DDFI-3 tuning with stock o2 sensor

[lowkey]

I reas somewhere that the midpoint on the o2 sensor is something very relevant. The stock calibration puts the mid point at 0.4885v and the tuner lowered it to 0.47v, which is the average of rich and lean voltages. But the point on doing this I dont know yet.

I was wrong before, the goal he was after was in fact to change the target AFR value. I do not yet understand what would be the difference of a short spread VS a wide spread if the midpoint is the same number.

It seems that changing values to shift mid point will change the sensors target AFR. With the modified midpoint value of .47 the target AFR is 15.1, remember the lower the midpoint value the leaner it will read.

Have a look at this chart
http://cherrypicker.tripod.com/id12.html

Using that chart, if we take the stock mid point of 0.4885v the target AFR is reading is 14.8.


You can see the richest value possible to be read by the narrow band is only 14.4 AFR, much to lean to tune WOT.

[d_adams]

Dang, I have 4.2 sensors

http://www.innovatemotorsports.com/support/49.php

The new dual wideband from innovate the dlg-1 uses 4.9 sensors. If I didn't already have what I have, I would get that

My question on this particular setup is, does it have only ONE narrow band simulated output or TWO? I almost bought this the other day but decided to do a little more research on them first. 10 phone calls to Innovate went completely unanswered on Friday at 3PM (one hour prior to their advertised closing) so I don't know what the output is. I need 2, otherwise it's wasting money.

[AZmidget91]

My question on this particular setup is, does it have only ONE narrow band simulated output or TWO? I almost bought this the other day but decided to do a little more research on them first. 10 phone calls to Innovate went completely unanswered on Friday at 3PM (one hour prior to their advertised closing) so I don't know what the output is. I need 2, otherwise it's wasting money.

Jacob has one. Apparently it is 3 outputs, a digital output for the wide bands, and 2 analog outputs which can simulate the narrowband.

[mcaff]

Jacob has one. Apparently it is 3 outputs, a digital output for the wide bands, and 2 analog outputs which can simulate the narrowband.

AZ from this can I assume I can buy one Innovate LC-2 kit plus one spare bosch 4.9 and make everything work together?

[mcaff]

I was wrong before, the goal he was after was in fact to change the target AFR value. I do not yet understand what would be the difference of a short spread VS a wide spread if the midpoint is the same number.

It seems that changing values to shift mid point will change the sensors target AFR. With the modified midpoint value of .47 the target AFR is 15.1, remember the lower the midpoint value the leaner it will read.

Have a look at this chart
http://cherrypicker.tripod.com/id12.html

Using that chart, if we take the stock mid point of 0.4885v the target AFR is reading is 14.8.


You can see the richest value possible to be read by the narrow band is only 14.4 AFR, much to lean to tune WOT.

I think I'm too stupid to understand the rational behind this. It doesnt make sense to me changing the midpoint voltage of the sensor. As per the graphic you posted, that would make mixture even leaner as 0.50v corresponds to 1 lambda factor.

[lowkey]

I think I'm too stupid to understand the rational behind this. It doesnt make sense to me changing the midpoint voltage of the sensor. As per the graphic you posted, that would make mixture even leaner as 0.50v corresponds to 1 lambda factor.

You are exactly right in your thinking! That is what I'm saying, if you want to bump the fuel up a bit go to a mid point of .5v or higher, this will also effect the open loop fuel bumping it richer across the map as well.

I still don't understand the thinking of what the tuner was trying to accomplish you referenced who changed the mid point to .47v

[mcaff]

Mcaff: Thanks My controller accepts 2 sensors and the single gauge has 2 displays.

AZ: I saw that thread a while ago, but didn't worry when Theoctopus replied:

"Looks like it [Innovate] would work fine.

The LC-1 [4.2 sensors] gets close enough for normal use, but it's up to you if you want to spend the extra money on a 4.9 controller."

Now I'm curious which O2 sensors I have! The kit is pretty new, I wonder if they changed what O2 sensors they supply since that thread is from 2011.

Would you mind sharing with us what controller you have? Actually I'd like to know everything you have in your setup as I am about to purchase one for my Uly. If possible I'd install two wideband sensors connected to one controller and from it to the ECM. If this setup gets too complicated I can just leave the stock NB in there to feed the ECM and use the WBs only for tuning.

[mcaff]

Found a good discussion around o2 voltage in here:

http://badweatherbikers.com/buell/me...tml?1218319578

[mcaff]

Posted by Gunter, one of the guys behind ECMSpy, in another forum:

QUOTE
From the Screamin Eagle manual "Closed Loop Bias adjusts the AFR control point from nominal. Note: Lower values (O2 voltage bias) will cause a leaner AFR. Higher values will cause a richer AFR."
QUOTE

That's pretty much plain bull****. Because it's impossible.

NB-O2 sensors are not made to and do not - I repeat: DO NOT - signal a specific mixture except lean (= O2 partial pressure higher than stoich) or rich (= O2 partial pressure lower than stoich). They won't as they can't. Especially not if it comes to a rich mixture. A NB-O2 sensor will also never ever signal constantly 0.50 volts or some other midpoint voltage , unless it's broken. Period, over and out. We have thousands of miles of wideband logging showing clearly, that there's no relation between NB-O2 voltage and mixture except the qualitative determination of being above or below stoich. Run away from people telling you something else, as they prove only having no clue of what they are talking about.

NB-O2 signal varies with O2 sensor temperature and O2 sensor age. A lean voltage of 0.12 volts (typ.) increases to about 0.20 volts, a rich voltage of 0.75 volts (typ.) drops to 0.65 volt. So it seems only reasonable to use an algorithm which is capable to cope with this situation. Every ECU I know of, evaluates only the voltage jump to trigger a EGO correction: if voltage is above rich threshold (~ 0.58 volts) fuel will be reduced, if voltage is below lean threshold (~ 0.42 volts), fuel will be increased. If voltage is between the rich and lean threshold, the signal will be evaluated as erraneous and be ignored. The impact of moving the "error range" on mixture is neglectable, because
a) NB-O2 sensors do not signal a voltage near the thresholds (unless defective) and
b) the integral factor of the PID regulator is chosen that way, that a voltage jump/mixture change is triggered much earlier.
id073897
Wheelie King

Posts: 236
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[AZmidget91]

Would you mind sharing with us what controller you have? Actually I'd like to know everything you have in your setup as I am about to purchase one for my Uly. If possible I'd install two wideband sensors connected to one controller and from it to the ECM. If this setup gets too complicated I can just leave the stock NB in there to feed the ECM and use the WBs only for tuning.

I have 2 LC-1's which won't work with the ECM. I had these before I ever had a Buell, so I just use what I have. If I had the extra money or needed a whole new setup, I would get the DLG-1 which uses a LC-2. From what I have read, it comes with the 4.9 sensors, which would work with the ecm. Even if it only had 1 simulated narrowband analog output, it would be fine for a 03-09 Buell, since they only have 1 narrowband O2. Dean is most likely looking for the dual narrowband output for use with EBR motorcycles.