Of all the models making their world debut at the 2011 Geneva Motor Show, Lamborghini’s Aventador LP 700-4 could claim top honors for new technology.
Not only does it have a newly developed carbon-fiber monocoque, but also there is a new V12 engine producing 515 kW (691 hp) at 8250 rpm, a pushrod suspension, and a freshly developed ISR (independent shifting rod) transmission from Oerlikon Graziano that can swap ratios in 50 ms.
“The Aventador is a jump of two generations in terms of design and technology; it is an entirely new project, extreme in its design and performance,” said Lamborghini President and CEO Stephan Winkelmann.
Of all its technology, it is the car’s monocoque (tub and roof) that is arguably the most significant (it will be detailed in another AEI article soon), giving the car the sort of benefits in terms of weight, stiffness, and torsional rigidity that are experienced in the latest F1 designs. Having a mass of 147.5 kg (325 lb) and providing 35,000 N·m (25,000 lb·ft)/degree torsional stiffness, it was developed at Lamborghini’s Sant’Agata Bologna composites facility headquarters and benefited from cooperative work with Boeing among other partners.
Winkelmann said the car owes much of its inspiration for aesthetics and design philosophy to 21st century jet fighters. He underlined the fact that Lamborghini’s application of technologies necessary for the highest standard carbon fiber reinforced plastic (CFRP) production, together with the ability to achieve targets quickly, were due to the company’s broad spectrum of in-house capabilities from 3D design to manufacture and validation. It has patented several technologies.
The monocoque of the Aventador (named after a fighting bull) has been designed to function physically as one component and incorporates braiding technology to enhance crash performance. The tub and roof are bonded in a curing process using fewer than 10 screws to become a single shell.
Braiding is used for some components using RTM (resin transfer molding) technology. A carbon fiber weave, it is used for tubular components including roof pillars and rocker panels. The monocoque is linked to front and rear aluminum subframes for suspension and engines.
The body-in-white (BIW) mass is 229.5 kg (506 lb). Dry mass of the Aventador is 1575 kg (3472 lb), giving a mass/power ratio of 2.25 kg/hp. Zero to 100 km/h (62 mph) acceleration time is 2.9 s.
The dry-sump V12 engine (designated L539) is described by Lamborghini as being “completely new.” Capacity is 6.5 L and, again, as it was with the whole car, powertrain weight savings was a central issue.
Its cylinder bank angle is 60° and the engine measures 665 mm (26.2 in) in overall height, including its intake system (which incorporates four individual throttle valves). Width including the exhaust manifold is 848 mm (33.4 in) and length is 784 mm (30.9 in). Engine mass is 235 kg (518 lb).
The V12’s crankcase is open-deck and uses aluminum-silicon alloy with steel cylinder liners. Cylinder spacing is 103.5 mm (4.07 in). Stroke is relatively short at 76.4 mm (3.01 in). Bearings for the forged and nitride-hardened crankshaft have a mass of 24.6 kg (54.2 lb). Each of the engine’s two cylinder heads is also manufactured from sand-cast aluminum-silicon alloy. The compression ratio is 11.8:1—high by any standards for a gasoline engine. Valve timing—inlet and outlet—is electronically controlled.
The engine is positioned 60 mm (2.4 in) lower than that of the car the Aventador replaces, the Murciélago. The dry-sump unit has eight scavenger pumps to suck oil out of the lower bedplate fastened to the crankcase; pressure and scavenging losses are said to be reduced by around 50%.
The inside of the engine’s intake system housing is extremely complex. The optimum intake path for any given load and engine speed is facilitated by two flaps, several channels, and one bypass. The payback is a well-rounded torque curve and refined pulling power throughout the rev range, claims the company. Maximum torque is 690 N·m (509 lb·ft) at 5500 rpm. CO2 emissions are 398 g/km, and combined fuel consumption is 17.2 L/100 km.
Aural signature has always been important for any Lamborghini, but it is now linked to achieving reduced emissions. The Aventador has a hydroformed and thermally insulated 3-into-1 system incorporating three precatalytic converters close to the engine and two main converters immediately ahead of the muffler casing. In fact, there are a pair of mufflers, one low- and one high-volume. The engine management system regulates a valving system depending on how the car is driven (city or open road) to control—or enhance—the decibels.
The new car’s 70-kg (154-lb) ISR transmission is the result of a significant design and development program by Oerlikon Graziano in Italy and partner Vocis Driveline Controls in the U.K. It is a servo-actuated mechanical gearbox (a robotized manual) that is lighter than a dual-clutch system. (Use of the latter system might have been expected, as Lamborghini is a member of the Volkswagen Group and, as such, a wholly owned subsidiary of Audi AG, which has several applications of its DSG twin-clutch system.) The result is a relatively “slim line” automated seven-speed gearbox.
To reduce shift times, the gear wheels from second and third are separate from one another and the shifting sleeves actuated by independent shifting rods. The shifting action can run virtually in parallel; as one shifting rod disengages one gear, the second rod can engage the next gear. The movements partially overlap, and the physical distances involved in shifting are reduced compared to a conventional system. Shifting time reduction compared to the Lamborghini Gallardo’s e-gear transmission is said to be some 40%.
The ISR has four shifting rods allied to position sensors. Its synchronizing rings are of carbon fiber. The Aventador is all-wheel drive and is built on a wheelbase of 2700 mm (106.3 in); overall length is 4780 mm (188.2 in), height is 1136 mm (44.7 in), and width, excluding mirrors, is 2030 mm (79.9 in).
Other significant technology on the new Lamborghini includes the use of spring and damper pushrod suspension developed from F1 applications. The car also has aluminum double wishbones and ceramic brakes.
Five-spoke alloy wheels are fitted with Pirelli P Zero tires incorporating pressure monitoring. Safety systems include six airbags.