Lamborghini has unveiled details of its HPEV (High Performance Electrified Vehicle) hybrid super sports car, LB744. Its new powertrain delivers more than 1000 CV due to the combination of an internal combustion engine with three electric motors and a double clutch gearbox.
The new L545 engine has a capacity of 6.5 liters and is the lightest and most powerful 12-cylinder engine ever made by Lamborghini.
The naturally-aspirated 6.5-liter V12 mid-mounted engine is accompanied by three electric motors, one of which is integrated into the new double-clutch eight-speed gearbox. This is mounted transversely and placed for the first time behind the combustion engine.
A lithium-ion battery replaces the transmission tunnel, powering the electric motors. The electric motors boost power delivery at low revs and can also turn the new LB744 into a purely electric car.
The air intake ducts to the cylinders have been re-engineered to increase the supply of air and guarantee optimal airflow in the combustion chamber. The combustion within the actual engine has also been optimized, thanks to the regulation of ionization in the chamber with two control units: a solution already used in the Aventador and now transferred to the new model.
The new combustion system is also characterized by an increased compression ratio of 12.6:1, and the fluid dynamics of the exhaust have also been improved to reduce counter-pressure at high revs and increase the specific power output.
As well as the internal combustion engine that provides power to the rear wheels, a pair of electric motors now make their debut on the front axle, each supplying traction to one of the front wheels. There’s also a third electric motor positioned above the eight-speed double-clutch gearbox that can supply power to the rear wheels, depending on the selected driving mode and the conditions.
The two electric motors at the front are oil-cooled axial flux units and offer a weight-to-power ratio of 18.5kg from each of the 110 kW units.
As well as providing power to the front wheels, they also have a torque vectoring function, optimizing driving dynamics, and recuperating the energy produced under braking. When in electric mode, the LB744 is front-wheel drive only to optimize energy consumption, while electric drive to the rear axle is activated on demand when needed.
The Lamborghini LB744 is equipped with a lithium-ion high specific power (4500 W/kg) battery pack situated within the central tunnel, keeping the center of gravity as low as possible and ensuring optimal weight distribution. The battery is protected by a lower structural layer and is connected to the front electric motors, the rear electric motor, and an integrated recharging unit.
The battery is 1550mm long, 301mm high, and 240mm wide, containing pouch cells with an overall capacity of 3.8 kWh. When the charge drops down to zero it can be recharged using both ordinary domestic alternating and charging column current up to 7 kW in power, and completely recharges in just 30 minutes. It can also be recharged under regenerative braking from the front wheels or directly from the V12 engine in just six minutes.
Lamborghini has developed a new compact transmission unit, a wet double clutch capable of managing the 725 Nm of torque at 6750 rpm from the internal combustion engine. The development of an eight-speed Double Clutch Transmission (DCT) comes from the desire to create a unit that provides everything needed for sporty driving such as fast gear shifts, while the inclusion of an eighth ratio helps optimize fuel consumption and drivability while cruising.
How the system functions depends on which driving mode is engaged, thanks to an uncoupling mechanism with a dedicated synchroniser allowing the connection to the double-clutch gearbox.
When it is providing additional power to the V12 internal combustion engine, the electric motor is in P3 position, separated from the gearbox, while it moves into the P2 position to recharge the battery at low speeds and when parked, also serving a starter motor.In the P3 position, the LB744 can become an electric four-wheel drive car, depending on the drive mode selected, continuing Lamborghini’s four-wheel drive tradition even with zero emissions.
Reverse gear is provided by the two front electric motors, although if extra momentum is needed the rear electric motor can also kick in, which activates the rear axle and wheels. As a result, the new LB744 can drive all four wheels in zero emission mode even when reversing in low grip conditions.