ORIGINAL: UNDATC
Hi all, I'm looking at upgrading to more power on my goldberg ult. bipe from the YS91AC to the YS120NC. I put in a smoke pump, tank, and battery and now it doesn't fly like it used to. Is the 120 the same physical size? And could I expect a moderate difference in performance?
If you move from the 91 to the 1.20 you will need to change the mount as the 1.20 is a larger engine and weighs more. It will certainly give you more performance but realize that you are going to increase your wing loading even more. With the addition of your smoke system you added weight and added to the wing loading, the 1.20 will just add more. A 1.10 weighs little more than the 91, drops into the same mount and makes almost as much power as the 1.20F. If you already have the NC then I can see using it but if you were looking for a replacement engine the 1.10 would be my choice.