Very interesting that the shop owner claims that he was able to reduce oil temps down to 240F. I wonder what is different about the cooling/airflow compared to this from the FK8 and FL5.

As it stands right now with the FL5 just an oil cooler and a radiator upgrade will alleviate cooling issues. For the FK8 you need 2 oil coolers + 2 Auxiliary radiators, to fix the cooling (this is a bit overkill for most but its needed for fast drivers. The owner of the FK8 with a bunch of records on the West Coast tracks just tried out a new radiator kit under development and had success. 0 cooldown laps for a 20minute HPDE session).

Seems like the GRC needs less engine cooling modifications that the CTR which is interesting.