Introducing the Garrett G-Series II Platform
G-Series II represents the next evolution of Garrett’s high-performance turbocharger platform, building on the proven capabilities of the original G-Series lineup with expanded airflow capability and high-flow efficiency.
Developed for performance builders, tuners, racers, and enthusiasts, the G-Series II lineup is designed to support a wide range of power levels and engine combinations across modern performance platforms.
The platform introduces updated compressor aerodynamics that increase airflow and widen the operating range while maintaining the durability and reliability that Garrett turbochargers are known for.
From responsive drift builds to extreme half-mile exotics, G-Series II expands the performance potential of the Garrett G-Series family while maintaining compatibility with many existing installation configurations.
How G-Series II Builds on the Original G-Series Platform
G-Series II was developed to expand the capability of the original platform with improved compressor aerodynamics, increased airflow, and high-flow efficiency while maintaining a practical upgrade path for existing G-Series users.
Increased Compressor Flow
G-Series II delivers increased compressor flow capability, giving builders additional airflow headroom to support higher performance goals.
Updated Compressor Aerodynamics
New compressor aero technology improves the overall performance potential of the platform and helps extend capability where serious builds demand more.
Better Efficiency at High Flow Rates
G-Series II boost airflow and high-flow efficiency, widening the operating range and supporting more power.
Upgrade Path form Gen I
G-Series II maintains compatibility with Gen I compressor and turbine housings, many Gen I users can upgrade through a CHRA replacement path rather than starting over with a completely new system. Same turbine wheel. Same turbine housings.
New compressor wheel with the same compressor wheel contour. Same compressor housings.
Developed to Expand the Capability of the G-Series Platform
G-Series II was developed to give builders greater performance while maintaining the durability and reliability that performance applications demand.
As modern performance builds continue to push higher horsepower levels, builders need turbochargers that can deliver more airflow while maintaining efficiency across demanding operating conditions.
Garrett engineers focused on expanding the performance capability of the G-Series platform through improvements in compressor aerodynamics and flow performance, allowing the next generation of builds to take advantage of greater airflow potential.
At the same time, the platform was designed to maintain compatibility with many existing installation configurations, giving current G-Series users a practical upgrade path while supporting new high performance builds across a wide range of applications.
Compare G-Series II Models
Use this chart to compare horsepower capability, engine displacement range, wheel sizing, turbine housing options, and key configuration differences across the G-Series II lineup.
| G-Series II Product Features |
G25-585
|
G25-700
|
G30-725
|
G30-825
|
G35-990
|
G40-1000
|
G40-1250
|
G42-1325
|
G42-1585
|
G45-1610
|
|---|---|---|---|---|---|---|---|---|---|---|
| Turbo Reference Model | 4849 | 5449 | 5455 | 5855 | 6262 | 6270 | 7170 | 7375 | 7975 | 7982 |
| Horsepower Rating (BHP) | 585 | 700 | 725 | 825 | 990 | 1000 | 1250 | 1325 | 1585 | 1610 |
| Displacement Range (L) | 1.0 – 3.0 | 2.0 – 3.5 | 2.0 – 5.5 | 2.0 – 6.0 | 2.0 – 7.0 | 2.0 – 8.0 | ||||
| Compressor Wheel Inducer (MM) | 48 | 54 | 54 | 58 | 62 | 62 | 71 | 73 | 79 | 79 |
| Turbine Wheel Exducer (MM) | 49 | 55 | 62 | 70 | 75 | 82 | ||||
| T25 Inlet Turbine Housing (A/R) | 0.49 | X | X | X | X | X | ||||
| T3 Inlet Turbine Housing (A/R) | X | 0.83 | 1.01 | 0.83 | 1.01 | X | X | X | ||||
| T4 Divided Inlet Turbine Housing (A/R) | X | 1.06 | 1.06 | 0.85 | 0.95 | 1.06 | 1.19 | 1.01 | 1.15 | 1.28 | 1.01 | 1.15 | 1.28 | 1.44 | ||||
| V-Band Inlet Turbine Housing (A/R) | 0.72 | 0.92 | 0.61 | 0.83 | 1.01 | 1.21 | 0.61 | 0.83 | 1.01 | 1.21 | 0.85 | 0.95 | 1.06 | 1.19 | 1.01 | 1.15 | 1.28 | 1.01 | 1.15 | 1.28 | 1.44 | ||||
| Standard Rotation | Y | Y | Y | Y | Y | Y | ||||
| Reverse Rotation | Y | Y | Y | X | X | X | ||||
| Internally Wastegated | Y | Y | Y | X | X | X | ||||
Note: Scroll horizontally on smaller screens to compare all models. Use this chart as a starting point before reviewing the individual product pages for full specifications, turbine housing options, and application details.
Legend: Y = Available X = Not Available
Why Chris Forsberg Swapped from a G30-660 to a G-Series II G25-700
In professional drifting, the best turbo choice is not always the biggest frame size. Chris Forsberg’s move to a smaller G-Series II frame shows how improved response, controllable torque, and usable power delivery can matter more than simply chasing a higher theoretical top-end ceiling.
Going Down a Frame Size to Go Faster
Chris Forsberg and his team downsized from a pair of Garrett G30-660 54mm turbochargers to a pair of Garrett G-Series II G25-700 54mm turbochargers on his Formula Drift Nissan Z. On paper, stepping down from a G30 frame to a G25 frame may sound like giving up performance. In practice, it was a move focused on improving how the power arrives.
In drifting, immediate throttle response, boost recovery after lifts, and controllable torque during transitions can be more valuable than maximizing peak airflow at the very top of the rev range. That is exactly where G-Series II changes the equation.
With updated compressor aerodynamics, increased airflow capability, and improved efficiency, the G-Series II G25-700 helped support a result of 940 wheel horsepower while still prioritizing response and driveability.
Why This Matters
Forsberg’s setup highlights one of the biggest advantages of G-Series II: it can change how builders think about frame size selection. Instead of defaulting to a larger frame for peak power alone, newer compressor technology can allow a smaller frame to deliver the response characteristics a motorsport application needs while still supporting serious power.
In drifting, where throttle modulation, transition behavior, and boost recovery are critical, that can make a smaller G-Series II turbocharger the smarter competitive choice.
Continue Exploring Garrett G-Series II
Whether you’re selecting a turbocharger for a new build or upgrading an existing combination, explore the resources below to continue your G-Series II journey.
Browse G-Series II Models
Explore the full lineup of G-Series II turbochargers and review detailed specifications for each model.
Find a Distributor
Locate an authorized Garrett distributor for product availability, support, and ordering information.
Learn More
Download guides, explore technical resources, and learn more about Garrett performance turbocharger technology.
