Grille shutters are no issue actually. The Active Grille Shutters (AGS) do assist with air flow and turbulence and only "shut" when constant cruising speed is detected (little to no throttle). Shutters open immediately, and often stay open after the car is idling or has warmed up to operating temperature. There is a sensor reading in the PCM system stating the AGS status. Under WOT, or sitting idle...they stay open and the "fins" make for better air flow. Anytime I wanted to WOT from idle, they were fully open so I can rule them out as being problematic. I only seen them completely close when using cruise control while on the highway. Stop n' go low speed traffic, they frequently adjust partially.
The real culprit is the poor aluminum quality of the Intercooler itself. It's just terrible at heat convection as it "grips" onto heat more strongly compared to higher quality variants. I don't even think an Intercooler spray bar would help much either, as under WOT all that exhaust air from the turbochargers just gets ignored from any cooling. Nearly hit 200 F at one time on a real long road pull at night time. The 3.0T makes better power at half throttle than full, having me suspect the turbochargers are too powerful (which ironically is a good thing) for the intake system at hand. This is why we get "effortless performance" without mashing the pedal, whereas the ECU manages the engine and turbos from getting too out of control.
Levels Performance made a great Intercooler for the Fusions (have one my 2014) and its the most important bolt on upgrade there is. C-PE's version is better for allowing one to retain the ACC and AGS systems, yet deliver equal performance. C-PE I know plans to provide a market for the Fusion Sport which is good news for us 3.0T owners with tunes. I'll definitely buy C-PE bolt-on Intake, Intercooler, Charge Pipes, Downpipes, and Exhaust if they come into fruition.
Edited by Zalvern, 20 March 2017 - 01:13 PM.