Drilling thermostat

[Halon]

AS OF 8-23-07
New Mishimoto all aluminum radiator
2 fans wired always on
160* thermostat, holes drilled, and now just completely removed
different coolant mixtures, and redline water wetter
new oem mitsu headgasket
new coolant line and clamp
new gaskets
new rad cap
vented hood
new water pump (better design then what was in there) and o-ring
burped numerous times




OK in my never ending quest to figure out what in the heck is going on with my car, I'm back to the thermostat again. My car runs hot mainly when driving on the freeways. Hot as in the needle starts to move past straight up and down and I get scared and stop. If I crank the heater, this helps quite a bit, but it sucks driving everywhere with the heater blasting.

So I've been reading up about how people drill little holes in their t-stat. Now I'm staring at mine, and the only spot there's any room to drill, is the big ring around the edge. But I don't see what that would do, that's not the part that moves up and down. Plus there's already a large opening in the top, where the rod connects to. Anyone able to clear this up for me at all?

BTW, car is a 91 tsi. Thermostat is a 160* one from AZ.

Other things I'm doing right now is replacing all the coolant. Going to go with a new mix of maybe like 65water/35antifreeze. Also dumping a bottle of water wetter in. It doesn't appear that I'm losing coolant, but sometimes I think I can smell some. But everytime I pop off the cap, it's full to the top, and the overflow doesn't seem to be budging at all.