When I get around to running my .18, I'm going to start at 340mm per my documentation. I left the header a little long so I can pull the pipe out, or shorten it as needed. Based on the hot humid air we have here in Texas, I'll be sure to get the pipe right before I fly. I haven't weighed the DJ-1 yet, but it feels very light. I installed a Robart nose retract instead of the Pilot unit so I could have ground steering. Even with that gear and the two servos needed to make it function, I still needed to add 1 oz. to the nose to achive balance. I figure the retract takes the place of dead weight