this isn't really a problem with the panel, but an aircraft.cfg problem and should be taken up with the model builder. However I may be able to help.
Open the aircraft.cfg file using notepad and scroll down to the [contact_points] section, the first point in the listing (point.0) is usually the nosewheel, go to the 8th parameter ( this is the max steering angle in degrees) and increase this by 5 or 10 degrees at a time until you find an angle that suits you. Don't forget that slowing down a little before making a turn helps a lot.