Boil potatoes and eggs and let cool Cook bacon and reserve 1 tsp of the bacon grease. Once bacon has cooled enough to handle crumble bacon. Dice and chop onions. In a large bowl add potatoes, eggs crumbled bacon, chopped onions and cheddar cheese. Add Hellmanns, sour cream, salt and pepper. Mix well, add bacon drippings and stir again. If salad is too dry, add more mayonnaise. Allow to chill for several hours or over night.