Unlike turbochargers designed to suit the stock position and orientation, APS D/R Series turbochargers are supplied as a comprehensive and complete bolt-on system, which includes unique turbine inlet pipe and high flow turbine outlet assemblies, high flow air cleaner assembly and power steering lines. The turbine outlet is designed to bolt directly onto any of the APS exhaust system

Both turbochargers are available in either externally wastegated (upper right) or internal (lower right) variants, with a choice of three turbine housing A/R ratios (flow ratings).

Unencumbered by the limitations of current off the shelf WRX turbochargers, APS has totally engineered a "no-compromise" series of turbochargers from the ground up to match the exact requirements of extreme performance Subaru Impreza engines .

APS has utilized extreme flow 650 horsepower Ball Bearing Turbochargers, rotated to avoid the restrictive standard intake duct in its race cars for many years. However given the torque limitations of the stock drive train, APS has refrained from releasing such hardware to the general public, until now. With the release of the upgraded APS gearbox components, APS believes the time has come for the extreme flow, maximum power producing hardware to be available to all!

Demands for improving acceleration response and for the reduction of so-called turbo lag are popular amongst performance enthusiasts who wish to take advantage of the enormous gains in power and torque delivered by turbochargers. In addition, bullet-proof reliability is required particularly at high turbocharger boost pressure levels as well as at extreme exhaust gas temperatures commonly found in high performance turbocharged engines.

In order to achieve crisp turbocharger response, a number of advances in turbocharger design have been utilized over the past decade. Primarily through the use of modern metals/ceramics in order to reduce the mass of the rotating assembly. However, significant gains have been made by reducing the friction of the rotating assembly - and this has meant a departure from traditional turbocharger designs.

Traditional turbocharger design employs a conventional plain bearing that runs on a film of oil. This is known as a floating metal bush.