Working version of the phenomenon known as the Cyclotron. This version does not rely on accidentally shooting through a tube wall, but gives you a choice: Take the exit, or go through the loop.
Note: There’s no way to tell if it will prioritize the loop or the exit. Depending on what behaviour it takes on, you may have to hold down a key to choose the loop, or hold a key to exit. The default behaviour may switch once, after that it’ll remain as is. The actual entrance and actual exit can be placed anywhere, but from experience the cyclotron itself needs to be placed on the ground, otherwise it will slow you down midloop for some reason.
Happy travels!