Blog — how to select A/R

Courtesy of www.TurbobyGarrett.com A/R (Area/Radius) describes a geometric characteristic of all compressor and turbine housings. Technically, it is defined as: the inlet (or, for compressor housings, the discharge) cross-sectional area divided by the radius from the turbo centerline to the centroid of that area (see Figure 2.). Figure 2. Illustration of compressor housing showing A/R characteristic   The A/R parameter has different effects on the compressor and turbine performance, as outlined below. Compressor A/R - Compressor performance is comparatively insensitive to changes in A/R. Larger A/R housings are sometimes used to optimize performance of low boost applications, and smaller A/R...