I’m reposting Ed Anderson’s workbook from a long time ago that may help set cooling system expectations. Some of the fields are password protected and duct airspeed is locked down at 30%. Hopefully Ed Anderson is still monitoring this thread and can share his expertise and password to allow modification to cell C2 on the Cooling Calculations worksheet. Even without changed cell C2 we should be able to estimate BTU rejection by calculating the duct airspeed percentage. At 10%, BTU rejections should about 1/3 of the calculated value at 30%. Also my 2.75” coolant cores preform about 35% better than calculated when comparing  air Delta T, fuel burn / HP.

Bobby