March 8th 2010

         "Trends in Modern Car Design - the Lotus Evora"

                               given by Daryl Greig
                Group Chief Engineer, Lotus Engineering

Daryl Greig, the Group Chief engineer - Advanced Concepts, gave a fascinating talk to a packed auditorium with well over a hundred NES/IET members and their guests, on the reasoning behind, the engineering and the development of, the Evora.

Lotus is an expanding international car manufacturer, with over 100 employees in both the far East and North America, in addition to the 400 or more at their Hethel base in Norfolk .

Based on the success of the Elise, and after a couple of false starts, the larger and more up-market 2+2 Evora was designed to fill the gap between the Elise and a true supercar in the most economic and risk-free way. With better accommodation, and the installation of the V6 engine the Evora is still only slightly longer and wider than the Elise, as well as maintaining the ideal weight distribution. This leaves room for an Esprit type car to complete the range in the future.

The Evora uses a development of the same Elise extruded aluminium chassis, with improved occupant space and access with increased strength, hence not requiring excessive theoretical or practical research, which would have been too costly. It has been developed to maximise the traditional Lotus attributes relating to driver satisfaction in its handling and performance. This has been enhanced by careful matching of component and sub-assembly stiffnesses, aerodynamics and manufacturing using FEA, CFD, track testing and wind-tunnel work.

Careful material and fabrication analysis has optimised the materials which are most appropriate in terms of mechanical and financial parameters in the various areas - aluminium for the main chassis, fabricated steel subframe at the back, and the traditional Lotus glass-fibre bodywork - most of which is now made in France. The chassis and body panel bonding techniques were also described, as were some of the improved jigging procedures. The increased number of panels assists precision and repair and keeps tooling costs down. The well-developed bonding techniques accommodate the small variations in parts sizes whilst maintaining rigidity that is significantly enhanced by the bonded screen.

Daryl showed several slow-motion videos of crash testing, and chassis flexing, which were entertaining as well as educational. and demonstrated both the accurate theoretical predictions, and the resulting impact resistance of the well-matched crash zones.

The talk culminated in thought-provoking information on 'whole car life' energy consumption, which suggested that electric vehicles still had some way to go to improve on the well-developed internal combustion engine, and that hybrid vehicles with electric power and diesel 'range-extenders' were Lotus's best fuess for the way forward. Questions were many, on such topics as corrosion, bio-fuels, and efficiency, and we were left with the definite impression that Lotus are still at the forefront of automotive thinking, with many ideas and developments in place to secure a solid future.

The meeting concluded with a lively question and answer session with Daryl Greig demonstrating, with the clarity of his answers, the depth of his knowledge and his obvious enthusiasm, why he is Group Chief Engineer at Lotus. The audience was asked by the Membership Secretary, Nigel Ratcliff, in his vote of thank to show their appreciation of Daryl's tour de force; the audience responded with much enthusiasm.

March 2010