The hottest ambient temperature I have tracked my SS 1LE in was 98°F near the end of September 2019 at COTA during this session around 2:30pm with the sun beating down and the car was not bothered by the 273°F max oil temperature! I was using the Mobil 1 ESP 0W-40 oil though. 5W-30 oil may have thinned out too much at that temperature which is probably why it is not warranty approved for track use for the SS and SS 1LE.
And here are more detailed lap by lap temperatures from Harris Hill (a smaller track) last week around 6:30pm when it was 91°F and sunny outside. Ambient and car temperatures from Eagles Canyon Raceway the day before were similar.
To address the OP's original question, I have been fine with running oil temperatures higher than the 250°F mentioned in the first post for a cumulative total of a few hours each year over the last few years. Personally I would not try it without running 0W-40 Dexos 2 oil and I would not do it regularly. And with the LT1 trim it is probably wise to watch temperatures closely when driving on twisty roads due the the reduced cooling capacity compared to the SS and SS 1LE.
EDIT: There are a few ZL1 guys on here who have hit oil temps in the 290°F range on track without posting about having issues later on:
https://www.camaro6.com/forums/showt...1#post10821841
"Just as oxygen causes a cut apple to brown or exposed metal to rust, it breaks down base oils and reduces motor oil’s effectiveness. Oxidation can lead to increased oil viscosity, which negatively affects energy efficiency. It also causes the formation of harmful deposits and sludge.
...
The rate of oxidation for oil doubles for every 18°F increase in temperature."
https://www.amsoil.com/newsstand/mot...-deteriorates/
I also found this from 2005 but I imagine oil technology has improved since then:
"To begin with, we spoke to Quaker State engineer Mark Farner about what goes into this new generation of synthetic engine oils and what kind of advantages they promise. Synthetic engine oil has always enjoyed a reputation both for its high-pressure lubrication performance and also its ability to withstand much higher engine oil temperatures than conventional petroleum-based oil. Conventional oils will tolerate engine oil sump temperatures of up to 250 to as much as 275 degrees F without difficulty. According to Farner, oils like Quaker State's full synthetics can easily withstand sump temperatures in excess of 300 degrees F, and he says that some oval track race teams are experimenting with temperatures as high as 350 degrees F.
For a typical wet-sump engine, 300 degrees F is still extremely hot, but Farner says that synthetics, because of their molecular makeup, are better suited to withstand these temperatures.
The downside is that additive packages do tend to break down faster in high-temperature environments, so if you plan on running oil temperatures in excess of 300 degrees, this would mean changing the oil after every track event regardless of the mileage."
https://web.archive.org/web/20060627...116_0409_slip/
Blackstone Laboratories sells oil analysis kits and they can measure your remaining additives (TBN) for an extra $10 above the $30 base UOA price if you want to take a sample during your next oil change and send it in. "The lower the TBN reading, the less active additive the oil has left. A low TBN test result, meaning very little additive is left, is down around 1.0 or lower."
https://www.blackstone-labs.com/do-i-need-a-tbn/
Here is a street driving example of 4k miles with TBN at 5.9 even though the Camaro oil life monitor was showing only 2% oil life remaining:
https://www.camaro6.com/forums/showp...7&postcount=50
And here is 5k miles including 7 track days with TBN at 4.0 with Mobil 1 ESP 0W-40 oil:
https://www.camaro6.com/forums/showp...5&postcount=16