APX is a demonstration of Lotus Engineering’s innovative VVA architecture. The first production car from this
technology will be the new Lotus mid-engine super sportscar.
It is a 7-seater (5 + 2) four-wheel drive
“Crossover” vehicle powered by a front mounted 300 hp supercharged V6 petrol engine.
Thanks to a weight reduced to 1570 kg and to a power to weight ratio of 191 hp per tonne, the APX can accelerate from 0 to 100 km/h in 5.4 seconds and can reach a top
speed of 245 km/h (152 mph).
Lotus’ “lightweight philosophy” enabled to achieve an estimated combined fuel consumption of 8.7 litres / 100 km (or
32 mpg): many rivals in the same market segment
often consume more than 13 litres per 100 km (22 mpg).
APX is manufactured predominantly from aluminium in the form of high-pressure die-cast
corner nodes, stampings and extrusions. It uses advanced assembly techniques, including
adhesive bonding, self-piercing rivets and flow-drill screws for construction – joining
techniques that Lotus calls Riv-Bonding. Lotus has optimised the use of these technologies
thus significantly reducing the number of mechanical fixings within the monocoque structure. This has reduced the level of investment required in manufacturing equipment.
The whole vehicle is 4697 mm long and 1852 mm wide. Wheel base is 2700 mm and track is 1554 mm (front) and 1556 mm (rear).
According to Lotus, APX is a feasible prototype close to
production that gives a vision of the future of niche vehicle manufacture. APX is production feasible as
all the components can be made cost effectively and in high niche volume (up to around
30,000 per year).
Lotus APX will be unveiled at the Geneva Motor Show.
From the official Press Release:
The brief for Lotus Design was to create a visually arresting “Jekyll and Hyde“ car that fulfilled the needs of practical and flexible everyday transport but also provided the enthusiast with a focused driving machine. As with all crossover vehicles the solution is tailored to a specific niche buyer who will instantly identify with these unique attributes.
Russell Carr, Chief of Design for Lotus explains: “We saw the customer as a sportscar enthusiast who, with a typical family of 2 young children, occasionally wants to carry four or five adults in addition to their children. To facilitate this a third row of fold flat coupe style rear seats are accommodated within the cabin.”
The flexibility of the VVA platform system enabled the Lotus Design Studio to create a highly tailored solution that would meet, both, the complex requirements of the occupant and technical package as well as being aesthetically pleasing. The car has to look and feel like a sportscar but accommodate a 5 + 2 seating package.
Russell Carr explains the exterior design philosophy: “We wanted the design to communicate the driving experience of the car, which is characterised by extreme power, performance and grip. Therefore the form language had to convey strength and velocity whilst looking planted to the road. As with all designs the essences of strength and movement are generated from stance and proportion which are, on this car, characterised by an extreme cab rearward, teardrop like silhouette and prominent wheel arches.
“The illusion of speed is further communicated by a taught, fluid form language within which feature lines and surfaces stretch seamlessly from the penetrative nose to the boat – tail rear end. Power is re- enforced by a prominent hood line, similar to classic front engined sportscars, and flared arches, whilst strength is given by a deep bodyside and coupe style slim glasshouse.”
The brief for the interior of the car was to create an environment with the visual drama of a sportscar but with a high degree of functionality and a contemporary sense of luxury. Russell Carr explains further:
“We started by working with the engineering group to optimise the driving position and major controls. Then we created memorable features and controls that combine intuitive function with a unique design and high quality materials. This is evident in the design of the HVAC control, the start button and instrument pack. The latter communicates the cars sporting personality through a distinctive sports bike look which mixes analogue and digital displays within a high quality aluminium casing.”
The digital screens of the instrument pack have multi-functionality enabling major data, including Satellite Navigation, to be placed logically in front of the driver. Great care was taken in developing the grains, textures and material finishes to ensure an ambience of sportiness and contemporary luxury.
Prior to design release for the manufacture of this vehicle, the project was subject to industry standard engineering processes to ensure a quality product. Industry standard APQP processes have tracked and validated CAE (Computer Aided Engineering – Computer analysis for strength, durability, crash performance, Vibration, Aerodynamics, Fluid Flow etc), NCAP targets for crash, pedestrian impact, torsion, bending and modal stiffness targets, full static and dynamic CATIA V5 DMU (Digital Mock Up – Digital build of the car to demonstrate the vehicle build and prove the fit of each part) to minimise build issues and the full suite of Material and Process simulation and validation to confirm manufacturing feasibility.
This coupled with tolerance analysis, full DFM/DFA (Design For Manufacture/Design For Assembly) and advanced joining technology research has been delivered in a true simultaneous engineering environment. The vehicle build proved very successful with only a handful of build concerns. A number of assembly validation builds were eliminated form the project saving both time and cost essential for niche vehicle projects needing ‘Right First Time’ design and engineering philosophies to overcome tight project constraints.
All significant components and structural items are made from Aluminium. This means that APX weighs in at a sector leading light weight of 1570 kg so even though it is not a Lotus car, it adheres rigidly to the fundamental core values of the Lotus brand of “Performance Through Light Weight”. Of course lightweight structures are Lotus Engineering’s forte and this is the industry recognised area where the greatest improvements in performance and fuel economy can be gained.
The understructure is riv-bonded aluminium, consisting of high-pressure die-castings, stampings and extrusions, and uses advanced assembly techniques, including adhesive bonding, self-piercing rivets and flow-drill screws for construction.
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 suffice to hold the structure together during the adhesive cure cycle, and contribute to the performance of the structure during both static and dynamic impact conditions. 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.
APX is powered by a V6 engine has been designed by Lotus Engineering’s powertrain
division. The directive for Project NEF was to produce a high performance prototype engine
without the need to resort to exotic materials or manufacturing technology, allowing
manufacture around the world.
APX’s engine is a supercharged 3 litre (2996 cc, Bore: 88 mm, stroke: 82.1 mm) V6 DOHC
engine, mounted longitudinally in the front of the vehicle.
Performance of the engine is maximum power of 224 kW (300 hp, 304 PS) at 6250 rpm and a
torque of 360 Nm at 4500 rpm.
Like the vehicle, the engine not just a Lotus Engineering concept, but a feasible prototype
close to production, however it is not a concept indicating a strategic powertrain
direction of Lotus Cars. The engine is production feasible and it is expected that the
commercialisation of this engine will be of interest to the automotive clients of Lotus
Simon Wood, Director of Lotus Engineering explains the rationale behind building APX: “the
first production car from Lotus to use the Versatile Vehicle Architecture will be the new mid
engine “super sportscar”, which will go into production in 2008. Lotus Cars customers eagerly
await this vehicle that will be a class-leading and phenomenally high performing car. However,
we wanted to demonstrate the true versatility of the VVA technology, and what better way than
to build a type of car that no one would expect from Lotus – a 4-wheel drive “Crossover” vehicle. I am delighted with this vehicle and we believe that this technology and strategy is
what the motor industry must follow to be able to produce niche vehicles efficiently and
Simon Wood continues; “There is already a great deal of interest in both APX and VVA
technology from our client base and we will work hard to see how Lotus Engineering can help
them with their strategic product solutions”.