-Try and get these on your first play through. This doesn't unlock just because you have the other three Speed Demon achievements unlocked, they need to all be done in one game.
- This works just like the Swan Diver achievements. You have to get them in one succession. If you don't get it, then reload the save "Southern Mexico Xibalba" and play until you finish the Valhalla maze. It will take about 45 minutes (skipping collectibles) to get to all three challenges and should unlock when you pass the two poles in the maze.
-Do the times quickly since there's no indication that you finished in the set time.
Note: Reloading the save on your first play through will save over the previous auto saves, so you'll have to grab all the collectibles again.