Quote from JJ72 :

right, how can I cool it? mine keeps getting very very hot!!

You cool it by driving Much like in real life. If you rev the engine while standing still the temperature will rise very quickly. If you end up in a sand trap you're likely to fry your engine if you try to get out of it and don't keep an eye on the temperature gauges.

In the HistorX mod you can choose your radiator size for some cars, for example in setups where your engine tends to get too hot. This isn't possible in the Supra mod, though. If you just race on the track it should never get so hot that it damages the engine.

I haven't had real heat problems, but when I spectate online, most drivers seem to take corners one gear lower than I do, thus spend more time up in the rev range.

Have you ever got the 'oi temperature warning' symbol?

Quote from Niels Heusinkveld :

Have you ever got the 'oi temperature warning' symbol?

Only once, when I was trapped in a sand box and trying to get out. I haven't had any problems racing, the longest race being 20 minutes.