Garrett GTX3071R Gen II Super Core (Replaces 836042): Specs, Fitment, and Is It Worth It

The Garrett GTX3071R Gen II Super Core is a 71mm billet compressor assembly in the GTX Racing Supercore lineup, replacing the previous generation GTX3071R Super Core (836042-5002S) with the updated Gen II assembly under part number 851154-5002S. The GTX3071R Gen II is closely related to the GTX3076R Gen II -- both share the same turbine section architecture, with the GTX3071R using a 71mm compressor inducer compared to the 76mm inducer on the GTX3076R; the 5mm difference shifts the surge boundary and flow ceiling between the two models while keeping the same turbine housing interface. Like the GTX3076R, the GTX3071R Gen II catalog includes both a standard rotation Super Core (851154-5002S) and a reverse rotation variant (844621-5003S). A notable addition to the GTX3071R catalog in this store is the availability of dedicated Ni-Resist reverse turbine housings in two A/R ratios -- 0.61 and .83 -- which are designed specifically for reverse rotation GTX3071R Gen II builds and are sold as complete housing kits. This guide covers the full Garrett GTX3071R Gen II product set, how to choose between standard and reverse rotation, and how this Garrett Turbocharger platform positions relative to the GTX3076R for single-turbo build planning.

Specifications: GTX3071R Gen II Super Core and Turbine Housings

The GTX3071R Gen II catalog covers two Super Core rotation options and two reverse turbine housing A/R options:

Super Core Assemblies:

• Standard Rotation (851154-5002S): Replaces 836042-5002S; clockwise rotation when viewed from the compressor inlet; the standard selection for front-engine, longitudinally-mounted single-turbo builds in conventional scroll-forward orientations
• Reverse Rotation (844621-5003S): Counter-clockwise rotation when viewed from the compressor inlet; for rear-engine, mid-engine, and transverse layouts where standard rotation would route the compressor discharge in an inconvenient direction relative to the intercooler and charge pipe

Reverse Turbine Housing Kits (Ni-Resist, O/V V-Band Inlet / V-Band Outlet):

• 0.61 A/R (740902-0053): Tighter turbine area for reverse rotation builds; faster spool response at the cost of higher backpressure at peak exhaust flow; suited to smaller-displacement engines and builds where boost onset is prioritized
• .83 A/R (740902-0054): Wider turbine area for reverse rotation builds; lower backpressure at peak flow; suited to larger-displacement engines and builds where peak power output takes priority over spool speed

The Ni-Resist material in both turbine housings refers to a nickel-alloyed cast iron with higher thermal resistance and lower thermal expansion than standard ductile iron -- used in turbine housings on builds where sustained high exhaust gas temperatures are expected. Both housings use an Open/V-Band (O/V) inlet, which accepts a V-Band discharge from the exhaust manifold or an upstream compound turbo, and a V-Band outlet for the downpipe. These reverse turbine housings are matched specifically to the reverse rotation Super Core (844621-5003S); the scroll direction in the housing mirrors the reverse rotation compressor orientation. Standard rotation GTX3071R builds pair with standard GTX-series turbine housings sourced through the GTX housing catalog.

The GTX3071R and GTX3076R share the same turbine section, meaning a builder can swap between the two Super Cores without changing the turbine housing. The GTX3076R (851154-5001S) is the correct step when a build's power target or displacement pushes the GTX3071R compressor near its flow ceiling, and no turbine housing change is required to make that compressor upgrade.

Top Picks: GTX3071R Gen II Super Cores and Reverse Turbine Housings

For standard rotation single-turbo builds, the Garrett GTX3071R Gen II Super Core (Replaces 836042-5002S) - Super Core Assembly (851154-5002S) is the current Gen II replacement for 836042-5002S, delivering the updated compressor aerodynamics and bearing specification in the same turbine housing setup. For reverse rotation builds requiring counter-clockwise compressor rotation, the Garrett GTX3071R Gen II Super Core (Reverse Rotation) - Super Core Assembly (844621-5003S) provides the same 71mm Gen II compressor in the reverse-rotation configuration. Reverse rotation builds can source a matched turbine housing in either the Garrett GTX3071R Gen II Reverse Turbine Housing Kit O/V V-Band 0.61 A/R Ni-Resist (740902-0053) for tighter spool response or the Garrett GTX3071R Gen II Reverse Turbine Housing Kit O/V V-Band .83 A/R Ni-Resist (740902-0054) for reduced backpressure at peak output. Builds that outgrow the GTX3071R compressor can step to the Garrett GTX3076R Gen II Super Core (851154-5001S) using the same turbine housing. Browse the complete Garrett GTX Gen II catalog for additional GTX-series options.

Match to the Build

• Standard rotation single-turbo build on a front-engine vehicle replacing a worn or undersized turbo: The 851154-5002S is the direct Gen II replacement for 836042-5002S in the same turbine housing setup; a builder returning for a Super Core replacement receives the Gen II compressor revision and updated bearing specification without changing the turbine housing or any supporting hardware; the GTX3071R covers single-turbo gasoline and diesel builds in the 350-500 hp range depending on engine displacement and boost target
• Reverse rotation build on a rear-engine or mid-engine platform requiring a complete housing kit: The combination of the reverse rotation Super Core (844621-5003S) and one of the two reverse Ni-Resist turbine housings provides a matched reverse-rotation assembly; the 0.61 A/R housing is appropriate for smaller-displacement engines and builds where rapid boost onset is the priority; the .83 A/R housing suits larger-displacement engines and builds where peak power output is the primary concern over spool speed
• GTX3071R build stepping up to GTX3076R for more compressor flow at the same turbine housing: A build running the GTX3071R that is approaching the edge of the compressor map at its current power target can step to the GTX3076R Gen II Super Core using the same turbine housing; both models use the same turbine section and V-Band turbine interface, so no turbine housing purchase is required for the compressor upgrade; the GTX3076R's 76mm inducer extends the surge line and flow ceiling above the GTX3071R's 71mm limit
• Reverse rotation build requiring Ni-Resist turbine housing for high exhaust temperature durability: The Ni-Resist material in the GTX3071R reverse turbine housings provides improved resistance to thermal fatigue and distortion at sustained high exhaust gas temperatures compared to standard ductile iron; builds on high-output engines that produce elevated exhaust temperatures under full-load operation benefit from the Ni-Resist housing's reduced thermal expansion, which maintains tighter clearances and reduces the risk of housing distortion over repeated heat cycles

Signs the Super Core Is Worn

• Bearing noise or shaft play at the compressor inlet -- mechanical wear at the rotating assembly producing vibration or grinding that changes with RPM and boost demand; detectable as radial movement at the compressor wheel in the housing; on a standard rotation build the 851154-5002S is the replacement; on a reverse rotation build the 844621-5003S is the replacement
• Compressor map surge at the power target -- flutter or pressure reversal under wide-open throttle where the current compressor is past its surge line; if the current compressor is a GTX3071R already mapped to its ceiling, stepping to the GTX3076R Gen II Super Core (851154-5001S) is the upgrade path using the same turbine housing; if the build is below the GTX3071R's ceiling and the surge is a wear or contamination issue, the 851154-5002S Super Core replacement restores correct compressor geometry and clearances
• Compressor-side oil ingestion -- shaft seal wear producing an oily film inside the charge pipe between the compressor outlet and the intercooler; progressive seal wear generates increasing oil in the charge air; the Super Core replacement restores fresh seals and bearing specification; both rotation variants address seal wear in their respective configurations
• Turbine housing cracking or V-Band groove distortion on a reverse rotation build -- thermal cycling fatigue at the turbine housing causing the V-Band outlet groove to deform or the housing body to crack; a cracked or distorted reverse turbine housing on a GTX3071R build is replaced with the 0.61 A/R (740902-0053) or .83 A/R (740902-0054) depending on the A/R specification of the original unit

Frequently Asked Questions

How do I know if I need the standard or reverse rotation GTX3071R Gen II Super Core?

Standard rotation (851154-5002S) is correct for almost all front-engine single-turbo builds where the turbocharger mounts in a conventional position with the compressor scroll discharging toward the intercooler in the standard direction. Reverse rotation (844621-5003S) is needed when the turbo mounting position, manifold geometry, or intercooler placement requires the compressor scroll to discharge in the opposite direction -- this is the case on rear-engine builds, mid-engine platforms, and some transverse-engine swaps where standard rotation produces a charge pipe routing conflict. If you have an existing turbocharger, check the compressor scroll discharge direction on the current unit to confirm rotation before ordering.

Bottom Line

The Garrett GTX3071R Gen II Super Core covers single-turbo builds in the 350-500 hp range in both standard (851154-5002S) and reverse rotation (844621-5003S) configurations, with matched Ni-Resist reverse turbine housings available in 0.61 and .83 A/R for complete reverse-rotation build setups. It shares turbine section compatibility with the GTX3076R, allowing a compressor step-up without turbine housing changes when the build outgrows the 71mm compressor ceiling.