Scott, you are correct in the judgement of exact location vs altitude. Lower is easier to judge how close to the pylon you are, and how well you are flying your line. But it doesn't make lower always the best choice, as staying low and eating dirty air from the plane(s) ahead is rougher and slower. And the fastest line isn't always the closest to every pylon, due to the geometry of the course, and depending on the speed of the aircraft. Axel called it a cone, or similarly, you can think of it as a cylinder over the barrel, like the light beam over the Luxor in Las Vegas. Put your wing into the beam, and its a cut, like AC said. How close you can judge your proximity to the barrel does change with speed and altitude. As you learn to fly the course, you learn where to put your airplane to fly the fastest line, and how close to the pylon you can get without it being a cut (you don't really know till you cut one). And a position error or turn error on one side of the course has an impact on the next few pylons, perhaps all the way to the other side of the course. Then throw a few other planes in the way, and its a very interesting and challenging environment.
With respect to radio calls: The racer being passed is not required to make the call "you're clear". So as the passing plane, you need to make the judgement when you are clear. We train to temper aggressiveness with caution...and self-preservation. Fortunately, it's rarely a hard concept to teach! Safety first...come back to race another day!
Often the passes are silent. And there are stories where the racers attempting to pass said (for ex), "2-6, 8-7 on your right", and that's all 2-6 needed to hear to make an adjustment, plan a turn, etc, to stay ahead.
But we talk to each other as needed when it gets dynamic, such as approaching a tight turn and you see the guy behind and on your right coming up, but at your altitude, and you know you are about to go belly up to him (legal, because he still has the separation part of the contract as the passer). We may tell him we're going belly up, so he knows it's all on him for separation. Or say he's slightly in front but you have the inside line on the turn (the pass is not complete and he is not opening sufficiently)...we may say "2-6, hold your line", to let him know his nose to tail will not last, and it will not be safe to "close the door" and complete the pass.
Its not constant chatter, but timely calls when, and if, needed. The contest committee chairman complimented our class on our on-course communications. Something we are proud of, as it shows how good pilots, good procedures and good training can make a very dynamic environment a bit safer.
And FWIW, yes...it is very, very addicting!
So if you watched Axel's video, and if you looked at the passing section of the training doc...did you notice AC's nice positioning, lap after lap, while setting up his pass? Methinks he read, listened, and applied it all quite well in the arena, eh!
All the RV bubbas did a great job!!!
Cheers,
Bob
