ISR or Independent shifting rod is the new Transmission type bought on to the stage by Lamborghini. The new unit is laid out as a two-shaft transmission with seven forward gears and one reverse. For especially high durability, the synchronizing rings are made from carbon-fiber. The short shift times are the speciality of this kind of transmission.

What it makes different from a conventional transmission?

In a conventional manual gearbox, be it automated or fully manual, the gear wheels for, say, second and third gears are located side by side. When the driver wants to shift gear, the shifting sleeve with synchronizer unit is moved along the shifting rod from second gear through neutral to third gear. This requires twice the distance and twice the time – second gear has to be disengaged before third gear can be engaged.

This process is significantly shortened in ISR transmission – the gear wheels from the second and third gears are separate from each other and the shifting sleeves are actuated by independent shifting rods. Now the shifting process can run virtually in parallel – while one shifting rod is disengaging one gear, the second shifting rod can already engage the next gear. Because these movements partially overlap and the mechanical distances are considerably shorter, this facilitates a significant saving in shift time. Overall, the Lamborghini ISR transmission shifts around 40 percent faster than the e-gear transmission. And that is already one of the world’s fastest automated manual gearboxes.

What is inside?

The new transmission has four of these independent shifting rods, with sensors constantly monitoring their exact positions. They are operated via hydraulic actuators, with an extremely high system pressure of 60 bar ensuring the necessary operating speed. The system incorporates a total of seven hydraulic valves, with pressure supplied by an electric pump. The double-plate clutch is also hydraulically actuated. All system components are contained within one casing. The total weight of the transmission is only 70 kilograms – a distinct advantage, especially compared with the significantly heavier dual-clutch transmissions from the same category.