Investigating if the air scoop has a measurable affect on the conditions entering the GTI intake is something I’ve been doing preliminary work towards.
A temperature probe has been mounted at the outlet of the stock airbox to help test for changes in air temperature entering the system.
Installed into the top of the grill is the Eventuri scoop with a home made border.
The car is now equipped to record ambient air temperature, air temperature exiting the airbox, air temperature exiting the turbocharger, air temperature exiting the intercoolers, and air temperature inside the intake manifold.
As the chart above illustrates via the arrows, air as it travels along the intake path undergoes some significant temperature changes. It also makes evident the futility of trying to assess a part that is changed prior to the airbox, green line, by looking at the IAT, red line.