If the time for filing a notice of appeal has passed, has the superior court lost jurisdiction to grant relief?

I'm pretty sure you are not asking about a statute of limitations, which is when a complaint must be filed, but rather when a request for post judgment relief must be made. However, there is insufficient information to provide you with a response. What type of case are you referring to? Civil or criminal? Small claims? What kind of relief are you seeking? Amending a judgment? Vacating a judgment?

Most post-judgment bases for relief (motion to vacate judgment, motion for judgment notwithstanding the verdict, and motion for new trial) have time constraints after which the court is unable to modify the judgment. All of these time frames are well within the time to file a notice of appeal, so if the time to file a notice of appeal has passed, it is unlikely that anything could be modified. There are exceptions, for example for void judgments and default judgments in certain situations. Everybody needs to be certain of finality. That is why judgments become final and cannot be modified. That is the purpose of the time requirements for post-judgment motions and notices of appeal. As Attorney Chen pointed out--this is a completely different issue than statutes of limitation, which is the time within which a claim may be filed.