Housings - a/r vs cm² – RHB Turbochargers Inc.

Housings - a/r vs cm²

The industry standards for describing turbine housing size and subsequent flow rate have always been a/r or cm² - but how do these two units compare? Is there some way to cross reference between the two? 

The simple answer is no. One unit is simply a measurement, and the other unit is a ratio of two measurements. The images below will describe the difference between the two units of measurement. 

Despite their differences, neither unit is superior to the other. In fact, both units are required to get the clearest definition of turbine housing volute size and shape at the most technical level.