35oz on 170sq". But this was with 600W of power. 150MPH for 90 seconds, then it was a floater. I could land it at my feet everytime. Use a good airfoil. RG14 or 15. I've flow 16oz airplanes at 140sq" too. Back when Speed 400 was the craze there were pylon racers at 12oz on 80-90sq". These were tough to launch if you weren't good at it.

The thing to make sure is that your pitch speed is sigificantly higher than your stall speed, minimum 2:1 for an airplane that will be comfortable to fly.