Garrett GTX2860R Gen II Super Core (Replaces 836040: Specs, Fitment, and Is It Worth It

The Garrett GTX2860R Gen II Super Core (849894-5001S) is an updated compressor and CHRA assembly for the small-frame GTX performance turbocharger platform, replacing the original GTX2860R Super Core (836040-5002S) with a revised Gen II compressor wheel and housing designed for improved efficiency and a wider usable map. The GTX2860R positions itself in the small-to-mid-frame range of the Garrett GTX lineup, with a 60mm compressor wheel and 56mm turbine wheel covering power targets in the 400-600 horsepower range on high-revving four-cylinder turbocharged engines. The Super Core format -- a CHRA paired with the compressor wheel and housing but without a turbine housing -- allows the turbine inlet, outlet, and A/R ratio to be specified separately to match the engine's exhaust manifold configuration. This guide covers the Garrett Turbocharger GTX2860R Gen II specifications, the upgrade differences between the Gen II and original versions, and the engine platforms and power targets where the GTX2860R Gen II Super Core is the correct selection.

Specifications: GTX2860R Gen II Super Core (849894-5001S)

The GTX2860R Gen II Super Core (849894-5001S) updates the original GTX2860R (836040-5002S) with Garrett's Gen II compressor wheel and housing design. The key specification and design changes in the Gen II platform:

• Compressor wheel: 60mm inducer diameter; Gen II wheel profile with revised blade geometry for improved adiabatic efficiency across the operating map; the Gen II wheel reduces the heat added to the intake charge for a given boost pressure compared to the original GTX2860R, lowering intake air temperatures at equivalent boost and power output
• Compressor housing: Updated Gen II compressor housing with revised aerodynamic design to complement the Gen II wheel; the new housing-wheel combination extends the usable compressor map width, increasing the margin between the surge line and the steady-state operating point for a more stable boost delivery under varying load conditions
• Turbine wheel: 56mm turbine wheel retained from the GTX2860R platform; the turbine side is unchanged in the Gen II update -- builders pair the Super Core with the appropriate turbine housing for their exhaust manifold type and A/R requirements
• Power range: 400-600 horsepower on four-cylinder turbocharged engines in the 1.8-2.5L displacement range; the GTX2860R Gen II operates efficiently on high-revving engines where the compressor map aligns with the mass flow rates and pressure ratios these engines generate at full boost and high RPM
• Part number: 849894-5001S (replaces 836040-5002S); builders sourcing a replacement for an original GTX2860R Super Core or upgrading from the original to Gen II use the 849894-5001S

The GTX2860R Gen II is a Super Core assembly, meaning it includes the CHRA and compressor side but requires a separate turbine housing to complete the assembly. The turbine housing selection determines the inlet flange type and A/R ratio, which are chosen based on the exhaust manifold in the application. The T25 and T28 turbine housing configurations are the common inlet types for the GTX2860R platform, and the A/R ratio selection follows the same logic as the larger GTX and G Series platforms: tighter A/R for spool priority, wider A/R for peak flow on high-displacement or high-RPM applications.

Top Picks: Garrett GTX2860R Gen II

For builders replacing a worn or damaged GTX2860R original Super Core or upgrading from the original compressor wheel to the Gen II efficiency update, the Garrett GTX2860R Gen II Super Core (849894-5001S) is the direct replacement and upgrade path within the GTX2860R platform. Browse the complete Garrett turbocharger catalog for the full GTX and G Series lineup covering the 400-1585 hp range.

Match to the Build

• High-revving four-cylinder turbocharged engine targeting 400-550 hp with moderate injector and fuel system upgrades: The GTX2860R Gen II covers this range on 1.8-2.5L four-cylinder engines where the compressor's 60mm inducer produces the flow rates these engines demand at high RPM and boost; the Gen II wheel's improved efficiency lowers intake air temperature compared to the original at the same power and boost targets, which benefits knock-limited gasoline engines and lowers EGTs on small-displacement diesel applications
• Four-cylinder build replacing a worn or failed original GTX2860R Super Core: The 849894-5001S is the direct Gen II upgrade for any original GTX2860R (836040-5002S) installation; the Gen II Super Core pairs with the same turbine housing already on the vehicle -- the turbine housing does not need to change when upgrading from the original to the Gen II Super Core; the compressor housing and wheel update drops in as a direct replacement in the existing assembly
• Performance build stepping up from a smaller turbocharger to the GTX2860R power range: Builds previously running a smaller turbocharger targeting the 400-600 hp range step up to the GTX2860R Gen II when the smaller turbocharger's compressor map is fully utilized and a power increase requires a larger wheel; the GTX2860R Gen II's 60mm compressor extends the power ceiling while remaining within the small-frame turbine housing sizing that fits many four-cylinder engine applications without significant exhaust manifold modification
• Time-attack or circuit-focused four-cylinder build where intake air temperature affects power consistency: The Gen II efficiency improvement over the original GTX2860R translates directly to lower compressor outlet temperatures at equivalent boost and flow; on applications where intake air temperature rises across a circuit session from sustained high-boost operation, the Gen II's thermal efficiency advantage maintains more consistent power output as inlet air temperature climbs

Signs the GTX2860R Super Core Is Worn

• Compressor wheel contact marks or blade damage visible on inspection through the compressor inlet -- CHRA bearing wear allowing the compressor wheel to contact the housing; audible scraping or grinding from the turbocharger at idle or under boost confirms wheel contact; continued operation with wheel contact accelerates bearing failure and risks catastrophic compressor wheel failure at speed
• Excessive shaft play on the compressor wheel when checked by hand -- the CHRA journal or thrust bearings worn beyond spec, allowing the shaft to move laterally or axially beyond the normal small clearance; a new GTX Super Core has very tight shaft play that is barely perceptible by hand; noticeable wobble or end play indicates bearing wear requiring CHRA replacement
• Oil consumption with blue exhaust smoke at boost -- the CHRA seal ring worn, allowing engine oil to pass into the compressor side and enter the intake charge; blue smoke at boost on an otherwise healthy engine points to turbocharger seal failure; continuing to run a seal-failed Super Core introduces oil into the combustion chamber and can cause pre-ignition on gasoline applications
• Boost pressure below target with no inlet or exhaust leaks confirmed -- the compressor wheel or turbine wheel chipped or eroded from debris ingestion, reducing the compressor's ability to develop pressure; FOD damage to the wheel blades reduces compressor efficiency and output pressure; inspection through the compressor inlet with a light and mirror can reveal chip or erosion damage on the wheel blades

Frequently Asked Questions

Does the GTX2860R Gen II Super Core use the same turbine housing as the original GTX2860R?

Yes -- the turbine side of the GTX2860R Super Core is unchanged between the original (836040-5002S) and the Gen II (849894-5001S). The Gen II update is limited to the compressor wheel and housing. A builder replacing an original GTX2860R Super Core with the Gen II 849894-5001S retains the same turbine housing already fitted to the assembly. Only the compressor side changes in the upgrade. This makes the Garrett Turbocharger GTX2860R Gen II a clean bolt-in upgrade path for original GTX2860R installations where the turbine housing is in good condition and only the CHRA and compressor need to be replaced.

Bottom Line

The Garrett GTX2860R Gen II Super Core (849894-5001S) is the updated replacement and efficiency upgrade for the original GTX2860R on 400-600 hp four-cylinder turbocharged builds. The Gen II compressor wheel and housing deliver lower intake air temperatures and a wider usable map than the original version, with the turbine side unchanged for a direct swap into existing GTX2860R installations.