Replacement automatic torque biasing differential. The Automatic Torque Biasing Helical LSD differential is Quaife's unique patented design for the ultimate TVR differential, and is an after-market differential that provides smooth, constant traction for racing or slippery road conditions. Quaife ATB Helical LSD differentials have been used in a wide array of applications, from Formula 1 cars to emergency and public utility vehicles, where all weather mobility is essential, and where the product must perform in the most demanding of conditions. The characteristics of the differential are that it progressively locks as torque increases; there are no plates or clutches to wear out, as the more conventional limited-slip designs incorporate. Quaife Engineering also offers their ATB Helical LSD differential with a limited lifetime warranty as a demonstration of the quality of the product. The Quaife Automatic Torque Biasing Helical LSD Differential enables your TVR to accelerate quicker and corner faster. How? Simply by getting the power to the ground! The Quaife differential powers both drive wheels under nearly all conditions, instead of just one. With an normal open differential, fitted as standard on most TVR, much precious power is wasted through wheel spin under acceleration. This happens because the open differential shifts power to the wheel with less grip - along the path of least resistance. The Quaife differential, however, does just the opposite. It senses which wheel has the better grip, and automatically biases the power to that wheel. It does this smoothly and constantly, and without ever completely removing power from the other wheel. In cornering, while accelerating out of a turn, the QUAIFE biases greater power to the outside wheel, reducing inside-wheel spin. This allows the driver to begin accelerating earlier, exiting the corner at a higher speed. The Quaife differential also controls loss of traction when the drive wheels are on slippery surfaces such as ice and snow or mud, providing the appropriate biased traction needed to overcome these adverse conditions. The Quaife ATB Helical LSD differential provides constant and infinitely variable drive. Power is transferred automatically without the use of normal friction pads or plates seen in other limited-slip designs. The Quaife ATB Helical LSD differential's unique design offers maximum traction, improves handling and steering, and puts the power where it is needed most. A definite advantage, whether you are on the track or on the street. The Quaife differential is extremely strong and durable, and since it is gear-operated, it has no plates or clutches that can wear out and need costly and regular replacement. There is no maintenance required to the unit, so once installed the unit can be forgotten, apart from the better road responses. The Quaife differential is great for road driving or racing. Racers don't have to put up with locking mechanisms or spools that tear the steering wheel out of their hands when cornering. Because it behaves like an open differential during ordinary driving, street drivers will have trouble telling it's there until pushing the cars towards its limits. The Quaife differential is proven in everything from SCCA Rallying to drag racing and Formula 1. It provides autocrossers with such an advantage, it has become "required" equipment for a winning effort. This unit fits all the current range and TVR Chimaera and Griffiths from 1997 onwards with the BTR differentials. This particular ATB replaces the Hydratrak unit. See TVR RQDH3M in related parts for ATB to fit open or cone type BTR differentials.