The Garrett CHRA for the G-Series II G42-1325 is the core rotating assembly built for enthusiasts and shops upgrading from Gen I G-Series turbochargers who want more flow without replacing their existing housings. Engineered with new compressor aero technology, this CHRA is the direct path to unlocking additional performance from a proven platform. It’s the ideal choice for builders who already own Gen I compressor and turbine housings and want to step up to Gen II internals.

Specifications

• Model: G-Series II G42-1325
• Garrett P/N: 938338-5002S
• Turbine Wheel Material: Mar-M alloy
• Turbine Wheel Temperature Rating: Up to 1050° C
• Turbine Housing Material: Stainless steel
• Turbine Housing Temperature Rating: Up to 1050° C
• Compressor Flow Improvement: Up to 10% higher compressor flow compared to G-Series Gen I at peak pressure ratio and peak turbo RPM
• Rotation Configurations: Standard and reverse rotation available
• Compatible Speed Sensor Kit P/N: ATP-ACS-032

Performance & Application

This CHRA is designed to deliver increased efficiency at high flow rates, giving Gen I G-Series owners a meaningful horsepower upgrade path while reusing their existing Gen I compressor and turbine housings. Calibration is required to fully realize the increased flow potential and take advantage of the resulting horsepower gains. Available in both standard and reverse rotation configurations, it’s suited for builders who want to extract more performance from their current G-Series setup without a full housing swap. This is a direct upgrade solution offered as a complete turbo unit, a supercore, or as a standalone CHRA purchase.

Frequently Asked Questions

How much more compressor flow does the G-Series II offer compared to Gen I?

The G-Series II delivers up to 10% higher compressor flow compared to G-Series Gen I at peak pressure ratio and peak turbo RPM.

What turbine wheel material does the G42-1325 CHRA use, and what temperature can it handle?

It uses a Mar-M alloy turbine wheel rated up to 1050° C, paired with stainless steel turbine housings also rated up to 1050° C.

Can I upgrade my existing Gen I G-Series turbo with this CHRA?

Yes, this is a direct upgrade path for

Downloads

• Garrett-G-Series-II-Product Flyer G40 42 45