winreboot,
What you are doing is TOTALLY useless... there is virtually nothing you will discern from a stock O2 sensor. You see a lot of these gauges and such for a/f and it is likely the biggest scam going. How a stock O2 sensors works is the following: when a/f is below 14.7:1 there is one voltage and when above 14.7:1 there is a higher voltage. Your stock ECU, similar to ECUs in other cars, simply uses the stock O2 to "hunt in" on the desired (ideal) a/f which is 14.7:1. In other words, there is really no way, for example, that these O2's can tell the difference between 10.0:1 and 14.0:1.
If you are trying to use the stock O2 for tuning forced induction motor, you likely want to target an ideal (under bosst) a/f of 12.5:1. If you are running under 11:1 you're too rich and if you get North of 13:1 you may be in trouble. The stock O2 or even the available aftermarket gauges CANNOT discern the difference.
The good news (sort of) is that there is a solution. In fact it is a very good one, albeit expensive. I am using it now to tune my BBSC. The kit consists of a 5-wire (expensive) O2 sensor and a black-box brain/controller. Once installed, it will let you display instantaneous a/f ratios (accurate to 1/100) and, more importantly, it will let you datalog for virtually any period of time. You can then playback the datalog or, using the supplied software, you can generate a/f graphs. There is a provision for a RPM-in (mandatory) and an auxilary in (0-5v) for a Map-in voltage, for example.
All values are datalogged.
My testing has consisted of modifying the fuel maps and then doing 4 or 5 2000-6000 full-throttle acceleration runs. (6K-8k can be tuned in after you get the hang of it.) I use 3rd gear and will use 4th gear for final tuning. It is almost essential to have a passenger with you. Have the passenger watch instantaneous a/f to make sure no values over 13:1... while datalogging the whole sequence. Next, return home and view the graphs. Make changes to the table and repeat the process.
If you are careful and methodical, I believe that this method with the right tools is the BEST way to tune a forced induction car like the BBSC. In my mind, many advantages over the Dyno.
I hope I haven't over-reacted to your O2 question, but please be careful regarding the expectations you may have on what the stock O2 can do for you.
