A lot of variables here.
For most skiers not at 28 off at 34-36 mph - take the wing off. It is a brake. You are not generating enough speed to need it.
If you really want to get into it: www.carbonfins.com
Here is the typical ski set up instructions:
1. Set the bindings to factory spec.
2. Set the fin to factory spec.
3. Adjust bindings first.
4. Fin depth is the most critical - set that first. Use .002" increments.
5. Fin length is next, move in .002 increments.
6. Distance from tail is next, move in .002 increments.
7. Set wing angle in 1 degree increments.
8. Take your time. This typically takes a few weeks to do right unless you have a lot of experience.
As for your question, you are probably breaking forward at the waist, that is a technique problem, not typically a ski set up problem, unless the ski is too short for you and is stopping in the turn. At the www.carbonfins.com
website, look for the "basic relaxed position" and videotape yourself and see how you compare. Your shoulders should be back, chest out, arms low and on the vest, butt cheeks tight, hips forward, knees slightly bent. Your posture should be a "strong tower." firstname.lastname@example.org