What is the max safe cylinder head temps that you can run for an extended time - same 20 minutes? My 2016 GT motor is still stock without a tune or performance adders. Running at Willow Springs this past weekend I hit CHT's in the mid to upper 240's a couple of times. Not knowing the answer to this question, I immediately slowed down and within half a lap they were back down to the high 220's/low 230's where I put the hammer down again. I will be adding some Trackspec louvers in the near future to replace the stock ones. The idea is to enhance aero some, but mainly to improve cooling since I have a Ford Performance Power Pack 3 sitting in the garage waiting to be installed.