CHRA/ Core Assemblies
(Centre Housing Rotating Assembly) The CHRA is essentially a turbocharger minus the compressor and turbine housings, incorporating the complete rotating assembly, shaft & wheel, bearing housing and compressor wheel.
Journal Bearings
Fits inside the bore of the bearing housing and prevents radial movement of the shaft & wheel.
Heat Shields
Thin plate that protects & separates the top of the bearing housing from the high temperatures of the exhaust gases. It is positioned between the bearing housing and the revolving turbine wheel.
Free-Float
Is a turbo without a Wastegate. Therefore the turbo is unable to regulate its own boost levels.
Corrected Air Flow
In order to plot the airflow data on a compressor map, you must ensure the flow is corrected accounting for differences that affect air density such as atmospheric conditions.
Compressor Wheels
Radial multi-bladed compressor in a turbocharger that draws in ambient filtered air, compresses it within housing, and then blows it out into the intake of the engine.
Choke Line
Indicates the flow limit and is located on the right side of a compressor map.
Bearing Housings
Cast iron housing, the centre of the turbo that houses the turbine piston ring seal, the journal bearing(s) and the thrust bearing, which are all fed with pressurised oil from the engine.
A/R
A/R (Area/Radius) is a term used to define a geometric characteristic of all turbine and compressor housings.
