I have only a fellow flier that uses the big Super Tigres and he says FAI fuel only. 7D carbs are getting hard to find. I do not recommend Super Tigre for any 3D either. I do run them hard, but I do not have deadsticks or bad transitions. I run a 10X8 on a ST G.45 and it's running faster than my AX .46 with a 10X7 APC.