Sat here watching torrential rain obliterate the the view and thought I would offer a couple of suggestions..........
Road Ontario is good, mostly sweeping corners but a couple of bends that focus the attention.
Mid Ohio is similar in many ways.
Bluemountain is great fun with a few blind crests that will be exciting in the 65's but might prove terminal in a 67
Lime Rock ( not the "mountain" version as that has a bug) always generated great racing, a bit like Goodwood. Simple, but a challenge to get dead right.
Charterhall Airfield where Jim Clark started his career gave us some great dices in 65's a few years ago.
If you want some slipstreaming fun in 65's try Cilce, some long straights and a series of tight bends at one end of the track.
LOLOL the rain has just got so heavy that we cannot see the sea and it is only 50yds away!!!!.....just off to get my snorkel and flippers ready
Westwood is also good and we used it several years ago (I think Top Gear went there on one of their American adventures) should be a blast in 65's. Plenty of run off room...the only problem is that being a desert circuit the run off is sand...................
It pays to stay on the grey bits!.
