Background

The Versatile Vehicle Architecture (VVA), used on the Lotus Evora, is a low volume evolution from the architecture used on the Lotus APX concept and allows for the development of a range of vehicles up to a gross vehicle weight of 1,900 kg. This VVA approach has been designed to be applicable to low and mid-volume applications by utilising low capital investment manufacturing processes. It progresses the Lotus technology from the Elise family of vehicles, using bonded extrusions and folded panels, whilst now incorporating contemporary ease of ingress/egress, build modularity and improved, lower cost repairability. 

Rationale

The innovative VVA technology offers a fast-to-market, cost-effective approach to differentiated niche products by spreading the development, investment and the bill of materials burden across a range of vehicle variants, without the compromise that stems from conventional ‘platform sharing'. The philosophy is based on the commonality and versatility of key elements of the vehicle structure and body systems across a ‘family’ of niche vehicle variants that meet all world homologation and safety requirements.

Traditionally, OEM’s seeking to gain competitive advantage through exciting niche vehicles have to either design a new platform or share one already available. Engineering a bespoke low-volume platform is an expensive, time-consuming solution, whilst sharing a mainstream chassis normally results in compromises in performance and design.

Benefits

The VVA architecture has been designed so that it can be stretched in width, length and height. The strength and stiffness of the low volume VVA chassis can be modified cost effectively by varying the wall thickness of the extrusions, without altering the exterior dimensions. Combining the ability to lengthen or shorten extrusions with the option to tailor the chassis stiffness, vastly increases the number of vehicles that could be developed from this vehicle architecture. Front and mid engine installations have been considered, as well as hybrid and electric vehicle (EV) applications.

The adaptable platform in the new Lotus Evora offers client OEMs a proven high technology way to develop their own exciting niche vehicles.

Construction


The VVA understructure which underpins the Lotus Evora comprises aluminum riv-bonded stampings and extrusions, and uses advanced assembly techniques, including adhesive bonding, self piercing rivets and flow-drill screws for its construction. Lotus pioneered the aerospace technology of bonded aluminum extrusions for use in road vehicles and has successfully developed high performance cars for global engineering clients using this approach. The self-piercing rivets are used in a similar way to spot welding on a conventional steel shell, with the flow-drill screws used for single-sided access on closed sections. Both hold the structure together during the bonding cure cycle, and prevent adhesive joint peeling in the event of a crash. The heat-cured high strength structural adhesive is the main joining medium, and used in combination with the mechanical fasteners, produces an immensely strong, durable joint and a lightweight shell with exceptional torsional stiffness