I've been running 27psi daily. If you do some search on the Evo's 4G63 block you'll notice it's good to about ~500whp before things start taking a turn for the worse. The only thing I've ever worried about is the headstuds lifting...which the stock turbo will never flow enough air under any circumstances to cause. Hence why I'm going ARP with the bigger turbo
Oh and I love you. To complete the thought

__________________
JDM AWD Turbocharged Madness
The "replacement for displacement" is measured in 'psi'!
"You can lose a lot of money chasing women. But you'll never lose a woman chasing money." -A man much wiser than I