PUMP
05-01-2006, 09:38 PM
I have reached the conclusion that a wide band (UEGO) sensor based AFR is required to properly tune a Lightning. I have done a fairly exhaustive search on all the various forums, and have yet to see anything concerning Right and Left sensors. The L's have four narrow band O2 sensors. Two (1-left & 1-right) for the closed loop control of fuel banks 1 and 2. There are also two (1-left & 1-right) next to each of the cats. The latter two have something to do with catalytic converter function.
Anyway, first question is: if the L needs wide band sensor, doesn't it need two of them? Especially if reason for the AFR monitor is to assure that we do not go into lean operation.
Second question: Does anyone have experience with the Innovate Motorsports LM-1 or LC-1 lambda sensors? These use the Bosch UEGO sensor and has two output serial signals, one of which can be used to simulate the OEM narrow band (0 to 1 volt) signal to the ECM. The second signal can go to a AFR meter, or as 0 to 5 volt input to the Xcal2. That way you can get true wide band AFR while using the OEM bungs. This is a plus because lnstalling an additional bung befor the cats looks to be difficult at best.
Third question: Getting AFR from dyno run, appears to have some accuracy problems. If you have the OEM catalytic converter in place, and the Dyno AFR comes from a sensor installed in the tail pipe (down stream of the cats), the AFR reading is probably going to read erroneosly towards lean since the the catalytic converter will scavange excess oxygene. So if you map the ECM based upon the erroneus reading you will end up running pig rich. This may explain why it takes several tune-dyno-tune cycles to get it right.
While browsing on this subject, I came across this little pearl of wisdom attributed to Arthur C. Clarke “any sufficiently advanced technology is indistinguishable from magic.”
Comments please on these questions.:eek2:
Anyway, first question is: if the L needs wide band sensor, doesn't it need two of them? Especially if reason for the AFR monitor is to assure that we do not go into lean operation.
Second question: Does anyone have experience with the Innovate Motorsports LM-1 or LC-1 lambda sensors? These use the Bosch UEGO sensor and has two output serial signals, one of which can be used to simulate the OEM narrow band (0 to 1 volt) signal to the ECM. The second signal can go to a AFR meter, or as 0 to 5 volt input to the Xcal2. That way you can get true wide band AFR while using the OEM bungs. This is a plus because lnstalling an additional bung befor the cats looks to be difficult at best.
Third question: Getting AFR from dyno run, appears to have some accuracy problems. If you have the OEM catalytic converter in place, and the Dyno AFR comes from a sensor installed in the tail pipe (down stream of the cats), the AFR reading is probably going to read erroneosly towards lean since the the catalytic converter will scavange excess oxygene. So if you map the ECM based upon the erroneus reading you will end up running pig rich. This may explain why it takes several tune-dyno-tune cycles to get it right.
While browsing on this subject, I came across this little pearl of wisdom attributed to Arthur C. Clarke “any sufficiently advanced technology is indistinguishable from magic.”
Comments please on these questions.:eek2: