In the debate between using a stock location intercooler or a front mounted intercooler a benefit for each has been claimed related initial cooling. Initial cooling for purposes of this post is how quickly the intake air temperature drops once the vehicle starts moving after being stationary for a period of time.
The claim for stock mount superiority in this capacity is attributed to a larger surface area and claimed greater cooling efficiency.
The argument for the superiority of the front mount is due to the direct access to the “fresh” air flow.
I haven’t seen this debate accompanied by any data, and since I have logged both types of intercoolers on my GTI I decided to review some data and see what it shows.
The data used in this comparison was recorded over a planned route that included several stops where the car was stationary and idling for one minute. After the minute passed the vehicle resumed travelling along the route.
The purpose for having a planned route was to try and control the vehicle speed and time at specific speeds, so that the route could be repeated with the second product under similar conditions.
Days were chosen when the outside air temperature was similar, although not exactly the same. A comparison of outside air temperature recorded by the vehicle temperature sensor along with the vehicle speeds are shown on this chart:
The intake air temperature would be recorded throughout the drive. The intake air temperature was normalized by subtracting the outside air temperature to produce a temperature delta along the route.
The following chart shows the temperature delta for the stock location and front location intercoolers.
Note: A constant value was added to the front location IC temperature to create an offset so that the data would be easier to interpret. The magnitude of the values of the front location IC temperature delta is raised for illustration purposes.
From the appearance of the lines on the chart I do not see an indication that one location is quicker to cool the intake air temperature than the other. Both locations show a rate of temperature drop that look similar.
It is possible that if the temperature drop times and degrees for several moments of cooling were more rigorously analyzed that a difference might be determined. Because these temperature drops are happening over a period of time that is less than ten seconds I’m not concerned with trying to determine if one produces a temperature drop a couple of seconds faster than the other.
Intake air temperature drop using a stock location and front location intercooler were compared to determine if one produced a faster temperature drop than the other. For the products used in this comparison, under the conditions describe above, no significant difference was recorded.