The C of G is 4 1/4" to 4 3/4" back from LE. I ended up all the way to 4 3/4" But l would suggest the intial flight at 4 1/4" and work your way up.

Cheers

PS. Just to make sure you understand, l am talking about the thunder tiger arf/arc fun tiger. Hate to see you put this CofG on the wrong plane.