Not sure if this helps, but i'm finishing off a 60 sized slingshot at the moment (Was a very similar to the Lotus V, but designed and flown by David McFarlane from Wollongong). I've put the YS110S in it and am about to test fly. I've been told that the YS91AC used to give the plane more than enough power (Was designed originally for the OS61 Hanno) so the YS110S should give it plenty (YS110FZ is the same size at the YS91AC, the YS110S is only about a 1 millimetre taller and the most powerfull).

Will see how the plane balances out, I think the engine is around 730grams