MX-5 Superlight: Less is More

Inspiration
The world of automobiles and individual mobility is changing towards energy
efficiency, environmental compatibility and uncompromised safety – along with
dynamic attributes and driving fun. In its efforts to offer pure driving enjoyment, while
meeting its ecological and social responsibilities, Mazda has been focusing on weight
reduction as a core base technology. Reducing weight has always been a tradition
with the MX-5 since 20 years and it provided the inspiration for Mazda's latest show
car providing a radical expression of the cult roadster.

This year Mazda celebrates the 20th anniversary of the first MX-5 roadster, which
laid the cornerstone for its Zoom-Zoom brand philosophy – reason enough for our
designers to create a fully-drivable show car, the MX-5 Superlight version. There are
no plans to build this car, but it demonstrates how individual mobility can be
maintained in a way that uses fewer natural resources.

Mazda's European R+D centre in Oberursel has created a show car that represents
the essence of Mazda's fun-to-drive aspect. Based on the brand icon Mazda MX-5
Roadster, the MX-5 Superlight version is a pure, uncompromising two-seat sports car
meant to be affordable to just about anyone. The main challenge for the design team
in creating this study was "to evolve the MX-5, developed to perfection during the last
20 years, to a higher and extreme level," says Project Lead Designer Hasip Girgin.
The result of their efforts is a roadster show car with an exciting design that is
especially lightweight and distilled down to the very basics of sporty driving, that still
manages to provide modern safety technologies. In an increasingly digitalized world,
it creates a linear, direct bond between man and machine. Its conceptual purity
means even better driving dynamics and fuel efficiency. It accomplishes this by
keeping the vehicle below the 1000 kg threshold, a weight that was felt to be almost
unattainable for a modern sports car until now. As a study for lightweight construction
and driving enjoyment, the MX-5 Superlight version is the ideal ambassador for
Mazda's brand values.

Exterior Design
"I've dreamed of building a Mazda MX-5 with this kind of radical form for a long time,"
says Peter Birtwhistle, Mazda Motor Europe's Chief Designer, referring to the project.
"Now that weight reduction has become a dominant factor in automotive
development, the time is ripe for it. We show how lightweight a car today can be."

His design team reduced the MX-5 down to its core attributes to create a pure
roadster. Development of the production model MX-5 focussed on the bond between
driver and co-pilot to the roadster, the car's driving dynamics and its open-top
experience. The goal of the MX-5 Superlight version concept was to strengthen these
bonds even further. By doing this without a windshield, the retractable top and its
frame, designers achieved an important step in this direction. As the concept MX-5
Superlight version, the all-weather production roadster has mutated into a driving
Frankfurt Motor Show 2009 machine that lets sports car enthusiasts enjoy the natural surroundings unfiltered and
tangible. Not only does the wind blow unimpeded during driving, pilot and co-pilot can
also experience the sounds, smells and temperature changes of their immediate
surroundings. And finally, the show car's intense bond between the driver and the
technology of the vehicle gives it a unique closeness that can only be found in
stronger form in the cockpit of a race car.

Mazda designers created special roll-over bars, not only because they are very
sporty-looking, but also to contribute to aerodynamic efficiency. These also make it
clear that roll-over protection is important in this concept. And they prevent wind
turbulence around the heads of the passengers, from whom the law would require
the wearing of helmets while driving.

By removing equipment not vital to driving, and by replacing vital things with
components that support the unique concept of the vehicle, designers sharpened the
character of the MX-5 Superlight version.

Because there is no windshield, for instance, there is obviously no need for wipers.
The roadster show car's completely open design makes the need for outer door
handles, side windows and their openers unnecessary. A single, filigree aluminium,
wide-angle mirror gives a good view of the road behind. It's placed inside an
extension of the bonnet. Front and rear lights are the same as those of the
production model with additional LED lamps at the front, and brake lights at the back
of each roll-over bar, which contribute to the roadster's sporty look.

The lack of a windshield required an extension of the original aluminium bonnet into
the cabin. The attached sheet here is made of lightweight carbon fibre and provides a
hood for the dashboard frame. This also changed the proportions of the body's
design, making the front of the car longer and the passengers seem like they are
sitting further back towards the rear-drive axle, all of which is enhanced by the
massive roll-over bars and their aerodynamic cladding. The MX-5 Superlight version
translates the dramatic proportions of historical race cars into a very modern form.

Interior Design
The purity in design of the exterior also characterizes the interior design, which does
not have aesthetics as ultimate goal, but was conceived to contribute to reducing
vehicle weight. Driver and passenger of the MX-5 Superlight version are greeted by
racing bucket seats made of ultra-lightweight carbon fibre. They are slide adjustable
and upholstered with the same saddle coloured leather as the armrests, the steering
wheel, and the lightweight aluminium shift lever and hand brake. Colour-coordinated
four-point seatbelts hold the driver and passenger firmly in their seats.

The bonnet extension into the passenger cell provides a canopy for the dashboard,
which makes the dashboard look smaller than the production MX-5. Made of
lightweight plastic reinforced with fibreglass, it contains the same instruments as the
production MX-5. These are held in place by a dashboard frame made of lightweight
carbon fibre. Like a purebred race car, the MX-5 Superlight version has an ignition
button in the centre of the dashboard, along with two emergency kill buttons for
immediate fuel and electricity cut-off.

Frankfurt Motor Show 2009
Supplying air and climate control to the open passenger compartment is only
possible in limited form, so the show car has no air conditioning and no fans. Air-flow
is increased when the roadster accelerates, and only small air vents are needed. The
interior is made without any trim. Sound insulation mats and rugs do not meet the
requirements of a purist concept like this and are not used at all.

Also made of ultra-lightweight carbon fibre is the "floating-design" centre console with
iPod® adaptor and the triangular reinforcements in the trimless doors. Driver and
passenger can rest their arms here while driving.

Driving Dynamics
The Mazda MX-5 Superlight version concept is fully-drivable, but there are no plans
to produce it in the near future. Under the bonnet is the cultivated and frugal MZR
1.8-litre four-cylinder engine paired to the production roadster's five-speed manual
transmission. It develops 93 kW/126 PS of maximum power at 6,500 rpm. For an
appealing engine sound, there's a Mazdaspeed cold air intake made of polished and
powder-coated aluminium and a Mazdaspeed exhaust system, both of them specific
to the MX-5 Superlight version. These systems deliver more intake air-flow, and less
exhaust-gas back pressure. The engine sound is designed to suggest an engine with
much higher displacement than the concept actually has. During charge cycles, a
high-resonance bubbling sound in the muffler delivers the exciting sporty sound you
would expect from a very powerful engine.

The show car is designed to provide improved driving dynamics as well, and uses a
four-piston, fixed-calliper brake system with perforated discs that, because of their
size required an increase in track of 50 mm. A specially tuned chassis with a
Bilstein® B16 coil-over suspension and Eibach® stabilisers give the body of the MX-
5 Superlight version a ground clearance that is 30 mm lower than the production MX-
5. Its sporty hydraulic power-assisted rack and pinion steering system is the same as
that of the regular roadster. Its linear steering, coupled to a precise-shifting five-
speed manual transmission with short shift travel, have contributed to the character
of the world's most successful roadster for years. Also from the production model are
the roadster's 205/45 R17 original-equipment tyres and alloy wheels from the 2.0
version, which are some of the lightest on the market today at less than 8 kg.

Body Type Soft top roadster Monocoque
Seating capacity 2
External Dimensions
Overall length mm 4,020
Overall width mm 1,720
Overall height (unloaded) mm 1,110
Wheelbase mm 2,330
Track front/rear mm 1,540/1,545
Ground clearance mm 106
Engine Type MZR 1.8-litre Petrol
Max. Power kW/PS 93/126 at 6,500 rpm
Max. torque Nm 167 at 4,500 rpm
Transmission 5-speed manual
Front/Rear Suspension Double wishbone/Multilink
Damper (front/rear) Bilstein® monotube
Tyre size 205/45 R17
Brake Type front/rear Ventilated discs/Solid
discs
Brake Diameter (front/rear) mm 300/280
Performance
Acceleration 0-100 km/h * s 8,9
Fuel Consumption (combined)* l/100 km 6,3
CO2 emissions (combined) * g/km 150
Min. kerb weight (without driver) kg 995

Boxes
Building the Show Car
The task sounded challenging and time was short. After the decision was made to
present a radical Mazda MX-5 Superlight version show car at the IAA in 2009, Peter
Birtwhistle had only three months to complete it. He quickly formed a five-person
team – including Hasip Girgin, Luca Zollino, Nigel Ratcliffe, Maria Greger und
Luciana Silvares – which began by designing the cockpit.

There was not enough time for small-scale modelling. The designers put their ideas
to paper, decided which were best, then modelled these directly onto a full-scale clay
model. The cockpit was created together with the interior door braces. All
components were then digitalized. This data was sent to an external studio for
prototype build, where the parts of fibreglass-reinforced plastic and carbon fibre were
made and later fitted. This method was also used to create the centre console with
gear shift lever and hand brake.

Parallel to this, a production MX-5 Roadster with an MZR 1.8-litre powertrain was
stripped of all components that would later be replaced. Under the leadership of
Mazda's design team and chassis engineers, a drivable "blank" of the MX-5
Superlight version was created that weighed well under 1,000 kg, while respecting
the original roadster's ideal 50/50 weight distribution. Mazda test drivers then drove
the roadster around a closed track with experts from Bilstein® and Eibach®, in order
to ascertain the feasibility of the project. The results amazed even the most
experienced engineers: with hardly any re-working, the "light" MX-5 version was an
easy-to-control, safe-driving roadster that displayed agility, great driving dynamics
and acoustical appeal.

Final assembly began with painting the body in white colour, and simply polishing the
original MX-5 aluminium bonnet. Then the racing seats, steering wheel, gear shift
lever and hand brake were upholstered in leather and installed in the show car. This
was followed by the installation of all previously-built carbon fibre components. And
at the end, Mazda designers installed the centre console, the dashboard and
instruments, seatbelts and roll-over bars.

Frankfurt Motor Show 2009
Weight Saving Measures in Detail
Less is more! This was the formal process that Mazda designers followed when
building the MX-5 Lightweight Version at Mazda R+D studios in Oberursel, Germany.
All components that were not absolutely required for driving were put on the scales.
Safety components were left untouched. Weight savings, by either elimination or
replacement, were undertaken on the following components:

• Windshield with frame and wipers
• Retractable soft top and folding frame
• Side windows including window openers
• Outer door handles and side mirrors
• Audio system
• Interior trim, rugs and sound insulation
• Production-model seats
• Air conditioning system, heat exchanger and ventilation system
• Dashboard frame
• Centre console
• Gear shift lever
• Hand brake lever
• Armrest between the seats

History of Mazda MX Concept Cars
The MX-5 has benefited from different concept cars through its 20 years history. In
2000, Mazda's American design studio created the Miata Mono-Posto Concept for
the SEMA show. An earlier step in the direction of a more radical MX-5 was taken by
Mazdaspeed in Japan, which created the Roadster MPS Concept in 2001. This idea
was reinterpreted in 2004 with the Mazda Roadster Coupe TS Concept, which had a
classic Italian coupe shape based on the roadster.

And finally, in 2003 the design study Mazda Ibuki was built that hinted at the third-
generation MX-5, which was launched two years later. Not only did Mazda Ibuki have
extremely small overhangs and the more austere design language of the later
production model, it also anticipated some major conceptual changes. For instance,
the drive assembly of the concept was positioned lower and further toward the middle
of the vehicle, for a lower centre of gravity and an equal weight distribution over both
axles. The production car that appeared later would boast an ideal 50:50 weight
distribution front and rear, and deliver excellent handling attributes.