I logged a WOT run in Versatuner. At high rpm and high load, I have my open loop lambda set to roughly 0.8 in this area of the graph. The actual lambda logged is quite close to what I expect, within about 3%. However, it shows the desired lambda from around 5,000 rpm up to be 0.995. I know there are other things that factor into desired lambda like ECT, etc., but I can't imagine why it would turn my 0.8 lambda into 0.995 at WOT and 8,000 rpm. That seems rather dangerous. I'm content to leave it like it is until I get an explanation. Any ideas why it's doing this?

 

I see the same thing in Mazdaedit when logging "desired AFR". My only conclusion is that this value is not correct for open loop operation. Perhaps it should actually be called "desired CL AFR".

 

if it was as easy as just plugging in a known number and getting that as an output then there would be no need for people making their living tuning cars ...

 

So I guess it's not specific to Versatuner at least.

Well when you plug in a certain number for desired AFR, you damn well expect it to show up in the desired AFR PID in the log. I'm guessing you misread my post and thought I said the actual AFR doesn't match the desired AFR.

 

yeah, must have since I don't have ME