An 80" extra is gonna weigh at least 13-14 pounds minimum. No way a 150 saito is gonna be a good 3-D with that. If you want 80" and true unlimited 3-D then your gonna need a 40-50cc gas engine is my guess.

Even the ARF Extras that are 74" are minimally 3-D with the saito 150. Good aerobatics but defentliy not unlimited 3-D in that size.