With the GT you will not lower the peak temperatures by turning the fans on earlier or longer for that matter.
This car is different. The problem is heat soak under the hood resulting from poor air circulation from the engine bay. Turning the fans on early or for loner will only lower the temperature on a temporary basis. It will do nothing for the peak temperatures!
I’ve been there already. I’ve already gone to the track, walked out with a cold engine, run around 70 mph at the slowest part of the track. This is pushing much more air across the radiators than those two fans ever could. Still the temperatures just climb and climb / up to 235 getting close to 240 before I decide to end the session. Same exact experience stuck in traffic or driving slow around town on a hot summer day!
If anyone has empirical data to show that turning the fans on earlier or for longer time eliminates the climbing temperatures on the GT while driving slowly around town / stuck in traffic on the highway on a hot (90 plus) summer day / or for that matter driving the car hard at WOT conditions at the track on a cool 75 or 80 deg. for 20 plus minutes at a clip lets hear it. Who out there can report back they are running with the fans coming on early in their GT and they no longer observe the heat soak issue, climbing temperatures, the very high peak temperatures on the track.
In two weeks my car will be at Ida Automotive
www.idaautomotive.com / getting rid of the muffler and having his exhaust installed. Several here have already reported it works with peak temperatures reduced by 20 deg. This is real significant. Just do it or enjoy watching your temperature gauge climb when driving slow or at the track with the knowledge that your engine temperature truly is 240.
If you still want a custom tune Bob Ida can offer this too but if you just go with his exhaust you are not adding a “chip / aftermarket box” to the stock computer, you retain the stock cats, the sound level is very reasonable so you pass emissions without a hitch and the full Ford warrantee remains in tact.
Looking forward to 220 peak temps.
PS: This post is not negative about any one or any vendor on this forum.