After 2 years of doing more endurance focused work I have a good graph from Intervals.icu on power-vs-HR at relatively the same FTP:
That is % threshold HR (LTHR).
Previous seasons I did not have good data between 90-150W. What’s somewhat interesting is its basically a straight-line below FTP, which is what I’ve seen in several studies on PubMed.
That graph does require some context, as it can reflect the type of intervals you do, if you do some z1 work, etc., etc.
The “benches” at 83% and 85% and 88% LTHR are interesting, however I’m not sure if they reflect the work I’m doing or have some basis in physiology. I will say that 83% is where I detect a small change in breathing, during warmups. And that 88% is an average HR that I can sustain on harder 6-7 hour efforts without feeling crushed for days.