Using some basic math and estimations...The total height is 235 feet, forget the tunnel. Therefore we know from pictures that the max height of the second hill is just slightly less than 235', factor in friction etc, I'm assuming 30 or so feet shorter then the original 235 feet. Now we got about 205 feet. From Pictures we can tell there is about a 10' decline in the turn around, although the drop and banking is consistent, its hard to tell where the "turn-around" ends and the drop begins. Factor in the 3 feet or so of footings at the bottom, I would guess 180-190 is a solid estimation.
I think the turnaround is more like...part of the drop. Even then it's not minus 10 feet to the hill, the height of the hill is its height. Thats what I want lol. So more in the range 199-203 feet?