Bicooler with Air Conditioning On

Background:

This post discusses evaluating temperature from the bicooler with air conditioning on.

Several weeks ago a comparison was made of a front-mounted intercooler and stock location intercooler when the GTI air conditioning system is running. The intercooler outlet air temperature in the cold side charge pipe was compared between the two during a ~30-minute drive that simulated stop-and-go driving.

This comparison raised a question about how a bicooler with air conditioning on would perform under similar operating conditions. This post discusses the investigation that was conducted and the outcome.

Test Procedure:

The GTI is equipped with a Majesty front-mounted intercooler and a do88 stock location intercooler with the two connected in a bicooler configuration.

The remainder of the setup, route and operating speeds are the same as was described in the prior test.

Test Results:

The intercooler outlet temperate, intake air temperature, and operating speed are shown for the drive in the chart below.

The next chart shows a histogram of the IC outlet temperature over ambient during this drive. The bins are the temperature delta in degrees F.

The next three charts compare all three intercooler configurations; FMIC only, SMIC only, and Bicooler.

This chart shows the IC Outlet air temperature over ambient over the drive route.

The IC Outlet temperature over ambient data is summarized with a bar chart showing the percent of data points in each of the 5 degrees Fahrenheit bins:

The data points are further combined into box plots:

This chart shows the bicooler temperature delta minus the FMIC temperature delta throughout the drive:

Conclusions:

The addition of the FMIC to the stock location intercooler results in a slight increase to the outlet air temperature as compared to the stock location intercooler alone. The average difference over this test route is 3 degF.

The difference between the average temperature from the FMIC to the Bicooler is 13 degF.

As the last chart illustrates, the Bicooler minus FMIC temperature difference varies by approximately 5 to 15 degF after the mid-point of the drive. This is where the peak speeds increase to around 45 mph, as shown in the first chart.

Overall the results with the air conditioner operating are not surprising. The stand-alone FMIC has the lowest average outlet temperature. The stock location intercooler has slightly higher outlet temperatures, and the FMIC along with the stock location IC has the highest outlet temperature.