How safe is 10psi ?

[dudemaaan]

The stock ecu runs really rich, so even with the upgraded turbos you should be fine. Narrow band sensors/gauges don't really have the resolution to be much help. And the voltage isn't linear outside of stoich. Basically they just aren't accurate. But at least you aren't seeing yellow or red.

Since you aren't running much boost you can run fairly lean without trouble. Probably around 12:1. I doubt the stock ecu would be running any leaner then that even with the extra airflow. But you're still just guessing and hoping it isn't. You could always take it to a dyno and get a single run with the wideband hooked up just to know where you're at.

Or you can get a wideband controller and gauge and check it yourself. Eventually you will need to get a pfc and a wideband would very helpful. If you plan on making any real power with the BNR's you'll need this stuff anyways.