Flying Hog,
I have the same plane GP Giles 202 1/4 scale. I was able to do the wall without snapping when I had it set too tail heavy, I was balancing at 7-3/4. I just changed my CG to 7-3/16 and haven't tested it yet. Also I think the weight of the plane may have some effect to this manuever. Mine weights 11.6lbs.

F16FxR4real,
The way to do the wall is to fly level at about 1/3 speed or less depending on engine, then immediately pull the elevator on high rates and the plane should transition to a vertical position and it stops flying forward just like it hit a wall. Then it's up to you after that, you can hover, torque roll or just full throttle up.