With regard to AFR/lamda/LC1 output voltages.

As I understand it the LC1 analogue output 2 will output 0.0 volt at 7.35 AFR and 5.0 volts at 22.39 AFR.


The standard MyECU map uses 8 flags:

  0.00V,-3.00V,-2.75V,-2.50V,-2.25V,-2.00V,-1.75V,-1.50V

I assume these equate to approx:

7.35 AFR, 16.5 AFR, 15.7 AFR, 15.0 AFR, 14.25 AFR, 13.5 AFR,  12.7 AFR,  12.0 AFR

(As close as I can get from drawing a graph!)

So which is flag 1 and which is flag 8 please?  i.e. does flag 2 = -3.00 v or -1.75

Do I need to reprogram the LC1 for these negative figures or should I just put a multimeter across the output and find out if mine is outputting positive or negative and set the map accordingly.

At the moment I am using the LC1 output 2 to drive an AFR meter, typically it shows 22.2 with the engine stopped and around 14.1 with it running on a fast idle.  I assume I will have to program the LC-1 to output 5v ( + or - ) before connecting it to the My15M. At the moment I have my map set to the Breva standard O2 sensor so perhaps I could leave the map alone for the moment.

Any advice other than which flag is which.

Many thanks for the reply.

I will do a few trips with the stock non-lamda ecu to see what kind of AFR figures the standard bike offers.  Then I will refit the My15M and do the same open loop. Hopefully that will allow me to see how close the two maps are and then try closed loop. Initially I will try to get the map to equate with the stock item.  I have a second hand Stucchi xover and a pair of used Mistral alloy silencers that I hope to play around with. As I understand things any mods designed to increase power should initially make the bike run weaker, any power gain coming from the fuel you add to get back to a correct AFR.  Be interesting to see if I am correct.

So the -ve sign indicates the slope is from high voltage to low, 5v being max weak at 22.39 AFR  and 0v being max rich at 7.35 AFR for the LC1.

Rick4 mentioned connecting the AFR meter in parallel with the MyECU,  I assumes this means to the same analogue output, is this a good idea as I suppose it would then display that which is actually being sent to the MyECU.