It's a trolley, so it probably won't make the totally sick loopety loop, especially with all that meat on the track. It'll be too slow, and not awesome at all. So switch the trolley out with an awesome rollercoaster car and attach rockets to it.
There is basically no way to do that loop anyways. You'd have to already be moving freakishly fast, and have some hella sharp wheels to lower drag caused by slicing through victims as much as possible, and even then you probably wouldnt have enough momentum.
And if you were going that fast, you wouldnt have time to switch tracks if you wanted to.
*driver* BUT I WANNA DO THE LOOPDALOOP!
And if you were going that fast, you wouldnt have time to switch tracks if you wanted to.