APR Intake Airflow Test

Some previous testing looked at the stock Mk7 GTI air intake to evaluate how much air flows through the system with a couple of simple modifications as well as when configured as delivered from the factory.

This test is being conducted to determine how much air flows through the APR Carbon Fiber Intake for the Mk7 GTI.

The Setup:

Similar to the previous tests, the testing of the APR Intake is being conducted using a flow bench which means that any potential benefits derived from the Carbon Fiber material on Intake Air Temperature are outside of the scope of this test.

The APR replacement carbon fiber intake pipe is connected via a straight adapter to the flow bench.

The flowbench is adjusted so that the pressure drop across the air intake system is equal to 28″ of H2O and then the airflow at that depression is recorded.

The Results:

The APR Carbon Fiber Intake flowed similar to the different configurations of the stock airbox.

The manufacturer, APR, provides airflow results on their product page.  They provide test results at a maximum depression of 24″ of H2O.  At that pressure the APR results show an airflow of approximately 468 CFM.  If the results are scaled up to a test depression of 28″ of H2O the airflow is approximately 505 CFM which correlates well with the 501 CFM reading that was obtained with the direct 28″ of H2O reading made during this test.

The results that APR found for the stock airbox show an airflow of approximately 440 CFM at 24″ of H20.  Once again scaling this up to 28″ of H20, the result would be an airflow rate of 475 CFM.  When I measured the completely stock setup airbox at 28″ of H20 the result was a value of 486 CFM.  While this result is slightly higher, it is still reasonably close.

Conclusion:

The results of an air flow test of the APR Carbon Fiber Intake for the Mk7 GTI on a flow bench correlate well with the findings reported by the manufacturer.

Results show that the APR Intake increases airflow to the engine when compared to a completely stock configured Mk7 GTI intake.

An easy modifications to the Mk7 GTI intake is the removal of the grate from the lower half of the airbox.  Making this changes results in the stock airbox allowing airflow that is equal to that of the APR Intake.

Replacing the stock Mk7 GTI air filter with an aFe Power fabric filter allows the stock airbox airflow to modestly exceed that produced by the APR intake.  It should be pointed out that if the stock airbox is installed in the engine compartment of the Mk7 GTI there are other components that could potentially cause a different outcome.

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Update:

On June 15, 2019 I ran this flow test again, this time using an adapter that has been made to simulate the intake to the turbocharger compressor housing on the IS20 and IS38 turbochargers.

For the update I decided to record the test and present the results in a YouTube video.

The comparison airflow results between the APR Intake and APR Turbo Inlet Pipe and the stock Mk7 GTI Airbox and Turbo Inlet Pipe are shown again on the chart below:

As previous tests of the various turbo inlet elbows have shown, addition of the inlet elbow to any air intake system produces a significant drop in airflow through the intake system.  As a result the relative differences become smaller, though the relative ranking remains the same.