Turbocharger Components

Has the shaft started to develop play, or do you want to change your turbo's response without replacing the whole unit? In this category we bring together turbine housings, compressor housings, CHRA units and spare parts such as rebuild kits, flanges and brackets. It is for you if you want to rebuild, upgrade or adapt an existing turbo.

What the individual turbo parts do

Broadly speaking, a turbo consists of three main parts. The turbine housing directs the exhaust gas onto the turbine wheel, and the compressor housing collects the compressed air from the compressor wheel. The CHRA unit – the centre bearing assembly with shaft and wheels – connects the two. In addition to the housings, you will find items such as rebuild kits from BorgWarner, outlet flanges and actuator brackets.

How to choose a turbine housing and compressor housing

The housing's A/R ratio typically affects when boost comes in and how much flow the turbo can deliver at high revs. A smaller A/R can give quicker response, while a larger one can reduce back pressure at high power. The right choice depends on the engine, power target and use. In this category you will find, for example, a Garrett compressor housing with 0.70 A/R and BorgWarner turbine housings with 0.83 and 1.00 A/R. Also pay attention to:

• flange type on the inlet and outlet, e.g. T4 and single or twin scroll
• wheel size, so the housing matches the turbine wheel or compressor wheel
• direction of rotation and clocking relative to the space in the engine bay
• whether the housing has an integrated wastegate or an external wastegate is required

Fitting, compatibility and maintenance

The parts must match the specific turbo series. A housing for a BorgWarner S300SX will not necessarily fit another model, so check the part number, wheel dimensions and flanges before you order. When you replace the CHRA or bearings, clean oil lines and correct oil supply are important. Worn bearings can be caused by contaminated oil or lack of lubrication, so also consider new turbo oil and water lines. In this category you will find brands including Garrett, BorgWarner, TiALSport, Forced Performance and Turbosmart.

Frequently asked questions

Can I replace just the turbine housing on my turbo?

This is often possible if the housing is made for the same turbo series and wheel size. Check the A/R, flange and wheel dimensions for the specific part number. A different housing can change response and boost, so the engine management will typically need to be adjusted.

When does it make sense to replace the CHRA unit rather than the whole turbo?

If the housings are undamaged and the problem lies in the bearings, shaft or wheels, a new CHRA can be an alternative to a complete turbo. Make sure the unit fits your existing housings.

What does A/R mean on a turbine or compressor housing?

A/R describes the ratio between the housing's passage area and the distance from the centre of that area to the centre of the wheel. The value typically affects response and flow, but the right value depends on the engine, wheel size and power target.

What should I check before fitting a rebuilt turbo?

Change the oil and oil filter, clean or replace the oil lines, and prime the bearings with oil before the first start. Also check the intake for foreign objects, as debris from previous damage can destroy the new wheels.