I have no doubts that the Salt Jr. F1D can win the world championship. It has been designed to be sturdy and simple to build. I believe it is a platform that can take you as far as you want.
As far as I can tell, no F1D design has an efficiency advantage over another design. Does Lutz Schramm’s beautiful high-tech F1D use less cruise power than Jim Richmond’s conventional Salty Dog? I don’t know, but I haven’t seen any evidence. Does the 5-inch separation between the wing and stab of Ivan Treger’s F1D mean that its stab sees better air than on Larry Cailliau’s F1D with a 2.2″ separation? I don’t know, but I haven’t seen any evidence.
However, one feature has been shown to be more efficient. The spar less propeller is about 3% more efficient than a conventional sparred propeller. I have measured the difference in my garage “lab” and flying the prop in the gym.
When you have wrung out 90% of the maximum possible performance out of your F1D, then you may be ready to tackle this 3%. At the start, you will do okay to reach 75% performance. When you reach 85%, you will have done really well and might win the junior world championship.
You should think of your F1D like a set of golf clubs. If you don’t have the skills, it doesn’t matter how high tech or expensive your clubs are. It is the magician that makes magic, not the wand. It is YOU who must make your F1D perform and dance. It is the skills that you bring to a contest that matter most.
Of course, you must have good clubs that are accurately made and won’t break during competition. Your model must be well built and sturdy. But this is just the starting point.
A contest is won by the flier who best pushes the limits of rubber and trim in the time allotted. Time and energy are in short supply at a contest, so a contest model must be reliable and low maintenance. Every repair and flying problem is a deterrent to a high place finish. A contest is often won by the flier who encounters the least number of problems.
During the 2014 F1D World Championship, my F1D was reliable and consistent. I encountered problems, but they were few enough that I could overcome them without much difficulty. The model didn’t have a perfect launch, and during the first circle, it did not climb as steeply as some of the other models. It did what was most important: It climbed all the way to the ceiling, and its launch was trouble free. Its consistency allowed me to place my efforts on pushing the limits of trim and rubber. I was able to trim it with a very efficient cruise and descent, and I spent most of my energy on choosing the right rubber cross section and winding the motor hard.