Quaife ATB LSD F23 RWD VX220/SpeedsterQuaife ATB LSD for RWD F23 VX220 Speedster. (Not Astra G Zafira A Vectra B) The Quaife Automatic Torque Biasing Differential enables your car to accelerate quicker and corner faster. How? Simply by getting the power to the ground! The differential powers both drive wheels under nearly all conditions, instead of just one. With an normal open differential, fitted as standard on most cars, much precious power is wasted through wheel spin under