Garrett GTX3071R Turbochargers

What the Garrett GTX3071R is

The GTX3071R is a Garrett GTX30-series ball-bearing turbo sold in two generations. Garrett rates the current Gen II at 340 to 675 horsepower on engines of 1.8 to 3.0 liters, with an 8 mm dual ceramic ball bearing cartridge, a 54 / 71 mm compressor wheel, a 60 / 55 mm turbine wheel and a maximum speed of 140,000 rpm (supercore 851154-5002S, reverse rotation 844621-5003S). Garrett rated the Gen I at 340 to 560 horsepower, with an 11 full-blade compressor wheel and an oil and water cooled dual ball bearing. Turbine kits come with T3, V-band or T3 internally wastegated inlets in 0.61 to 1.06 A/R.

This page lists Gen II turbos (standard and reverse rotation), Focus ST bolt-on kits, supercores, a CHRA and compressor housings; the title of each listing says which generation it is. 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 GTX3071R Gen II · Garrett GTX3071R Gen I (archived) · Garrett catalog volume 5 (2015, archived) · Garrett: Turbine Housings 101

GTX3071R Gen2 specifications

Wheel sizes are inducer / exducer, taken from the specification published for each part number. The turbine housing sizes are the ones on the listings above; the same turbo is sold with several.