Bolt this to the rear iron to stop the flywheel so you can turn that big pain in the @$$ nut. It bolts in two places so it wont turn on the bolt and lever the casting ear off the iron... Ask me how we discovered that.
I printed it in ABS, but it would probably work in any plastic. you want to print this with 6 or 8 perimeters on a 0.4mm nozzle. I used 4 perimeters on a 0.6mm nozzle. I used 40% grid infill as well. you want this to be hefty, the torque spec on that nut is like 350 foot pounds, so this thing is probably seeing around 600 pounds of force.
One of the legs has a cutout so that it will miss the alignment dowel its supposed to go around. This should fit turbo rx7 flywheels, as well as renesis flywheels.
Angry eyebrows go against the build plate. Why angry eyebrows? Because it looks like its chomping your flywheel :)