I am trying to max out a few suits of armor beyond legendary and I need to know how much does your smithing skill have to be boosted beyond 100 to get to the maximum level cap. I have noticed that some people have armor sets that have armor ratings up to 1000. How much skill do I need to do that?
In a previous answer, I boosted my smithing skill from 100 to 130 by using two +15 items.
This was sufficient to get to the armor cap (567 rating) with many armor perks in Elven armor. Rating higher than 567 yields no additional protection.
If you're smithing something with higher base armor rating (which most armor has), it would take less smithing skill.