Let me share a few findings about this whole fan control idea.
The original plan was obvious enough: make an app, spin the radiator fan, cool the engine faster. I figured it would be a handy trick for dropping temperatures before a slalom run, or helping out after a track session.
Well, testing showed otherwise. Running the fan while parked does basically nothing for the coolant temperature. But strangely enough, it drops the oil temp quite well. If you think about the GRY cooling system, it makes total sense. The oil heat exchanger gets fed with the coolant coming from the radiator.
There is a catch, though. The fan also blasts that hot air straight into the intake manifold and bakes the MAP/IAT sensor, heatsoaking it nicely.
So what is it actually good for? Opening the hood in the paddock after a run and letting it spin. It doesn't replace a proper cooldown lap, but it helps drop the oil temp for the next session faster if you don't fancy installing a proper oil cooler. Add the classic "AC off, cabin heater on max, doors open" for even better effect.
