I wouldnt hit the pipe at 90degrees for a few reasons. Its just harder for one, turning in the air, shootin straight up, its not easy. What you need to do is find a good angle to go at, somewhere in between 45 and 90, especially when your learning.
'Computer games don't affect kids; I mean if Pac-Man affected us as kids, we'd all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music.' -Kristian Wilson, Nintendo, Inc, 1989