Think you my ne forced to cut it mate, I have the big grs and its been a major ballache.
Temps shot up rediculously, then intercooler moved somehow, and hit the rear of the fan. The fan then burnt itself out!!
tried using an additive, made bugger all difference. The samco split on the turbo water feed too due to too much pressure when i boiled the water. Then changed the thermostat to a 82 degree item replaced all the samcos and fitted a new pacet club rad fan.
Chucked some water wetter in for good measure too and only used de ionised water lol.
Has only just bought the temps back down to where they were prior, i havent checked temp switch yet, forgot to check that, but it does make a difference mate