After seeing the substantial decrease in airflow through the intake with the addition of the stock Turbocharger Inlet Pipe the next logical question was how the results would go with the stock airbox in the stock configuration.
To recap the last test, it was conducted with the highest flowing configuration that the stock airbox has produced so far. The stock paper filter is replaced by an aFe Power dry fabric air filter and the grate located in the lower half of the airbox is removed. This configuration served as the baseline for the subsequent test that added the TIP to the intake.
With the substantial drop in airflow, even with the high flowing stock airbox configuration, the question became how much further would the airflow drop if the completely stock airbox and filter were used?
The stock intake along with stock Turbo Inlet Pipe is attached to the flowbench using a straight coupler hose and airflow at 28″ of depression is recorded.
Not surprisingly the airflow dropped in comparison to the aFe filter test. What is notable is the amount of the drop, only 8 CFM.
By comparison, without the TIP in place the difference in airflow between the stock airbox setup and the aFe filter setup, the best case arrangement, is 26 CFM.
The straight coupler that attaches the TIP to the flowbench is not quite a representation of the inlet to the turbocharger. A future investigation will involve making a 3D printed model of the compressor housing inlet to serve as the adapter to the flowbench.