Now that I am running closed loop with pretty good results I am curious where my o2 upper & lower thresholds should be as well as the Mean R/L. Looking at the EBL Flash base bins I see some variance as well as seemingly backwards settings. Like a lower mean mV at higher MAP values.

I've read a lot of the info regarding the logistics of what these settings do. So believe I have a good understanding of their function. Just don't know exactly how to apply it. Especially knowing some of these settings are in relation to the function of the catalytic converters which I am not running. I run Premium E10 fuel, which is basically the only ethanol percentage available anymore unless you want to pay big money for "nonethanol rec fuel". So assuming a 14.2 AFR stoich value for E10 fuel, I have my closed loop commanded value at that. The o2 should match as well for 450mV being "stoich". Since the narrow band o2 finds stoich for whatever fuel it is burning.

To date I have been running these settings. Found in the EBL_F_PT4.bin file. For reference on my WB I was seeing a fairly steady average 15.2 at highway cruising and 14.2 at idle with these settings yesterday.


I am thinking these would be more in line with what I should be after? These are +-50 from the mean values. With low MAP starting at 450 and then working its way up. Cruising being slightly richer (plan to incorporate lean cruise). Then as non-PE load goes up work AFRs down. Am I thinking correctly here? I like the idle, so I haven't made adjustments there.

 

Word salad ahead as I think and type at the same time. I wanted to add to this because I had a light bulb moment on something I was chewing on in my head all morning. I mentioned the E10 fuel above and how I have the tune programmed to correlate to the stoich 14.2 AFR for that fuel. However I don't believe I have ever gone into the LC2 Programmer software and changed my 1.0 Lambda value from 14.7 to 14.2. Being a wideband controller that converts lambda to AFR, that means my wideband would be skewed slightly. If I was running a constant perfect 1.0 Lambda with narrow band reporting 450mV my ECM would think it was running at perfect 14.2 but my WB would be reporting 14.7.

This all perfectly correlates to the above values I was running. A mean R/L idle mV of 560mV would translate to a slightly richer than 1.0 lambda idle. The mean R/L mV of 425mV at cruise kPa of 45kPa would translate to a slightly lean from 1.0 lambda cruise. My datalog shows a average 14.2 idle and 15.2 cruise. Working backwards from that knowing my WB thinks 1.0 Lambda is 14.7 AFR, that means a reported 14.2 idle is indeed slightly richer than 14.7 (1.0 lambda) and similarly a 15.2 cruise is slightly leaner than 14.7 (1.0 lambda). Just like the mean mV targets. Honestly all this really means is it is working nicely in closed loop, even if the WB is slightly skewed. But for me what it means is a better grasp of why the WB was reporting what it was. Maybe this will help people down the line trying to grasp WB vs NB reporting and how 1.0 lambda vs various fuels stoich AFR can affect it.

I am still interested in comments on my first post about changing those o2 mV values.

 

I too questioned the $8D TPI R/L threshold tables as they have the values seemingly backwards... leaner at higher loads.

The DA2/DA3 reversed it... went richer at higher loads, and makes more intuitive sense.

I ended up following the DA2/DA3 example... my thresholds go up fairly linearly from 500mV at 20kPa up to 550 mV at 100 kPa. I used to have to it going from 600 to 750 in order to get my AFR's where I wanted them.

But after having converted over to the DA2/DA3 O2 proportional gains and delay factors (in my other thread about my overall conversion to DA2/DA3), I was actually able to lower the R/L thresholds by quite a bit and get the same result. Don't ask me what the mechanism is for that though as I have no idea... I'm just reacting to data. But the transition from non-PE to PE is also a bit more seamless too (via seat of the pants feel), which was an added benefit.

 

Yep, I posted the EBL values mentioned in your DA3 thread. I will eventually get to trying those out.

 

Verified that my stoich settings in LC2 controller were incorrectly set to 14.7. I did a custom fuel of 14.2 to account for the E10 fuel I run then updated EBL settings to match the voltage to AFR scale. Only thing I might not be able to fix will be the wideband gauge I am running. It is a cheapy EVO gauge from an old cheap WB kit I ran. It is setup to expect a 0V=10AFR and 5V=20AFR scale. However the new scale doesnt jive with that. I am going to rewire the gauge to my analog output 2 on the LC2 wideband and play around with its settings to see if I can get some kind of close match to the true AFR being reported to ECM. Worst case it is off a little and I use it for just visual quick referencing while driving

After making my changes I looked back at a datalog from last night my idle was actually at about 13.8 and my cruise was about 14.7. Glad I found that stoich mismatch as it appears that was my main issue. Those fit right in line with my slightly rich idle mV and slightly lean cruise kPa mV that it was running on. I will give the adjusted mV I showed above a shot the next time I drive it and go from there. I am sure I will have some VE changes to make with the adjusted mV settings. Then maybe try out the DA3 prop gain settings to see how they work with a long tube intake.

 

Was just thinking about this. Do you have PE come in sooner or later? My base setting PE Enable TPS is 40% to 60%. Not sure if I should bump that up in conjunction with the R/L thresholds being revised or not. With my VE table having come from a open loop tune I am finding I am rather rich when in PE. Which isn't too surprising, need to work on that area of VE table.

 

Mine is about the same on TPS.. 60% at lower TPS values going to 50% at higher ones.

DA3 has it coming in at 50 kPa, which is what I use too.