Why Can the EJ20X Handle 14psi at 9.5:1?

A post on NASIOC talks about CR vs. boost explained (jump below for the important part).

Firstly in the post, it is stated that 12.67 is the max effective compression ratio (ECR) on pump gas. Second, there's also a table (see attached image) that shows that ~12 ECR is max on 92 octane pump gas. What puzzles me is, from my understanding, the EJ20X engines have a static compression ratio of 9.5:1 and are capable of handling 14 psi of boost from factory. According to the table in the attached image, that boost-CR combo has an ECR of 18.5.

How is that possible?

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The important part :D (link):

"Higher static compression creates more power throughout the rpm band, but it'll lower your maximum allowed boost before the onset of detonation. Boost is worth way more power than compression, because boost raises your compression and your total air flow at the same time. With the down side of, when you're not on the boost, you have slightly less power.

"Effective Compression Ratio = static compression ratio x (1 + boost/14.7)^1/2

"For a car running 8.5:1 pistons and 18psi(~max on pump gas)

8.5 x (1 + 18/14.7)^1/2 = 12.67 ECR

"If you run 9.0:1 pistons and want to maintain the same 12.67 ECR (~max on pump gas), you'll have to lower your boost to: 14.4psi

[(12.67/ 9.0)^2 - 1] x 14.7 = 14.4 psi

"So you have to run 3.6 psi less boost to maybe pick up a tinny bit of bottom end. Or to take it even further for 9.5:1 you can only run 11.4psi. I'll tell you right now that the difference between 11.4psi and 18psi is huge. And at some point (12.67:1 in this case) you can run no boost and be maxed out on ECR for pump gas. And how fast is a N/A car with 12.67:1 compression, ask the Honda boys running 15's.

"Of course you get to a point where you don't want to go the other way too much ether. A 6.0:1 car isn't too much fun on the street, but it can run 50.8 psi boost on pump gas. But the kind of turbo that could support that much boost would never spool up. You have to find what's right for you, but 8.5:1 is what most of the DSM guys like. My friend just built a motor for his DSM with 9.0:1 JE's and he is quite upset to find that he's getting lots of knock running 16psi. While lately in the cold weather, I've been running 20psi (8.5:1) on pump gas w/o any knock. And I drove his car and the difference in bottom end grunt isn't even noticeable. And his top end performance is sad compared to mine."

Well, they do eat themselves pretty often... I also find these hard rules are pretty bunk - there are so many factors that play into engine safety margins.

I might be wrong here. But my thought would be that when you increase compression ratio, eg via different pistons then this increases the heat simply by compressing the air more inside the cylinder. getting the cylinder conditions closer to the point at which detonation might occur. However when you increase the compression of the air before the cylinder in the turbo charger, that air first passes through an intercooler which removes a lot of the heat as a result of compressing that air. therefore so long as the intercooler can compensate for the increases in the charge air temp you can effectively have a higher amount of compression before reaching the point of detonation.

My personal view would be, i'd rather have the tunability of a turbo than fixing my compression mechanically via pistons. You can turn a turbo down, hard to do the same for pistons. eg if you are at the track and the intake temps are getting high, you can pull some boost and protect the engine.