G-Series II G25-585 48mm Turbocharger
Horsepower: 300 - 585
Displacement: 1.4L - 3.0L
Features
G-SERIES II UNIVERSAL PERFORMANCE TURBOCHARGER
G25-585 | 49mm Turbine
- New compressor aero increases power and performance.
- Up to 10% higher compressor flow compared to G-Series Gen I at peak pressure ratio and peak turbo RPM.
- Direct upgrade path for Gen I customers with just a CHRA swap.
- Utilizes Gen I compressor and turbine housings.
- Standard and reverse rotation configurations.
- Turbine wheel constructed of Mar-M alloy rated up to 1050°C.
- Oil restrictor and water fittings included.
Competitor Frame Size Reference: 4849 (48mm compressor inducer / 49mm turbine exducer)
Read About Turbo System Optimization: A guide to setting up your turbocharger
WARNING: Maximum allowable turbocharger speed is 185krpm. The use of this product above max turbocharger speed is at the owner’s risk, and can result in damage and premature failure. To protect the turbocharger from overspeed when operating, a speed sensor can be installed into the compressor housing to monitor shaft speed. Sensors sold separately. (click here for details)
Performance results of this product are highly dependent upon your vehicle’s modifications and tuning/calibration. The horsepower numbers represented above are calculated based strictly on choke flow of the compressor map (total turbo capability), which represents the potential flywheel horsepower.
IMPORTANT PRODUCT INFORMATION
“Garrett Performance Kits are professional aftermarket products only designed for certain racing vehicles driven on particular racing tracks and shall only be used on racing vehicles that will never be driven on public roads or highways. Garrett Performance Kits are not legal for the use in vehicles on public roads or other roads to which public road law applies. Any vehicle modifications using Garrett Performance Kits are AT YOUR OWN RESPONSIBILITY and AT YOUR OWN RISK. Only use Garrett Performance Kits in compliance with all applicable laws, regulations, and ordinances (including but not limited to emission, noise, operating license, performance, safety, and type-approval aspects). A vehicle modification using Garrett Performance Kits may particularly affect or void a vehicle’s warranty, operating license or type-approval. Moreover, only use Garrett Performance Kits in compliance with all applicable racing and racing track provisions. It is YOUR OWN RESPONSIBILITY AND RISK to ensure that your Garrett Performance Kit fits your vehicle and area of application. YOU MUST ENSURE LAWFUL AND SAFE OPERATIONS AT ANY TIME. You should particularly consult the owner’s manual and service manual of your vehicle. You should also contact your vehicle’s manufacturer to determine what effects modifications may have on important aspects such as safety, warranty, performance, etc. Only install and use Garrett Performance Kits if you have fully read and understood this important safety information and if you fully agree with the terms and conditions set forth therein.”
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G-Series II G25-585 48mm
Reference Data
| Supercore PN | CHRA PN | Rotation | Turbo Reference | Horsepower Rating | Comp Inducer | Comp Exducer | Turbine Inducer | Turbine Exducer |
|---|---|---|---|---|---|---|---|---|
| 934075-5001S | 934074-5001S | Standard Rot | 4849 | 585 | 48mm | 60mm | 54mm | 49mm |
| 934114-5001S | 934113-5001S | Reverse Rot |
| Turbine Kit PN | Rotation | A/R | Inlet | Outlet | Wastegate | Divided |
|---|---|---|---|---|---|---|
| 740902-0069 | Standard | 0.72 | V-Band | V-Band | External | N |
| 740902-0068 | Standard | 0.92 | V-Band | V-Band | External | N |
| 740902-0076 | Standard | 0.72 | V-Band | V-Band | Internal | N |
| 740902-0077 | Standard | 0.92 | V-Band | V-Band | Internal | N |
| 740902-0080 | Standard | 0.49 | T25 | V-Band | Internal | N |
| 740902-0073 | Reverse | 0.72 | V-Band | V-Band | External | N |
| 740902-0074 | Reverse | 0.92 | V-Band | V-Band | External | N |
| 740902-0078 | Reverse | 0.72 | V-Band | V-Band | Internal | N |
| 740902-0079 | Reverse | 0.92 | V-Band | V-Band | Internal | N |
| Turbo PN | Rotation | A/R | Inlet | Outlet | Wastegate | Divided |
|---|---|---|---|---|---|---|
| 934076-5001S | Standard | 0.49 | T25 | V-Band | Internal | N |
| 934076-5002S | Standard | 0.72 | V-Band | V-Band | Internal | N |
| 934076-5003S | Standard | 0.92 | V-Band | V-Band | Internal | N |
| 934115-5001S | Reverse | 0.72 | V-Band | V-Band | Internal | N |
| 934115-5002S | Reverse | 0.92 | V-Band | V-Band | Internal | N |
| * Turbo PN assembled and calibrated with a 0.5 bar actuator | ||||||
G-Series II G25-585 48mm
Compressor Map & Exhaust Flow Chart
Compressor Map
Exhaust Flow Chart
Compressor Map Overlay Explained
The compressor map overlay illustrates the airflow and pressure ratio differences between the previous G-Series Gen I turbocharger and the current G-Series II design. In key operating regions, the G-Series II compressor provides increased airflow capability at comparable pressure ratios, expanding the usable operating range and supporting higher horsepower potential where engine demand allows. The G25-585 has 18% more flow than the G25-550 turbocharger.
To fully realize these gains, ECU calibration is necessary to optimize performance when upgrading from a previous-generation turbocharger.
Engineering & Intellectual Property
Garrett turbochargers are engineered through extensive motorsports and OEM development programs. Garrett’s technologies are protected by a number of intellectual property rights in the USA and other countries, for example by U.S. patents US9850911B2; US10047607B2; US10502263B2.
Gen I to Gen II Upgrade Compatibility
G-Series II turbochargers are designed to support a direct upgrade path for existing G-Series Gen I users. The compressor and turbine housings retain the same contours and interfaces, allowing Gen I owners to upgrade to G-Series II performance by replacing the CHRA while continuing to use their existing housings. (like-model to like-model swaps ie G25-550 to G25-585)
This approach simplifies the upgrade process, reduces installation complexity, and preserves existing hardware investments. As with any turbocharger upgrade, ECU calibration is required to optimize performance and ensure proper operation when installing a G-Series II CHRA.
Turbo Speed Monitoring
This Garrett turbocharger features a fully machined turbo speed sensor port. Monitoring turbocharger shaft speed is recommended to help prevent overspeed and protect long-term durability, especially when operating at higher performance levels. Compatible speed sensor kits are available separately. Use PN 923586-0002 (G-Smart Bluetooth Module / App) or Speed Sensor Kit 781328-0001 (street kit w/ gauge) or 781328-0002 (pro kit w/o gauge)
Why Choose Garrett
Trust the name that’s been powering innovation for over 70 years. Garrett turbochargers are engineered to meticulous standards used in OEM production environments and validated through decades of motorsports and advanced engineering programs. With more than 130 million vehicles powered globally, Garrett delivers performance, reliability, and innovation you can trust.
Engineering Excellence
Garrett’s engineering excellence is built on nearly a hundred years of expertise, innovation, OEM collaboration, and motorsports experience. Since 1955, a global team of more than 1,300 top-tier engineers has developed turbocharger technology using advanced aerodynamic design, materials science, computational fluid dynamics (CFD) modeling, thermal and structural analysis, rotor dynamics, and other sophisticated techniques. From Formula 1 racing programs to direct engineering partnerships with the world’s leading vehicle manufacturers, Garrett’s next-generation turbo technology delivers the airflow, efficiency, durability, and horsepower demanded by modern high-performance applications.
Testing & Performance Validation
Before you bolt them on, Garrett’s turbochargers are meticulously and relentlessly validated through extensive testing. Performance is engineered into every element on both the hot and cold sides, and each design endures burst containment testing, 1,000-hour engine durability cycles, and 500-hour gas stand runs, as well as thermal cycling, fatigue analysis, vibration analysis, bearing testing, and more. Combined with flow-tested compressor and turbine maps, you can be confident your Garrett turbo will withstand extreme boost pressures and harsh operating conditions without compromising reliability or performance.
OEM-Level Manufacturing
Consistent performance requires flawless production execution, and it’s engineered into every step of Garrett’s manufacturing process. Robotic assembly, high-temperature alloy metallurgy, automated rotor balancing, and micron-level precision machining ensure your turbo matches the one on the test stand. Additionally, every rotating assembly undergoes high-speed balancing and micro-inspection, while strict Six Sigma quality control systems, unit-by-unit inspection processes, and dimensional verification provide the standards needed to deliver turbochargers built for demanding performance applications. By maintaining the same quality required by OEMs, Garrett guarantees exceptional out-of-the-box performance.
Global Support Network
Garrett backs its turbo technology with an expansive global network of authorized dealers to support you before, during, and after installation. If you need dedicated technical assistance, help with precise engine-matching, complete product documentation, or a warranty you can count on, Garrett stands behind every turbo it makes so you can enjoy peace of mind with your high-performance purchase. Whether you’re building your first project car or running a professional race program, you can trust that Garrett is committed to being part of your team.
FAQ
Where can I buy the Garrett G25-585 turbocharger?
Use the Garrett Dealer Locator to find an authorized retailer or distributor. Purchasing through an authorized source ensures product authenticity, technical support, and warranty coverage.
Will I need to retune my engine when installing a G-Series II turbocharger?
Yes. Performance results are highly dependent on vehicle configuration and ECU calibration. The increased airflow capability of the G-Series II compressor requires proper tuning to optimize performance, drivability, and durability.
Can I upgrade from a G-Series Gen I turbocharger to G-Series II using my existing housings?
Yes. G-Series II turbochargers are designed to support a direct upgrade path for existing G-Series Gen I users. In many cases, upgrading to G-Series II performance can be accomplished by replacing the CHRA while retaining the original compressor and turbine housings.
What horsepower can the G25-585 support in real-world applications?
The G25-585 is capable of supporting up to 585 horsepower based on compressor flow testing. Actual results will vary depending on engine displacement, fuel type, boost pressure, supporting modifications, and calibration strategy.
How does G-Series II differ from the previous G-Series turbochargers?
G-Series II turbochargers feature updated compressor aerodynamics that provide increased airflow and efficiency compared to the previous generation. These improvements expand the usable operating range and support higher horsepower potential, where engine demand allows.
Why is turbo speed monitoring recommended for high-performance applications?
Monitoring turbocharger shaft speed helps prevent overspeed conditions that can affect long-term durability. G-Series II turbochargers feature a fully machined speed sensor port, allowing users to monitor operating conditions, especially at higher performance levels.
