last years comp was based on Le Mans
I think it was guess the total race distance as the decider, like you i looked up the previous years distance and made an educated guess which was miles out.
Rain, june, at Oulton Park probably, they'll may use the island circuit like last years race, its on the same weekend as le mans.
so 1.20's
fosters circuit 1 min
international 1.35 - 1.45