sleeper7

Dataloged a 4wire heated Honda and a PLX 0-5 volt out w/b O2's. The Greddy E-O1 logs every 10th of a second. The N/B heated O2 voltage range the Greddy would log was from .70 to 1 volt. The Greddy was set to read the PLX voltage from 0 to 6.5 to get a smother line. The photo clearly shows the narrow band O2 follows the PLX voltage reading when the motor went rich or lean. In the photo the bottom line is the PLX and top is the heated O2. When the PLX voltage reads a higher voltage (lean) the heated O2 voltage falls at the same rate/as fast. I think the W/B make me lazy diagnosing a miss fire problem. With the N/B I had to think if it was a rich or lean miss fire where the W/B says rich or lean. The N/B voltage just goes to zero on all miss fires because it only judges AFR by the amount of oxygen in the exhaust. Rich or lean miss fires have lots of oxygen. But in my opinion as long as the motor is running fairly good the AFR's can be monitored with an N/B O2 with confidence. Most rotary motor will idle around 12.00AFR's. If the N/B voltage reads a given number for idle then under low boost numbers the N/B voltage should be no less then .05 to.07 volts more. My N/B voltage at idle is .83 while the PLX shows a 12.1afr. When the PLX shows a afr in the low 11's the n/b voltage is in the .92 or range. Every N/B O2 will read differently from each other but only by tenths of a volt. Is what I did once was put the car on a dyno and monitored the dyno AFR's and compared them to my egt number and N/B voltage. Tuned my motor to run some good numbers at the track like this. I also have been looking at N/B voltage reading for a very long time using a O-scope, that helped allot. Just thought I would throw this out there to stir up some controversy. Link below shows the datalog.

chuck

http://groups.msn.com/ChucksRX7/1987turboi...oto&PhotoID=552

j9fd3s

what happens when you get the narrow band hot?

sleeper7

I've had this same narrow Band O2 sensor in my down pipe, three inches from my turbo for a very long time. I try very hard not to let the sensor get over 1600f. I can show you datalogs of the N/B sensor during a 1/4 mile run. Steady as a rock. does not fall of at the top. I have read that a N/B sensor will read a lower voltage as the EGT number increase. I also read that their limits is 1600f. I am only putting this out there because I hear so much about the N/B sensor only able to read extreme lean and rich conditions and bounce up and down between the two.



http://groups.msn.com/ChucksRX7/1983rx7.ms...oto&PhotoID=553



Here is a photo of a 1/4 mile run. Bottom line is a heated O2 sensor, top line is my boost, 3bar map. Over 4 volts of boost.

chuck

j9fd3s

hmm insteresting