My engine is bone stock.
I monitor temps and pressures.
I run the biggest fucking oil cooler ever paired with this engine.
I have a diverter valve so I can control flow anywhere between full bypass to full cooler.
I only run 0w20.
Anywhere above 200 F the oil will not reach spec pressure.
If the engine is run steadily above 4500-5000, the oil gets hot quickly regardless of water temp. I don't know if all engines do this but this one is the first to which I've paid close attention. Based on my observations from tinkering with my system in all kinds of conditions, I can confirm the recommendations published by Setrab
here.
I run a little under half my oil through the cooler with a 180F thermostat in all cases except sustained operation between 5000-redline. Then, my 72-row, series-1 just manages to keep the oil below 190F.
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tl:dr
Unless it's a dedicated track car, pick a cooler designed to dissipate around 30KBTU/hr. You won't be sorry.