Garrett GTX4088R Turbochargers

What the Garrett GTX4088R is

The GTX4088R is a Garrett GTX-series turbo with the original GTX compressor wheel and a dual ceramic ball bearing cartridge: a 65 / 88 mm, 54 trim compressor wheel in a 0.72 A/R housing and a 77 / 68 mm, 78 trim turbine wheel, rated at 460 to 850 horsepower on engines of 2.0 to 6.0 liters (840 hp in Garrett’s archive index), with a maximum speed of 125,000 rpm. Garrett sold it as a supercore (825614-5005S) with divided T4, free-float turbine housings in 0.95 and 1.19 A/R. It is now in Garrett’s archive of models no longer in production, and Garrett names the G-Series G40 (G40-900 and G40-1150) as its replacement.

This page lists the GTX4088R supercore, complete turbos with divided T4 (0.95, 1.19 A/R), undivided V-band (0.89 A/R) and T3-inlet turbine housings, a version without turbine housing, 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 GTX4088R page (archived) · Garrett turbo archive index · Garrett: G40 launch · Garrett: Turbine Housings 101

GTX4088R 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.