my csl is overheating

[7.77]

nothing really wrong, except when hardly used on trackdays.

in normal use,there is a little variation in temp: usually the needle of the gauge goes before (when decelerate) the temp logo then it goes a little after when i accelerate.

Yesterday, i was in the track of LA FERTE GAUCHER ( bad track), and the temp was getting hotter and hotter.......limit to the red

if i drive carefully (7000 or 7500 r/mn) the needle is on the 2nd point of the gauge.....and during braking, it cool down rapidly. But when i drive hardly (8000) the needle just doesn't stop to climb the temp gauge

My fan (in front of the watercooler) is running ok (but i don't really know if the speed is correct), and the other (the one in front of the engine) is okay. 30/45 minuts after shuting down the engine, when i start the engine, the temp is still in the middle of the gauge and the fan is still running.

The oil temp is always ok (about 120° when i drive hardly) and never goes higher.

please help me.....thermostat ??? temp sender ?? myself ???? french weather ?????