I have just removed the davis craig temp sensor that fitted in the top hose and fitted a switch instead that has an 92/87 temp range. During my track excursions though the fan I felt was allowing the car to go past this point, before the temp would come down.
Is it worth fitting a lower operating switch 88/79? I have a 14inch fan on the rad so this can ceratinly bring the temp down if required.
The car is an everyday car with occasional track use. What temp ranges do people out there have to operate their fans?

the fan shouldn't be doing much at the track, it should be working while driving in traffic at low speeds, maybe you need a radiator upgrade or renew