Garrett G25-660 Turbo Assembly w/Internal Wastegate (Standard Rotation) - AMS Performance (2024)

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The most powerfulsmall frame turbocharger on the market

Introducing performance out of a package you never thought possible. This clean sheet product is tailored to meet the demands of hard core racing enthusiasts while providing industry leading power capability in a small package.

The G-Series G25-650 turbochargers are compatible with 1.4L – 3.0L engine displacements and capable of producing up to 650 horsepower. G Series 25 turbochargers are smaller and outflow all comparable products on the market.

New compressor and turbine aero combined with high temperature resistant materials allowed engineers to push the limits of performance.

A new name designates a new generation of industry leading technology and innovation.

Understanding the Name:
G25-550 || G25-660

Gdesignates 81 years of Garrett® heritage.

25classifies the size of the frame. The remaining 3 digits identify themax horsepower rating of the turbocharger. (ie 650)

• G SERIES COMPRESSOR AERODYNAMICS FOR MAXIMUM HP

• 54mm TURBOCHARGER COMPRESSOR WHEEL

• 79% MAXIMUM COMPRESSOR EFFICIENCY

• MAR-M ALLOY TURBINE WHEEL RATED UP TO 1050° C

• NEW TURBINE AERO PROVIDES HIGHER FLOW AND EFFICIENCY

• STAINLESS STEEL TURBINE HOUSINGS RATED UP TO 1050° C

• OIL RESTRICTOR AND WATER FITTINGS INCLUDED

• FULLY MACHINED SPEED SENSOR AND PRESSURE PORTS

• TURBOCHARGER ASSEMBLIES ARE CALIBRATED WITH A 0.5 BAR ACTUATOR

• Read About Turbo System Optimization: A guide to setting up your turbocharger

WARNING: Maximum allowable turbocharger speed is 165krpm. 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.

Compressor Aero

Forged fully-machined compressor wheel and new aerodynamics increase maximum horsepower output and boost response. The CFD (computational fluid dynamics) engineered compressor wheel increases air flow up to 15% for 60mm and 30% for 67mm with 79-80% efficiency. (Compared to GTX GenII)

Available in standard rotation and reverse rotation options for enthusiasts that want the perfect twin turbo installation or a single reverse rotation turbo for applications with installation restrictions.

Center Housing

A new one-piece center housing and backplate increase durability and product safety by reducing the number of failure points associated with the turbocharger. The center housing to turbine housing v-band connection allows for 360 degree orientation when installing with Garrett® non-wastegated turbine housings.

Four large water jacket ports increase cooling capacity and allow enthusiasts to customize water line routing to help improve the installation process. The turbocharger comes with two -6AN water fittings and two plugs. *Recommended to install waterlines on opposite sides of the housing.

A single stage oil passage directs pressurized oil to the new oil cavity ensuring proper bearing lubrication at both sides of the cartridge.

Each turbocharger includes (1) -4AN oil restrictor fitting with a 1mm orifice to provide the turbo with the recommended 40psi of oil pressure.

Rotating Group- twin piston rings

A shorter bearing cartridge allows us to incorporate twin piston rings on both sides of the shaft wheel assembly. This will reduce the likeliness of oil leakage at the seals from the center housing to the compressor and or turbine stage.

Turbine Wheel Aero

The turbine wheel features all new aerodynamics to improve flow and boost response. The new turbine wheel is made of Mar-M super alloy and is capable of handling exhaust gas temperatures up to 1050 degrees C.
The new turbine wheel flows 15-20% more than GTX and has peak efficiency of 74%.

Turbine Housings

All G Series Turbine housings are made from stainless steel to provide ultimate durability and temperature resistance up 1050 degrees C.
Internally wastegated housings are compact, efficient, and designed with maximum bypass port size to reduce boost creep and provide better boost control.
Turbine housings are available in a variety of wastegated and non-wastegated, open volute, T25 and Vband configurations so be sure to order the correct part for your application. *IWG housings are sold assembled as a full turbocharger, while non-wastegated turbine housings are available separately from the SuperCore (CHRA+compressor cover)