819hp Lamborghini Sián Roadster struts out

By CARSIFU | 9 July 2020

BOLOGNA: Lamborghini debuted the Sián Roadster on Wednesday.

It's a limited edition, open-top hybrid super sports car engineered around Lamborghini’s iconic V12 engine. All 19 units are already sold.

Roadster features Lamborghini Sián’s world-first use of super capacitor in hybrid solution and unique materials-science application.

With 819hp on tap, it's the roofless version of the most powerful Lamborghini ever produced.

Screenshot 2020-07-09 at 1.50.38 AM

It's low weight-to-power ratio of 2.0 kg/hp enables it to sprint from 0 to 100kph in under 2.9 seconds and reach a top speed of over 350kph.

The Sián Roadster makes its debut in Blu Uranus, especially selected by Lamborghini’s Centro Stile, which together with the Ad Personam department works with every Sián client to personalise the colour and finish of their Roadster.

The complementary interior is a combination of white with Blu Glauco detailing and aluminum elements in Oro Electrum: new-design air vents produced via 3D printing allows customisation with a client’s initials.

The aerial view of the Sián Roadster is evocative of the iconic periscopio line inspired by the first Countach, running diagonally from the cockpit to the rear and culminating in the aerodynamic airstreamers behind driver and passenger.

Screenshot 2020-07-09 at 1.51.39 AM

The car’s very low front, with integrated carbon fiber splitter, houses the iconic Lamborghini Y-shape headlights.

Lamborghini says airflow is directed through the front splitters and through the front bonnet, through the side air intakes and outlets and over the rear spoiler, with no loss of aerodynamic efficiency from the roadster’s roofless design.

Active cooling vanes on the rear use unique materials-science technology patented by Lamborghini: operation of the vanes is triggered by the reaction of smart-material elements to the temperature generated by the exhaust system, causing them to rotate and providing an elegant and lightweight cooling solution.

Screenshot 2020-07-09 at 1.51.14 AM

The rear of the car incorporates Lamborghini’s evocative hexagon design, including six hexagonal taillights inspired by the Countach. The rear wing is integrated within the profile and extends out only during the driving to enhance the performance.

The low, chassis houses a next-generation V12 powerplant: ‘Sián’ in local Bolognese dialect, meaning ‘flash’ or ‘lightening’, denotes the Sián Roadster’s electrification as part of the future hybrid strategy

The Sián Roadster’s hybrid system provides the highest power possible via the lightest solution, combining the V12 engine with a new powertrain. A 48-volt e-motor, delivering 34hp, is incorporated into the gearbox to provide immediate response and improved performance. The e-motor also supports low-speed maneuvers such as reversing and parking with electric power.

Screenshot 2020-07-09 at 1.50.54 AM

The Sián Roadster sports Lamborghini’s innovative supercapacitor application: a world-first technology storing 10 times the power of a lithium-ion battery.

It's located in the bulkhead between cockpit and engine for optimum weight distribution. Three times more powerful than a battery of the same weight and three times lighter than a battery producing the same power, the electric system with the supercapacitor and e-motor weighs 34kg; it delivers a remarkable weight-to-power ratio of 1.0 kg/hp.

This advanced technology combines with the V12 engine, which incorporates titanium intake valves and is uprated to 785hp at 8,500 rpm. Combined with the additional 34hp from the hybrid system, the Sián Roadster delivers a total of 819hp and reaches a top speed of over 350kph.

Screenshot 2020-07-09 at 1.56.20 AM

The Roadster features a highly sophisticated regenerative braking system, developed by Lamborghini. The symmetric behaviour of the supercapacitor, which contrary to normal Li-Ion batteries can be charged and discharged with the same power, fully charges the Sián’s energy storage system every time the vehicle brakes.

The energy stored is an instantly-available power boost, allowing the driver to draw immediately on increased torque when accelerating away, up to 130kph when the e-motor automatically disconnects, improving the elasticity maneuvers and making it more than 10% faster than a car without this system.

The innovative system also delivers instant acceleration in low gears, with improved traction force provided by the combination of V12 engine and hybrid system.

The moment when deceleration and missing torque is felt during gear changes powered by a traditional combustion engine, is eliminated by the torque upshift fill provided by the hybrid’s e-motor: the driver will feel only the pull backward of acceleration, eliminating uncomfortable jerking movements.