Sorry I didn't realize we were talking a 2010 Lambda set up. See if you can find the latest TTS tuning manual on the web, it is very detailed and has a lot of tips. They do a real good job of explaining the lambda protion of the AFR's. Ever since I did the latest download for the Screamin Eagle Race tuner the manual has disappeared from my desk top ?

 

Here is some reading that may be of some use.

http://www.megamanual.com/begintuning.htm
http://www.drdyno.com/

 

Difference between lambda and Afr is Afr is a calculated value based on reading of the voltage from the sensor. Lambda is the actual voltage reading and is more precise. A particular Afr has a range of o2 values that equal the target Afr. Manufacturers are switching to lambda values to allow more precise control for emissions purposes.

 

Kinda. The real reason, though, for the switch to lamba-based tuning is because the numbers are then independent of the fuel.

This didn't matter for a long time when all everyone used was gasoline. Then a lambda of 1.0 meant an AFR of 14.7:1 and that also meant stoic; it didn't change. O2 sensors read lambda and its then a one-shot calculation to get the AFR.

Now we have a range of fuels: gasoline, E5, E10, etc. Talking about AFR is not as useful as the tune varies depending on the fuel, stoic is different for gasoline and E10, for instance. Luckily though, lambda doesn't change with fuel. Lambda of 1.0 means stoic no matter what the fuel is and, as that is what the O2 sensors read, all is good no matter what you throw into the tank.

Which is, of course, one of the excellent reasons not to disable closed loop.

 

2 things...It may not be much, but help files say .976 to 1.000 is closed loop in lambda, which seem to give more of curve than 14.6
B. Has anyone discovered a way to print out the entire help file that now is imbedded in the overall tuner program?

 

Not sure what you are saying here. Do you mean its richer or that you can set closed-loop to a wider range of values or...?

 

I had a 2010 Fat Boy and used 14.6.
It seems that with lambda one has a little variety of what will be closed loop, so more range.

 

yes a tad richer and still closed loop O2 control
14.3 AFR or .976 lambda

 

and does anyone know if the maps on Super Tuner represent stage I unless otherwise marked?

 

in 2010 I spoke with the dealer dyno guy. Told him I just bought the SEPST and wondered if I should get the dealer stage 1 download. His words were if you have the SEPST software then you have the same map as the dealer download.