RE: Evening the field
We just went with the established time as described in the RCPro warbird rules since that was basically the size of plane we were already dealing with, although we don't require the planes to be warbirds just any plane with a minimum wing area, maximum weight and no bolt on wings and must be propeller driven with any power source. I should point out that we do have 2 classes that follow both the Bronze and Silver times, that helps to separate the pilots. We have flown this format at fields that were limited on space so we moved the pylons in to 600' and adjusted the times, (i.e., 600' is roughly 85% of the distance that 700' is so we adjusted the time accordingly. Instead of the breakout being 2:30 or 150 seconds we dropped it down to 130 seconds or 2:10).
As far as it favoring a "faster" plane, no not really. In all the racing I have done both locally in our events and in the RCPro Warbird series you find that there HAS to be a bit of strategy involved. I can cite a perfect example that happened to one of our flyers just last Saturday at the Warbird race in Tucson. He had a Bronze class plane that in all his practicing and flying it in competition, he knew for a fact that with the plane set-up as it was, if he got a perfect start and if he flew a perfect course it would fly just under 2:30. So, the plan was to be just a few seconds late on the start and fly per normal. The problem in Tucson that became evident about 3 heats in was that we discovered the day and weather couldn't have been more perfect for the performance. The air was very cool and VERY dry and there was no wind to really speak of so by following the plan, his plane actually ran about a 2:20. The guy that won the Silver class never ran any faster than a 2:14, (the breakout is 2:00), yet he won the class by nothing more than being consistent, not cutting out and assuring that he got a good start and finished every heat. These are not common examples but the point I am making is that by running this style of format, the races are much easier to manage and it rarely boils down to who has the fastest plane.