Background:
The Mabotech stock location intercooler for the Mk7 was previously measured for airflow using a flow bench.
Another consideration when selecting an intercooler is how well it cools and obtaining cooling data is the subject of this post. This test is to evaluate the air temperatures exiting the Mabotech stock location intercooler when operated under street conditions.
Test Procedure:
For this test the GTI is operating with a 93-octane tune from EQT with a boost profile shown below.
The GTI is accelerated at full throttle while in third gear starting from approximately 2,000 RPM and concluding at approximately 6,300 RPM.
The Intake Air Temperature (IAT) sensor reading when the engine RPM is 6,000 is compared to the ambient air temperature and the difference is calculated to determine the IAT delta. This IAT delta is the metric used for comparing with other intercoolers.
The GTI is driven briefly out of boost before repeating the process. This is performed a number of times.
An overview of a data collection session is shown next:
Note: IC_Out (orange line) is the temperature of the air exiting the intercooler which is different from the intake air temperature (IAT – red line). A separate temperature sensor is installed in the cold side charge pipe to record the air temperature before it enters the intake manifold.
The next chart shows a close-up of the segment of the drive where full-throttle acceleration took place:
Note: The IAT and IC_Out temperature are only similar during the full-throttle pulls. This indicates that the IAT sensor is an unreliable source of intercooler cooling performance when the car is operating out of boost.
Five test sessions were conducted.
Test Results:
The first chart series shows the IAT delta versus the time into the test session after the first pull occurs. Four test sessions are shown on these charts:
The next chart shows the average air temperature out of the intercooler minus the outside air temperature ten seconds after a pull concludes:
The next chart shows the IAT delta measurements for all of the stock location intercoolers that have been measured. Each dot represents an IAT delta value. Equal values form a horizontal line:
The final chart shows a composite of the flow bench recorded measurements versus the IAT delta for all of the intercoolers that have been tested.
The numbers after the product name indicate the number of data points used to calculate the average temperature delta and the number of sessions that were conducted to record the data.
The colored point is an average of the individual data points that are shown on the Dot Plot above. This chart also includes front mount intercoolers.
Conclusions:
The Mabotech stock location intercooler for the Mk7 GTI is the subject of street data collection.
On average the IAT delta during a pull is approximately 16 degF. The temperature out of the intercooler ten seconds after a pull averages approximately 14.8 degF above the ambient air temperature.
Cooling performance from the Mabotech stock location intercooler is similar to other stock location aftermarket intercoolers that have been tested using the procedures described above.
Note: The hardware, software, and operating conditions for this test will factor in the output temperature from the intercooler. This test does not necessarily indicate how efficiently this intercooler would operate with different components or under different conditions.