Alfa Romeo OE torsen type limited slip differential.
Can be retro-fitted without modification to 3L GTV and Spider.
The Q2 is a torque sensing differential that constantly adjusts the torque split between the front wheels so that it is biased towards the wheel with the most grip. When it senses an unloaded wheel start to spin, it transmits torque progressively across the differential to the wheel with greater grip, allowing the driver to accelerate earlier out of a corner and thereby achieve a higher exit speed.
Traction under hard acceleration is superb, especially when exiting a wet roundabout or powering out of an off-camber corner where the standard car is prone to understeer.
The Q2 allows much more throttle to be applied in a corner and the car responds more positively to steering inputs when on the limit of grip under acceleration. It is also noticeable how much the Q2 reduces torque steer, especially in the wet and when the front tyres are worn. Under hard acceleration with the standard open differential, the steering wheel will often tug in your hands as it tracks imperfections and surface changes in the road. With the Q2, the extra grip at the front wheels is immediately noticeable as the car holds its line and feels much more sure footed.