Garrett G-Series II G35-990 62mm Turbocharger

Garrett G-Series II G35-990 62mm Turbocharger — Select Turbine Housing

Part Number: 934123-5001S

The Garrett G-Series II G35-990 is a standard-rotation, dual-ceramic-ball-bearing turbocharger platform rated by Garrett for 550–990 horsepower and 2.0- to 5.5-liter engine applications. Its 62/76 mm compressor wheel is paired with a 68/62 mm Mar-M turbine wheel, providing substantial airflow in the compact G35 frame.

G-Series II updates the original G35-900 with revised compressor aerodynamics that provide up to 10 percent greater compressor flow at peak pressure ratio and peak turbo speed, together with improved efficiency at high airflow. The G35-990 retains compatibility with the established standard-rotation G35 compressor and turbine-housing architecture.

This product is configured by selecting a compatible Garrett turbine-housing option. External-wastegate configurations include the 934123-5001S supercore and the selected Garrett turbine-housing kit. The two internal-wastegate selections use Garrett’s corresponding complete turbocharger assemblies, supplied with the turbine housing and factory-set 0.5 bar actuator already installed.

A supercore-only option is also available for customers who already have a compatible standard-rotation Garrett G35 turbine housing. The 1.01 A/R open V-band housing is the recommended RAD default for broad street-performance use where a V-band turbine inlet and external wastegate are appropriate.

Key Features

• Garrett-rated 550–990 horsepower range
• Garrett reference displacement range of 2.0–5.5 liters
• 62 mm compressor-wheel inducer and 76 mm exducer
• 68 mm turbine-wheel inducer and 62 mm exducer
• Dual ceramic ball-bearing cartridge
• G-Series II compressor aerodynamics
• Up to 10 percent greater compressor flow than the G35-900 at peak pressure ratio and peak turbo speed
• Improved compressor efficiency at high airflow
• Mar-M turbine wheel rated for exhaust-gas temperatures up to 1050°C
• Stainless-steel Garrett turbine housings rated up to 1050°C
• One-piece center housing and backplate
• Twin piston-ring sealing on both sides of the shaft assembly
• Machined turbo-speed-sensor provision
• Oil restrictor and two water fittings included with the supercore
• External- and internal-wastegate configurations available
• Open V-band, open T3, and divided T4 turbine-inlet options
• Clockable center-section-to-turbine-housing connection on non-wastegated variants

Kit Includes

• 934123-5001S — Garrett G-Series II G35-990 standard-rotation supercore
• Selected Garrett standard-rotation turbine-housing kit when an external-wastegate configuration is ordered
• Garrett turbine-housing connection hardware and gasket kit supplied with the selected turbine kit
• Garrett oil-restrictor fitting supplied with the supercore
• Two Garrett water fittings supplied with the supercore
• For an internal-wastegate selection, the corresponding complete Garrett turbocharger assembly with turbine housing and factory-set 0.5 bar actuator

Technical Specifications

Compressor

• Compressor-wheel inducer: 62 mm
• Compressor-wheel exducer: 76 mm
• Compressor-wheel trim: 65
• Compressor-housing A/R: 0.72
• Compressor inlet: 4-inch hose connection
• Compressor outlet: 2-inch hose connection
• Compressor technology: Garrett G-Series II
• Turbo-speed-sensor provision: Machined port; sensor sold separately
• Maximum published turbocharger speed: 140,000 rpm

Turbine

• Turbine-wheel inducer: 68 mm
• Turbine-wheel exducer: 62 mm
• Turbine-wheel trim: 84
• Turbine-wheel material: Mar-M superalloy
• Turbine-housing material: Stainless steel
• Turbine outlet: 90.16 mm / approximately 3.55-inch V-band
• Turbine-inlet options: Open V-band, open T3, or divided T4
• Wastegate options: External wastegate or Garrett internal wastegate

Center Housing, Oil, and Coolant Connections

• Bearing system: Dual ceramic ball bearings
• Oil inlet: Included restrictor fitting with -4AN connection
• Oil outlet: Two M8 × 1.25 mounting holes
• Coolant fittings: Two included -6AN fittings
• Center-housing coolant ports: Four M14 × 1.5 ports
• Center housing and backplate: One-piece construction
• Rotation: Standard / clockwise

Available Turbine Configurations

• 740902-0104 — 1.01 A/R, open V-band inlet, V-band outlet, external wastegate — Recommended RAD default
• 740902-0103 — 0.83 A/R, open V-band inlet, V-band outlet, external wastegate
• 740902-0102 — 0.61 A/R, open V-band inlet, V-band outlet, external wastegate
• 740902-0105 — 1.21 A/R, open V-band inlet, V-band outlet, external wastegate
• 740902-0106 — 0.83 A/R, open T3 inlet, V-band outlet, external wastegate
• 740902-0107 — 1.01 A/R, open T3 inlet, V-band outlet, external wastegate
• 740902-0108 — 1.06 A/R, divided T4 inlet, V-band outlet, external wastegate
• 934124-5001S — Complete turbocharger, 0.83 A/R open V-band inlet, V-band outlet, internal wastegate with 0.5 bar actuator
• 934124-5002S — Complete turbocharger, 1.01 A/R open V-band inlet, V-band outlet, internal wastegate with 0.5 bar actuator
• Supercore Only — No turbine housing

Application Notes

• This listing is for the standard-rotation G35-990. Garrett reverse-rotation supercore 934126-5001S uses a different turbine-housing family and should be listed separately.
• External-wastegate housed variants combine supercore 934123-5001S with the selected Garrett turbine-housing kit.
• Internal-wastegate variants use complete Garrett assembly 934124-5001S or 934124-5002S rather than an unassembled supercore-and-housing combination.
• The 1.01 A/R open V-band external-wastegate configuration is the recommended RAD default for broad street-performance applications using a V-band manifold connection.
• The 0.83 A/R open housings generally favor earlier turbine response, while the 1.01 and 1.21 A/R housings provide progressively greater turbine-flow capacity.
• The 0.61 A/R housing is the most restrictive option and should be selected only where the intended displacement, airflow, and response target justify it.
• The 1.06 A/R divided T4 housing is intended for a properly divided manifold that preserves exhaust-pulse separation.
• A divided housing should not be selected solely on the assumption that twin-scroll construction is inherently superior.
• External-wastegate variants require a separate wastegate, wastegate springs, boost-control plumbing, and any electronic boost-control hardware.
• The internal-wastegate complete assemblies include a factory-set 0.5 bar actuator; an application-specific boost-control strategy is still required.
• The optional Garrett turbo-speed sensor is not included.
• Compatible Garrett speed-monitoring options include sensor kit 781328-0004, sensor-and-gauge kit 781328-0003, and G-Smart Bluetooth module 923586-0003.
• Garrett identifies 140,000 rpm as the maximum allowable turbocharger speed for the G35-990.
• Turbine-inlet weld flanges, turbine-outlet weld flange, downpipe clamp, external wastegate, oil-drain flange, oil-drain line, oil-feed line, coolant hoses, boost-reference fitting, intake plumbing, charge piping, exhaust manifold, downpipe, and application-specific installation hardware are not included unless specifically added to the order.
• Garrett turbine kits include the housing connection hardware and gasket kit; mating exhaust-system flanges are not included.
• This is a universal performance turbocharger and is not supplied as a vehicle-specific installation kit.
• Garrett’s horsepower rating represents potential flywheel horsepower based on compressor-flow testing. Actual output depends on engine airflow, fuel, boost pressure, exhaust backpressure, engine speed, intercooling, and tune.
• Final turbocharger and turbine-housing selection should account for engine displacement, intended power, torque target, exhaust-manifold design, duty cycle, packaging, and desired response.

Emissions and Competition-Use Notice

Unless specifically identified as emissions-legal for the applicable vehicle and application, this product is intended for sanctioned competition, off-road, or other non-emissions-controlled use. Installation or use on an emissions-controlled vehicle operated on public roads may violate federal, state, or local law. The purchaser and installer are responsible for confirming and maintaining compliance with all applicable emissions and vehicle-use regulations.