Hi Peter, the open pit lane day ( 9.30 - 4.45 ) was £109 and i am still on the original Bridgestones so maybe i was lucky that it was a hot dry day, having said that my oil temps were reaching 125 degrees by the end of each session and i had almost lost all clutch pressure by the end of the day ( it came back when the fluid cooled ).
You have got me thinking for another time kev. Would like to have at least one go.
I had all my fluids changed for decent stuff when the S/C was fitted so dont know if that will make a difference!
I don't have your normal overheating problems.
Glad you enjoyed it:)