Originally Posted by BrianBrave
...Prior to this mod, one of the biggest IAT issues I noticed was when; after driving and the engine a full operating temperature - I would stop and shut the SRT down (say to have lunch or dinner at a restaurant) and when I re-start the SRT - the IAT's had skyrocketed. I took this has heat soak cooking the IC with now coolant flowing in the IC or the HE - This problem is now almost gone - I think the heat wrap contributed to this but it may have also added to the other problem...
I believe what you are experiencing is due to the larger volume of liquid acting as a heat sink. It will take longer to heat up, but will also take longer to cool down.
I suggest additional means of extracting heat from the liquid should be employed, such as fans or a larger heat exchanger.
BTW, your insulation job will really help when you run ice in the reservoir by mitigating heat transfer from the motor.