Garrett GT28R - GT2859R - 56 TRIM - 310 HP

Garrett GT28R GT2859R Turbocharger picture Twinturbo Honeywell 760x480

This is the Garrett GT2859R turbocharger. This turbo is common in twin turbo applications. And is also an upgrade turbocharger for the Nissan RB26DETT engines used in the Nissan Skyline R34 GT-R. The Garrett GT2859R is a direct replacement upgrade turbocharger for the stock OEM Nissan RB26DETT GT2556R 702987-7 used in Nissan Skyline R34 GT-R. And is also used for upgrades for other straight 6 and V6 engines.

Garrett GT28R GT2859R Turbocharger picture Twin Turbo Honeywell 440x280

The Garrett GT2859R turbocharger is popular because it will allow you to use higher boost pressures. If you look at the compressor map below you can see that it will give you almost 2 bars of boost. On the compressor map you actually read 3 bar on pressure ratio. That's because we already live in an 1 bar environment. So the total pressure seen on the map is 1 bar + the 2 bars that the turbo will give.

If we look at where in the compressor map the GT2859R turbocharger flows the best we see that it's in the 1 - 1.5 bar boost range. This makes the GT2859R a very popular choice for twin turbo applications because you will get a solid 550 HP with them working together. And because it's a T25 flage turbo it will bolt up right away to you're existing manifold if you are looking for an upgrade.

The GT2859R alone will work well all the way down to 150 HP and will give you 310 HP if needed. The recommended engine sizes for the GT2859R turbocharger are 1800cc to 3000cc.

Model: 707160-9 (with wastegate actuator) and 780371-1 (without wastegate actuator)
CHRA: 446179-65

Bearing: Ball bearing
Cooling: Oil & Water cooled bearings
Compressor
Inducer: 44.5 mm
Exducer: 59.4 mm
Trim: 56
A/R 0.42

Turbine
Wheel: 53.9 mm
Trim: 62
A/R: 0.64
Wastegated
Turbine Flange: T25
Turbine outlet: Unique "compact" 5-bolt pattern 

Turbine Housing Options
Part Number: 430609-230
A/R: 0.64
Wastegated

Part Number: 430609-231
A/R: 0.86
Wastegated

Now if you look at the dimensions of the turbine you might notice it's identical to the Garrett GT2554R and GT2854R turbocharger. And it almost is, but you will get more turbine housing options with the GT2859R. Also the turbine outlet flange have a unique compact design to it, so it will not work with the other GT25R flanges or other traditional T25 5-bolt flanges. So an special downpipe flage is needed.

Garrett GT28R GT2859R Turbocharger picture 8 Honeywell 1075x806

The GT2859R Turbine housing is also cast from high-nickel "Ni-Resist" material for extreme applications. And the turbine wheel is cast from "Inconel" so it will take alot of heat and abuse. Also it has the T25 turbine inlet flange with threaded bolt holes instead of traditional through holes.

Garrett GT28R GT2859R Turbocharger picture 7 Honeywell 1075x806

Garrett GT28R Turbocharger GT2859R Compressor Map 56 Trim 310 HP Honeywell 450x600

Garrett GT28R Turbocharger GT2859R Turbine Map 56 Trim 310 HP Honeywell 710x550

Garrett GT28R Turbo GT2859R Dual Ball Bearing Measurements in MM Turbocharger Flanges Diameter Turbo Flange Honeywell 1496x1977

Click for bigger pictures.

The GT2859R use the Standard T25 oil drain flange.
Oil inlet 0.4375IN - 24 Thread for 6.35 Tube Inverted flare connection PER SEA J512 Oil inlet
Oil outlet 2 x M8x1.25 13.5 oil outlet
Water connections thread M14x1.50

Garrett GT28R GT2859R Turbocharger picture 6 Honeywell 1024x768

Garrett GT28R GT2859R Turbocharger picture 4 Honeywell 1024x768