Gavin I would do my best to talk you out of it. If you do put a smoke system in it. Put all the smoke stuff on a plywood tray. Then fly it with and without the extra pound or so of weight. The difference will be a noticeable. I really think smoke is better for a larger plane. The ULT is a great flyer but if it dies with the smoke system in it. It will go in most of the time.

David