For those of you with an aftermarket water temp gauge, what water temps do you usually see on the track (road course or autox) or during high-RPM, spirited drives? My temps tend to climb to around 210F on a 70-80F day after 5-10 minutes of hard driving in the mountains (stock cooling system, streetported S4 TII, stock boost).

Also, list relevant info such as ambient temp, radiator, water pump pulley (underdriven?), thermostat, ect.

 

210 isn't that bad for that kind of driving. I'll see around 91-95C or 195-203F if I am doing that kind of driving in the summer. S4 T2 with FMIC and Fluidyne radiator, A/C delete. The factory FD cooling fans don't even come on until 220. Not that that's a good thing, but it just shows that these motors can take more heat than you think. The thermostat doesn't even open completely until 95C/203F.