Cylinder UV distortion Both cylinders have almost the same topology, and are unwrapped the same way, the distorted one has longer polygons. I tried different approaches but could only make it better by inserting a loop. Is there a better way to solve this?
This was an answer I got in polycount: Select the offending face and Ctrl+T. Once it is broken down into triangles Shift+right-click neighbouring PAIRS then Ctrl+J to join them together into a Quad. You might have a few stray triangles (which is ok), but unwrapping should then work as expected.
What does he mean by ''Ctrl+J to join them together into quads''? in the blender manual to convert tris to quads the keyboard shortcut is Alt-J, and Ctrl+J is to join objects, I'm confused.
Fbx:https://mega.nz/#!l3hy1KIS!6OViRzkx-...ByL8zZ2BKDwsLk
If you're simply trying to resolve the unwrap distortion, I'd verify that you have no doubles causing un-seamed edges that might be causing the warping.   This can be resolved without touching the object itself, which is what the polycount answer was pertaining to.


check seams 
U -unwrap mesh 
bring up the UV editor in a separate panel


You should then be able to manipulate the UV as you like.