Question about AFR on e85
 

So I just flashed my car on e85/flexfuel with a jdl turbo. My afr sitting idle is ~16.2and my target afr is 16.03. I always thought that I was supposed to stay 14.7, is this an issue? I know that with ethanol, timing could be a little more advanced so that may be why my afr is sitting at 16.03-16.2 idle. Can anyone confirm this? I sent a log over to my tuner already since he wanted a cruising log but I wanted to ask the public as well.

Also gotta add, when I cruise it's around 15-16

are you reading that afr from a wideband or from obd lambda #1?

I thought e85 stoich was 9.8:1.

Obd

If it helps, I'm on OTS stage 2 e85 tune. My commanded AFR at idle is 14.94. Actual is around 14.6.

i gu3ss that 14.94 is at a cold engine idle. When warm the ecu CAN T target leaner than 14.7

even if e85 stoich is something around 10:1, the lambda sensor will always think in Petrol Afr. so it will target 14.7 even with ethanol

Hmm not sure what to tell you. Coolant temps are 195+, oil temps 200+, commanded AFR is 14.94 at idle.

Here's an example from a log:


https://datazap.me/u/darksunrise/e85...3149-3118-3100

you have Oft i guess.

well oft is bugged since always. the command afr log value has a strange lean offset, that 14.94 actually is 14.7 as you can see from your actual afr
so many years and Openflash never fixed it. i really personally hate that thing and tuning with tactrix is so much better and so much more values together

I have ecutek, if you were referring to me lol.

No sorry, was replying to DarkSunrise
ecutek always logs perfect and with fast refresh rate:) i log more than 60 values at the same time at 40Hz with ecutek, oft less than 12 values and not even 10Hz

The 02 sensor measures free oxygen, not afr. The 02 sensor is scaled to read petrol afr regardless of if car is running e85 or petrol you should see about 14.7 afr target and 14.7 commanded afr at idle once car warm.


Under light load 13 afr heavy richer like low12 or even high 11.


This is the reading you will see if logging using standard 02 regardless of petrol or e85 as the 02 is scaled for petrol afr readings.


The true e85 afr will not be shown

Something is up with your tune, E85 should read the same AF. All my readings stayed the same switching to E85.. You can run + .5 to 1 AF so up to 15.7 but it will down on power. I use this for my economy map. On your power map you will run about the same AF ratio as gas for max power. But you may be running more port injection ect so the AF ratio may change. Your Custom AF ratio map may not be working right....

whats the mpg before and after when putting around town?