reccomended psi

[randomcaller]

Hi all at the moment I'm trying to keep with the safe 18 psi on my 205 xud. I've tuned the Lucas pump and adjusted the wastegate on the turbo and I see 16-17 in most gears peaking to 18 in fifth and fourth. I think more max fuel is needed still as she doesn't smoke at all and doesn't reach higher psi in the lower gears but there is less load on the engine. What psi would you say is best to run without putting too much risk on the dhy block? Is 18 a good number to aim for?

Thanks