Often times you’ll hear or read in car and car part reviews how much of a problem heat soak can be for turbo cars, expecially modern ones with small turbos, double expecially if the car has a top mounted intercooler!

In order to study the validity of such claims, you’d need to collect some real world data from a car instrumented to record post intercooler temperatures over time while the vehicle is being used in a manner such that it would produce a great deal of heat.

Well as it turns out I tool my 2015 WRX to a track day this past weekend and it happens to have an Accessport which is capable of datalogging ECU parameters and an engine that utilizes a manifold air temperature sensor (intake temperature manifold) in addition to a pre-turbo inlet air temperature sensor.

The above plot is what that looks like on the latter 700 second half of a 20 minute track session. The red line is ITM, it does of course oscillate with boost pressure, but never does go over 126 degrees. Sure we’d love to have that a whole lot closer to ambient, which can roughly be approximated as 82 degrees, from the intake air temperatures, but at no point during 11 minutes and 40 seconds of track track use does it spiral out of control, lead to massive power loss and engine death...

Any questions?