Background:
The Garrett Powermax turbocharger for the Mk7 GTI features a customized turbo inlet elbow specifically designed to work with the turbocharger, but it is not interchangeable with the GTI’s stock IHI turbocharger.
This makes comparing it with the majority of inlet elbows something like comparing apples and oranges, but since I had the elbow, I tested it.
The Garrett TIP has an inlet sized to fit with the stock accordion hose, and an outlet that is 56 mm, inline with larger hybrid turbochargers.
Test Process:
Due to the Garrett having a different means of attaching to the turbocharger, an adapter was designed to join it with the flow bench, accommodating the difference.
The stock GTI accordion hose is attached to the TIP, and then the top half of the stock airbox is attached to the accordion hose to help smooth airflow into the accordion.
The flow bench is operated at a depression of 28″ of H2O, and the airflow rate through the intake parts is recorded.
Test Results:
The Garret Powermax Stage 1 turbo inlet elbow flows 470 CFM @ 28″ of H2O. This is illustrated in comparison to some IHI turbo elbows in the chart below.
Note: The IHI elbows are attached to the flow bench using an adapter that is larger than the IHI turbo inlet, allowing a more equivalent comparison. This is still not a direct comparison, and when examining the hybrid inlet elbow testing (not shown), the Garrett is on the lower end. That result is not unexpected given that the Garrett fits the stock accordion, where many hybrid elbows attach to larger, custom inlet hoses.
Conclusions:
The Garrett Powermax turbocharger inlet elbow was flow tested and found to flow 470 CFM @ 28″ of H2O when using a turbocharger adapter sized like the Garrett turbo compressor inlet.