Glen- you need to keep your car and get it in the 12's before you worry about this stuff!
Anyway, 14.7:1 is stoichiometric. At WOT, most TR guys shoot for the low 11:1 range. From what I understand from bruce about the stock O2 sensor, its about as accurate as a rich/lean indicator and no more. Tuning with a stock (narrow-band) O2 sensor is a guessing game. This is where the wide-band O2 comes in.
Its very accurate to read your Air/Fuel ratio to make sure the car is tuned correctly. FAST systems come with a WB02 for fuel correction and precise tuning (ask the high rollers in chi-town like Tony or twin 93 svt
) who have a FAST. I cant afford the stuff they got. Thats why I will take a 'lil spot on the street for a few bills.
The new units that came out such as the one you mentioned are stand alone units. You can have your chip burner make changes to the chip's fuel curve based on your current and target Air/Fuel ratio.
Alot of people use a dyno to tune their car because most dynos have an air/fuel meter that they hook up to your exhaust. If you have your own air/fuel meter (a WB02), you can tune yourself.
Make sense?
-Filly
ps. About the heat deal. The Bosch O2 sensor is not very tolerant to heat. Turbo cars have high EGT's, thus heating the sensor much more than an N/A application. The sensor can not operate properly when their housing gets over a certain temp. Some have made a heatsink to dissipate the heat from the sensor housing, allowing the sensor to operate normally (and accurately).
