By loosening up the front limiter straps youll remove ski pressure from the front, this will make the sled hard to steer into corners, meaning:the skis wont bite in.
It will also make the sled do wheelies like your wanting, however one other thing is it will most likely rachet the track alot depending upon how far you let them out, because the front arm will extend out and less of the track will wrap around the drivers. When you punch the sled the front arm tries to push into theground, this pulls the track from the drivers so your touching less drive teeth on the track. Dont be suprised if it eats hyfax right at the curve very quickly also.
What you need to do is go out slowly andfind the setting that will aloow you to turnand give you a good bite on take off.