Turbochargers

This category lists complete turbochargers. Most are ball-bearing units sold by frame size and specification rather than as direct replacements for a particular car, so the listing details matter.

Reading a listing comes down to a few items:

• Bearing type: dual ball bearing, ceramic ball bearing or journal bearing. It affects the oil supply the turbo needs.
• Frame and compressor wheel: the wheel is cast or billet, often quoted as inducer and exducer sizes in millimetres, and together they set how much air the turbo can move. Some titles give the maker’s horsepower rating.
• Turbine housing: listed by flange (T3, T4, divided T4 or T6, or V-band), by A/R, and by whether it has an internal wastegate or needs an external one.

Several models can be bought without a turbine housing if you already have one, and some are offered in reverse rotation for twin-turbo layouts.

Check the physical fit before the numbers. The turbine inlet must match your manifold, the outlet your downpipe, and the compressor connections your intake and charge pipes. A housing without an internal wastegate needs a separate wastegate on the manifold, with its own dump or return pipe.

Before first start, prime the centre section with oil and fit a new oil feed and gaskets. Ball-bearing turbos commonly need a restrictor in the oil feed, water-cooled centre sections need coolant lines, and the oil drain must run downhill to the sump without kinks. Set boost and fuelling on the engine management before the car is driven hard.