Apx By Lotus Engineering

Press release here first

APX by Lotus Engineering (APX stands for "Aluminium Performance

Crossover") is the first example of a complete vehicle built on the innovative

Versatile Vehicle Architecture (VVA).

APX is a demonstration of Lotus Engineering's ability to create innovative and exciting, high

performance products through its world class capability in Vehicle Design, Performance

Powertrain Engineering and niche vehicle development, the first production car from this

technology will be the new Lotus mid-engine super sportscar.

It is a 7-seater (in reality a 5 + 2 with the two rear seats being occasional) four-wheel drive

"Crossover" vehicle with a front mounted 300 hp supercharged V6 petrol engine. Weighing in

at just 1570 kg and with a power to weight ratio of 191 hp per tonne, the APX has sportscar

like performance of 5.4 seconds to 100 km/h (5.0 seconds to 60 mph) before reaching a top

speed of 245 km/h (152 mph). These performance figures are as good as the highest

performing 4x4 "Crossover" vehicles from other brands with up to 195 hp per tonne. Crucially

though, whereas those vehicles need higher output engines to compensate for heavy weight,

APX does not. Combined fuel consumption for APX is estimated to be 8.7 litres / 100 km (or

32 mpg) – impressive on its own and more so when compared to its production rivals which

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.

APX is not just a Lotus Engineering concept, but a feasible prototype close to

production; it is not a concept indicating a strategic direction of Lotus Cars; it is,

however, a brilliant demonstration of VVA and the skills of the team from Lotus Engineering

into what is regarded as 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).

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

Engineering.

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

quickly.

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".

APX by Lotus Engineering in more detail

Background

At the Geneva International Motorshow 2005 Lotus Engineering showed the first example of a

VVA understructure. This understructure is the basis for APX.

Traditionally OEMs 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.

Lotus Versatile Vehicle Architecture (VVA) has been developed to bridge a gap in the

investment-volume curve to exploit the benefits of producing at medium volumes but for niche

markets, thereby giving the best chance of business case success and favourable returns.

The key to the VVA architecture is the high-pressure die cast corner nodes that are combined

with bonding, mechanical fasteners, extruded and pressed aluminium. Lotus Engineering is a

world leader in aluminium, steel and composite body engineering, joining techniques, and

vehicle systems integration. The innovative VVA technology offers a fast-to-market, costeffective

approach to differentiated niche products by spreading the development, investment

and bill of materials burden across a range of niche 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, with a combined annual

production rate of up to around 50,000 units. Structural components common to each family

member are arranged in different configurations in each variant around the ingenious corner

nodes.

The great advantage of this technology is that it can be used by one OEM looking to develop a

range of niche products, or by a group of OEMs looking to share investment, but still retain a

high degree of end product separation.

The Engine – 300 hp, 3-litre V6

APX is a front engined and four wheel drive "Crossover" vehicle for occasional off road use.

The V6 engine has been designed and developed by Lotus Engineering's powertrain division.

The directive for the project was to produce a high performance prototype engine without the

need to resort to exotic materials or manufacturing technology, allowing manufacture around

the world.

The supercharged V6 is part of a family of normally aspirated and supercharged high

performance engines which includes 2.2 litre and 3.0 litre normally aspirated derivatives. All of

these engines are at the prototype stage and are production feasible, but are not currently

planned for production.

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 Engineering.

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. It uses a Rootes-type supercharger

with a compact air – to – water Laminova – type charge cooler with separate parallel coolant

system using its own water pump and heat exchangers allowing a charge temperature

reduction of approximately 50 degrees Celcius.

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. 80% of peak torque is between 1500 rpm and maximum revs

of 6500 rpm.

Like all products from Lotus, it follows the adage of "performance through light weight", in that

the engine weighs just 171 kg (fully dressed, dry weight). This gives a phenomenal specific

output of around 1.31 kW/kg (1.7 hp/kg). Specific performance is 74.6 kW / litre (100 hp / litre,

101.3 PS / litre).

This light weight comes from using cast lightweight aluminium alloy cylinder block (with thin

wall iron liners), aluminium cylinder head, and an aluminium structural oilpan, able to support

the front drive shafts. The oilpan also includes coolant and lubrication channels to the oil

cooler and filter, and an electronic oil level and temperature sensor. Even the pistons are

lightweight – with each on weighing just 454 grams!

The construction of the V6 engine is arranged around the two banks of cylinders at an angle of

75 degrees with a compact cylinder offset of just 32.5 mm. This allows the engine to be

compact, with good vibration characteristics, eliminating any requirement for balance shafts

and the related extra cost, weight, height and complexity.

The Engine Management System uses a state of the art 32 bit ECU processor capable of over

200 million calculations per second. The ECU is Euro IV / E-OBD and LEV/OBDII compliant.

And of course the engine satisfies the European End of Life Requirements (ELV) with respect

to recyclability and recovery.

The V6 engine is an example of extensive research into "engine downsizing by Lotus

Engineering's Powertrain Team. Engine downsizing is the concept of using advanced

technologies to enable a small engine to produce the power and torque of a much larger

engine, with the obvious reduction in fuel consumption and emissions. One of the key

demands of the automotive industry is to produce engines with not only low emissions and

high fuel economy but also extremely good performance. These two demands for performance

and economy are not normally compatible unless there is a significant change in the engine

development strategy.

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

Engineering.

Vehicle Structure:

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.

Understructure Construction

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.

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).

The Design

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 a rare opportunity

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.

Exterior Design:

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."

Interior Design

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.

Example VVA families

The following represents illustrative VVA families that could be achieved:

Family A

Front engine 4WD crossover 15,000 / year

Mid engine RWD supercar 5,000

Front engine RWD coupe 10,000

Front engine RWD saloon 20,000

Family B

Front engine FWD coupe 10,000

Front engine 4WD SUV 25,000

Family C

Mid engine RWD coupe 5,000

Front engine FWD saloon 25,000

Front engine 4WD crossover 30,000 – i.e. APX by Lotus Engineering