version of the gearbox is under development.
Lotus’s parent, Proton, supported Project Eagle financially, and a small number of Proton engineers worked with Lotus teams. They brought manufacturing experience of certain materials and processes together with their supplier expertise. Among those suppliers were Yokohama for tires and Alpine for the car’s entertainment and navigation system.
It has been said that Lotus "doesn’t do interiors" because so many cockpits have been minimal to the point of being stark. But the Evora has a leather-trimmed cabin and the equipment level expected of a car in its class. The rear seats can accommodate 5th-percentile manikins. Production of the car will start late this year.
Lotus’ CEO Mike Kimberley has said that the company has a five-year model plan; a "supercar" will replace the Esprit in 2011 (Esprit production ended in 2004), followed by another new car, probably of a similar size to that of the current Elise.
Lotus also builds the very-low-volume, all-electric Tesla sports car, and the company is in a strong position to introduce alternative power units on a broader production base.
"The future is definitely electric," said Wood, but he stressed that, in the market generally for the foreseeable future, there would be a wide choice of powertrains.
For electric solutions, battery technology/costs remain a major challenge, he said: "It costs about $1000 per kW·h for an electric car battery. So a 100-mi range really equates to about 25 kW and £25,000. And the life of a battery is questionable."
But with an ideal electric solution at least thinkable now, there just could eventually be a motive power and yet name change in store for Evora—perhaps to E-lysium.