Toscana is your best bet for number of corners on tarmac, but I haven't heard of people getting more than eighty turns there. The highest numbers come from Liege, with figures of about a hundred at the top end. However, what this means is that all you have is a mindless series of twists, and while that may sound good it makes for a generic, soulless track. The longest Liege track I know of is one of mine at 7.54 miles, and I've had upwards of a hundred turns in tracks of seven or more miles, but that's a lot of corners crammed into a track that's just over half the length of the Nurburgring Nordschleife, and the turns on these Liege courses are generally sharp. The Ring is more than just a mindless series of sharp turns, with all the various turns and complexes having their own personalities, and there's plenty of opportunity for high speeds along the way around Nordschleife, versus twisty Liege tracks where it's just low-speed corners and nothing else.
A good track needs more than a relentless barrage of sharp corners. You simply cannot get courses of ten or more miles in Course Maker, let alone do so with a hundred or more turns and them not all be simply one hard, slow turn after another.
