Lamborghini likes to consider the powertrain one unit of the car. With this in mind, engineers created a new transmission to work in conjunction with the newly developed engine. The seven-speed robotized gearbox is referred to as an Independent Shift Rod design. It uses four shifting rods that allow the next gear to be selected while you're still in a different gear. The transmission uses only one clutch; a departure from current crop of DSG gearboxes in most cars. The syncros are constructed of carbon fiber and the ISR transmission is said to be lighter than a DSG and smaller than a traditional manual. Lamborghini says the ISR Transmission will crack off upshifts in 50 milliseconds, roughly 40% faster than the old E-Gear transmission. The all-wheel drive system is also upgraded. It uses a Haldex 4 coupling to send power to the front wheels when needed. The rear axle uses a mechanical limited slip differential, while the front uses an electronic system controlled by the car's ESP computer.
Building a Strong Core
The biggest advancement in the Aventador may be at its very core. While previous Lamborghinis have been constructed using steel and aluminum, the new car is the first mass production Lamborghini to use a full carbon-fiber monocoque. The entire passenger compartment is built using pre-preg carbon-fiber composite with aluminum subframes front and rear. The entire chassis weighs in at 505 pounds. The new construction methods are also said to give the Aventador a 70% stiffer chassis than the Murcielago at 35,000 Newton-Meters per Degree of Deflection. For a comparison, the Countach measured in at 2600 NM/Deg. The Aventador's dry weight is 3472 pounds. The stripped out Murcielago Super Volce weighed 3450 pounds dry, but comfort was certainly sacrificed to get to that low weight. The standard LP640 weighed in at 3670 pounds dry and just over 4000 pounds ready to roll.