Lamborghini has revealled
more technical details of the Geneva-bound Murciélago
replacement, the LP700-4, detailing that the extensive
use of carbon fiber-reinforced polymer technology
throughout the car that results in the use of an
entirely carbon fiber composite monocoque.
The cell of the future Lamborghini flagship sports car
is made entirely from carbon fiber and has been designed
as a monocoque structure. The load-bearing structure of
the vehicle is engineered as a “single shell” that
functions physically as one component, thus taking full
advantage of the extreme rigidity of CFRP. Formula 1
race cars have been built using CFRP monocoques for many
years – and have proven their crash worthiness time and
again. The same applies to road-going sports cars
featuring monocoque technology – the carbon fiber
occupant cell functions like an extremely safe roll
cage.
Construction offer many advantages
Of course, the term “single shell” applies only in the
descriptive sense – the new Lamborghini monocoque is
made from a series of individual parts with specific
functions, such as stiffening elements made from
Braiding technology, that is one of the best technology
to manage energy adsorption in case of crash. After the
curing process, however, this structure functions as a
single component – including the base section known as
the tub and the complete roof. The full monocoque
solution offers advantages which other processes, like a
tub where a metal roof structure is attached in a
conventional manner, cannot realize. That’s why
Lamborghini chose the full monocoque, which weighs only
147.5 kilograms (324.5 lbs).
Rigid construction
Superior passive safety is only one benefit of the
extreme rigidity of a full carbon fiber monocoque - very
high torsional rigidity is another. The monocoque is
connected at the front and rear with equally rigid
aluminum sub-frames, on which the suspension, engine and
transmission are mounted. The entire body-in-white of
the future V12 model weighs only 229.5 kilograms (505
lbs) and boasts phenomenal torsional rigidity of 35,000
Newton meters per degree of twist. This guarantees a
superb feeling of solidity, but, more importantly,
extremely exact wheel control with excellent steering
precision and sensitive feedback. For the dedicated
driver, both are essential for truly enticing driving
pleasure. The new Lamborghini flagship responds to the
most minute steering input with the stunning precision
of a perfectly balanced race car.
Depending on the form, function and requirements of the
individual elements, the Lamborghini development team
selected from three main CFRP manufacturing methods
within its technology tool kit. They differ not only in
their production processes, but also in the type of
carbon fiber and its weave and, most importantly, in the
chemical composition of the synthetic resin used.
Resin Transfer Moulding (RTM): In this process the
carbon fiber mats are preformed and impregnated with an
exact amount of resin. Afterwards, they are cured under
heat while the part is in the mold. Lamborghini has
achieved a major breakthrough by further developmening
this method. Using the patented “RTM-Lambo” process, the
final mold is no longer a heavy, complex metal piece,
but is made instead from lightweight carbon-fiber parts,
thus making the manufacturing process faster, more
flexible and more efficient. An additional benefit of
the RTM-Lambo process is the low injection pressure that
doesn’t require expensive equipment.
Prepreg – The carbon fiber mats used in this method,
commonly known as prepreg, are pre-injected by the
supplier with a thermosetting liquid resin and must be
stored at a low temperature. The mats are then laminated
in molds and cured under heat and pressure in an
autoclave. Prepreg components are complex to make, but
have an extremely high-quality surface finish (Class-A
surface quality) and are therefore the preferred option
for use in visible locations.
Braiding – These components are manufactured by using
RTM technology. This carbon fiber weave technology is
derived from the textile industry and used to make
tubular components for special applications such as
structural roof pillars and rocker panels. The woven
components are made by diagonally interweaving the fiber
in several layers.
The monocoque of the new V12 super sports car is
constructed using these technologies applied in a series
of special processes. One significant advancement
Lamborghini realized is the ability to use
already-assembled monocoque elements as the mold for the
next step in the process. This makes for a considerable
simplification of the manufacturing process compared
with conventional methods.
Epoxy foam components are also used within the
monocoque. They are placed in strategic points to
increase the stiffness of the monocoque by working as
spacers between the composite layers while also
dampening noise and vibration. In addition, aluminum
inserts are laminated into the front and rear surfaces
to facilitate connection with the aluminum front and
rear sub-frame elements. Because of the complexity of
the materials and process outlined above, Lamborghini
decided to produce its new monocoque completely
in-house, managing one strategic step in the production
process.
Quality control is an absolutely crucial factor – every
single monocoque is measured to exacting tolerances of
only 0.1 millimeters, facilitating the extreme precision
of the overall vehicle. Quality control starts with the
purchase of the carbon fiber parts. Every delivery of
carbon fiber is certified and the material is checked
regularly for compliance with quality standards.
Lamborghini worked together with its suppliers to
develop a world-exclusive fiber and resin system for its
RTM technology. Ultimately, these materials and
processes constitute an important part of Lamborghini’s
worldwide leading expertise in the field.
Carbon composite materials
These materials made from CFRP combine the lowest
possible weight with excellent material characteristics
– they are very light, extremely rigid and exceptionally
precise. Furthermore, CFRP materials can also be formed
into highly complex components with integrated
functions. This reduces the number of individual parts
when compared to traditional metal construction – thus
enabling further weight reduction. Lighter cars have
lower fuel consumption and fewer CO2 emissions. Most
significantly, however, it improves the power-to-weight
ratio – the deciding factor in the overall feel and
performance of a sports car. A super sports car built
using CFRP accelerates faster, has superior handling and
better braking.
