Garrett GT2554R (GT25R) Turbochargers

What the Garrett GT2554R is

The GT2554R belongs to Garrett’s original GT Series, and Garrett calls it its smallest ball bearing configuration. It has a water-cooled center housing (CHRA), a 42 / 54 mm compressor wheel in a 0.80 A/R housing and a 53 / 42 mm, 62 trim turbine wheel in a 0.64 A/R internally wastegated housing, and Garrett sells it as a complete turbo with its actuator (836023-5001S). Garrett rates it at 170 to 270 horsepower on engines of 1.4 to 2.2 liters.

This page lists Garrett’s 836023-5001S, versions with an anti-surge compressor housing and T25 5-bolt, T3 5-bolt (0.48 A/R) or stainless V-band turbine housings, a bolt-on turbo for the Ford Fiesta ST 1.6L EcoBoost, the CHRA and a compressor housing. Garrett’s own guidance on turbine housings: a smaller A/R gives quicker boost response and more turbine power at low engine speed; a larger A/R lets the wheel flow more, with lower back pressure and more power at high engine speed.

Sources: Garrett GT2554R catalog page · Garrett: Turbine Housings 101

GT2554R specifications

Wheel sizes are inducer / exducer, as Garrett publishes them for this model. The turbine housing sizes are the ones on the listings above; the same turbo is sold with several.