The topic is a good question, and I know the answer has been covered, becasue it varies from one engine to another, and one driver to another.. But generally it is 260-275.. That said I have 3 different engines and every one of them keeps a different temp..
In My truggy I have the Sirio/ExTech .24, and it is crazy powerful at a max of 210. I've seen another leaned out to get it to 235 and it was ballistic..
In my Buggy I ran a Sirio EVO IV, very similar to the Extech, but it like 230-240 best.
IN my T-Maxx I have a Picco .26 Max.. It like 280 or above.. I bough tit used from a guy I race with. He said don't worry about temps that engine will handle it.. He oval raced that engine, before I got it.. He had seen 350 from it before. The week after I bought it I was running it through some tall grass at WOT, and came in and it temped at 395. I fueled it putted arounda bit and it dropped down to abbout 310, and has run fine ever since..
So like said tune to performance and smoke and you won't have any problems..