Overheating? Thermostat?

[Freebaggin]

Since having prog ECU (for over two years now) with digital water readout, I have been able to monitor exact water temp. I have R33 with of course RB25DET.

The thermostat setpoint has is 82°C. However whenever I either drive up hills or use some boost (still light load stuff) it will rise to 86°C pretty quickly.

If I give it max throttle for a while it will rise to 90°C very quickly and at track days at Mallala it will reach 98°C after "only" 3 laps.

I have completely stock water cooling except for now an N1 water pump that is apparently much better for cavitation (or lack of) but even with this mod the temp goes up, but it is better. Also no oil cooling. Having said that, the Nissan dash water temp guage still reads OK even at 98°C.

Another thing, I live in a foothills location and the drive to the city is mostly very very slight downhill. It takes ~20minutes to reach operating temp in the morning. Whereas my wife's 2001 VW Passat takes a very very short time to reach op temp under the same conditions.

Is my temp hike I get a problem or just normal?

Is the slow warm up time normal?

Is the problem maybe an old/sticky thermostat? Or something else?

[4door_Sleeper]

Get a known acurate temp gauge and check your values.

20 min to reac opperating temp is too long, so something is wrong (the guage or thermostat)

Do you have access to an hand held digital thermomiter (laser sighted infa-red i believe) as these are very accurate and can read the temp of various points of the engine

Another possible cause(s) are:

faulty thermostat

blocked radiator

coolent problem

scale/etc in the block