Part 3 of testing variations on closed and open intakes is a test of a closed housing filter-on-a-stick. This is the MST Performance intake setup that MST donated to conduct testing with and includes the MST turbo inlet elbow.
With the cover in place the intake is “semi-closed” because there are areas of the air filter enclosure that can permit engine compartment air into the air filter.
The procedure followed with the MST intake in this configuration is similar to the previous test and consists of making a pair of third gear pulls with full boost to measure the air temperature entering the turbocharger.
Interestingly with the air filter enclosure covered the air temperature entering the turbocharger remains nearly constant during both of the test runs, illustrated by the green lines on the chart.