11-12psi on a stock block Zetec is HIGH boost. It's almost more than you want to run. You need seriously good tuning and decent gas to run that much. Definitley can't run it without an intercooler.
Like I said timing is the key. Pull enough just before boost kicks in and add alittle back in the upper rpms to cool the EGTs and it should live. A good rule of thumb is half a degree per 10 hp up to 200whp then 1 degree for every 10hp after that.
A few Focus are running 200whp with stock timing and just a fifth injector/fuel cut defender setup, but some can't run 5psi with out knocking. Part of that may be some can use 93 octane and some only get 91. Big difference in octane between regular gas 87 and 93 octane here. If you can only get 91, you need more timing pull.
And if you try to experiment with adding back timing, do it in half degree increments. I speak from experience.
2000 Rio Red I4 Cougar
200whp & 210wtq at 9psi
254whp & 276wtq with NX 35shot
WRX TD04 Turbo, Cut Short Shifter, Strut Tower Bar, 17" ZN Wheels, Roush Springs, Starion Intercooler, NX 35 shot, HKS SS BOV, Full 3" exhaust,StreetFlight Chip
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