Looking at a compressor wheel, the exducer is the "major" diameter. For a turbine wheel, the exducer is the "minor" diameter. The exducer, in either case, is where flow exits the wheel. Compressor wheel exducer diameter is incorporated into Garrett GT-series nomenclature: The "60" in the GT2860RS for example, has a 60mm compressor wheel exducer diameter.

turbobygarrett.com

TurboMaster is a company devoted exclusively to the turbocharger's business since its foundation in 1980, i.e. more than 35 years of experience, knowledge and service backing us up, all of them available for your power needs. 
Distributors of the world best brands GARRETT, HOLSET, HITACHI and TIAL.