wideband lambda parameters

allm0t0rGSR · Post by **allm0t0rGSR** » Mon Mar 15, 2010 4:10 am

does the the ECU and lambda meter supposed to have the same voltage? and air fuel ratio value?

mine has to add 0.1 voltage offset to have the same air fuel ratio value on the smanage(Lambda Voltage 1.37v) and on the lambada meter (Analog2 input voltage 1.47v).

Post by **Spunkster** » Mon Mar 15, 2010 9:48 am

They may be slightly different, that is why we have the voltage offset field.

allm0t0rGSR · Post by **allm0t0rGSR** » Mon Mar 15, 2010 11:55 am

ok thanks....

but if i take out the 0.1 voltage offset they have the same voltage; analog input 2(b6) and lambada voltage but the afr value on the meter and on the sensor is off lil bit....

fly_n · Post by **fly_n** » Mon Mar 15, 2010 1:33 pm

'Lambda voltage' is the input voltage(Analog2 in your case) with the offset applied,thats why it is exactly different to your input voltage by the amount u enter at the offset input field.
If u enter 1V at the offset field u will see 1V diff between An2 & Lvolt...

allm0t0rGSR · Post by **allm0t0rGSR** » Mon Mar 15, 2010 4:21 pm

ok but are they supposed to have the same volts the An2 & Lvolt...

fly_n · Post by **fly_n** » Mon Mar 15, 2010 5:04 pm

Thats what im saying, Lvolt & An2 will only be the same when offset = 0V.

If u adjust the offset then that very adjustment will be reflected in the difference between the 2 values.

Lvolt is just a means of determining the relationship between what voltage is being used to determine your AF/lambda value conversions & the voltage that your wideband controller is spitting out.

Use Lvolt compared to (WB output V) or simply the AF/lambda values on gauge compared to logs to make sure your wideband & the ECU agree on what AF/lambda values u are working with at least on that front....

allm0t0rGSR · Post by **allm0t0rGSR** » Mon Mar 15, 2010 6:49 pm

i still dont get it?

1. Do the An2 & Lvolt have the same volts? yes or no

or

2. just -/+ v. on the offset field until i reach my wideband meter afr value have the same afr value on the smanager?

thanks

fly_n · Post by **fly_n** » Mon Mar 15, 2010 7:07 pm

Ok,do this,

Go to your car & put an offset of +1V in sManager & upload the cal,now start a datalog & bring up Lvolt & An2 on the same graph.

Notice how the Lvolt is following the An2 voltage signal graph,but it floats exactly 1V above the An2 graph?

Now put offset at -1V,upload,datalog.....

Now notice how Lvolt is following An2 again but its exactly 1V less than An2 voltage?

Put offset = 0V,now notice how Lvolt & An2 follow each other exactly?

Lvolt just equals WB input voltage (at the ECU) + offset voltage......
Simple as that.....

Get the picture?

For your second question,yes that is the alternative method other than comparing the voltages & is what most people do just match their gauge Af readings to the datalog AF readings.

allm0t0rGSR · Post by **allm0t0rGSR** » Mon Mar 15, 2010 8:55 pm

thanks alot for yur patient and help....