It flies perfectly fine on a .91 / Dynamax. The stock exhaust liner doesn't really work with the Dynamax, I used the rear section and for the front section I modified the front section of ducting from a Yellow F-4 - it mates wit hthe fan unmodified but needs to be overlapped and shrunk at the rear to mate with the kits rear duct section.

Make sure you add the fences on the wing! With those it is basically un-tipstallable. Mine flies off grass with cutouts in the rear fuse side to allow TRIPLE the stock throw values and when I rotate off grass I've got full up-stab. No tipsall problems at all, it likes to drop the left wing a bit as it comes off but it is easily corrected with aileron and it flies away.

I have some packing under the fan ears to center my fan a bit, I use the JMP pipe system. You want the header they sell for the F-18 which has a 6 degree angle machined on the face.