Well, I should probably tweak that statement a bit. The Rotrex offers a few more variables to consider when planning boost. First the top end number is max boost at max rpm. It isn't sustained for very long and changing pulleys to lower the number reduces the entire boost curve. So you plan a little higher than the sweet spot of where you will spend most of your time and tune around the top end with spark and fuel to keep from detonating.

The numbers tend to throw people off a bit as it isn't the exact same conversation as running 13 psi with a turbo or twin screw.

But to answer your question, my current thinking is that 13 psi is the TOP end of where I want to be. It really all depends on how this car reacts with its inherent idiosyncrasies and where its sweet spot lies.

The great news here is that I have spark and fuel control via the AEM = ability to tune for boost. Unlike the "Base Kit" strategy that some employ to save cost and complexity by adding fuel via an RRFPR and low boost so they can run stock timing. In those setups, 13 psi would blow them sky high therefore the typical 8psi for stock compression you see as common.

I still wish I had a full ECU replacement but at least I get to use my cool "Auto Tuning" Spreadsheet to dial in fuel so I'm stoked!