NefMoto

Technical => Tuning => Topic started by: jibberjive on December 19, 2012, 10:17:11 AM



Title: True automatic map changing flex-fuel setup for ME7
Post by: jibberjive on December 19, 2012, 10:17:11 AM
I think I may have come up with something that could be really cool.  So I am going to be running E85 in my car eventually (likely within the next month), and I was thinking about how to possibly make an automatic map changer based on the ethanol content. 

The ethanol sensor (hereafter referred to as ES) used on the factory cars outputs a PWM signal that tells how much ethanol content the fuel has and the fuel temperature.   The frequency indicates ethanol percentage, such that 50hz=0% ethanol, 150hz=100% Ethanol, and +1hz=+1% eth. The pulse width determines fuel temp such that 1 millisecond = -40*F and 5 milliseconds = 257*F. Both are linear.

So I was thinking about how I could get a PWM input into the ME7 ECU, and I remembered that the EGT's deal with PWM, and the duty cycle of the EGT is what determines the temperature reading.  So looking back at GGATS in the FR (pg 381) the initial inputs from the EGT sensors seem to be

TCCHATS_W   - A High time exhaust gas temperature sensor from CC unit (or the pulse width)

TCCPATS_W   - A Period exhaust temperature sensor bank 2 of CC unit

This got me wondering if the circuity in the plastic EGT box at the connector figures out the pulse width and period, and outputs those via two separate wires, or if the PWM signal goes straight to the ECU and the ECU figures out the pulse width and period itself, and assigns those values to tcchats and tccpats.  Anyone know where the calculation of the pulse width and period take place?  The EGT sensor has 3 wires connecting it (see pic below).  Pin 3 is ground, does anyone know off the top of their head what the other two wires are (I have yet to look at the wiring schematic)?  If we know that one of the other two is a power wire, then we know that the odd-man-out is the PWM signal to tap into.

(http://i297.photobucket.com/albums/mm235/jibberjive/DIYs/EGTsensorconnector.jpg)


If we get TCCPATS_W reading in the value from the ethanol content sensor, we could possibly write a routine similar to the map switching method used in the other thread, but instead of switching the map via the cruise-control stalk (or whatever), it is decided by a variable that is dependent on the PWM frequency from the ethanol sensor.  We could make a map that is setup something like, frequency 0-110 hz (which is 60% ethanol), use map 1, 110-130 hz (80%) use map 2, 130-150hz, use map 3.  And with it set up like this, TCCHATS is a variable that one can log to log the fuel temperature.

Thoughts?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: jibberjive on December 19, 2012, 10:18:39 AM
Another method that I could do (since I already have the Zeitronix ethanol content analyzer gauge) is to use the analog linear 0-5V output from the Zeitronix ECA gauge to input into the secondary cats input, and have the map switching table be based on those voltages.  Obviously there would need to be some limit raising, error/variable disabling, etc to get the secondary cats to read the voltage that high and for those voltages to not be used as the secondary cats normally would. There's some signal conditioning done to those O2 inputs that might be beneficial as well.  I'm not sure what the best way to approach this is, just kind of thinking out loud.

http://www.zeitronix.com/Products/ECA/ECA.shtml


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: jibberjive on December 19, 2012, 10:20:11 AM
Saved


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: elRey on December 19, 2012, 10:29:11 AM
as opposed to frm?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: britishturbo on December 19, 2012, 10:30:27 AM
Pin 1 is the signal :-)

Sounds like a very viable idea!
I'm still going to work on my pwm to voltage converter board though ;-)


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: AARDQ on December 19, 2012, 10:38:19 AM
Not according to Mitchell.  Power is pin 1, ground is pin 3 and signal is pin 2.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: britishturbo on December 19, 2012, 10:43:26 AM
Not according to Mitchell.  Power is pin 1, ground is pin 3 and signal is pin 2.

I'm looking at the Mitchell 1 wiring diagram right now. It shows:

Pin1: Signal
Pin2: Ground
Pin3: +12V


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: britishturbo on December 19, 2012, 10:45:02 AM
(http://i1357.photobucket.com/albums/q755/britishturbo/egt_zps5e587b9d.jpg)


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: jibberjive on December 19, 2012, 11:07:17 AM
as opposed to frm?
I had to search the site to figure out what you are talking about.  I hadn't seen your thread before I started this one, but the concept is the same, just with the trigger being an actual ethanol sensor incorporated into the system rather than relying only on the trims/knock.  Any way to get automatic switching would be awesome.  I would feel better about throwing an ethanol sensor in the mix though personally.


I'm looking at the Mitchell 1 wiring diagram right now. It shows:

Pin1: Signal
Pin2: Ground
Pin3: +12V
I thought, according to Bentley, Pin 1 was some type of power and pin 3 is ground.  Either way though, if there's only one signal wire, then it is carrying a PWM signal and the separation into pulse width (TCCPATS) and period (TCCHATS) are done at a later stage.  And we could quite possibly just splice the ethanol sensor straight in. Looks promising!


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: jibberjive on December 19, 2012, 11:11:54 AM
I'm more of a logic guy and don't have a ton of experience with disassembly/low level programming, but do our ECU's even have enough free space to throw in a routine with like 5 different settings that have 5 different maps per setting (assuming each setting utilizes entirely new maps rather than just multiplying a map by a scalar factor)?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: nyet on December 19, 2012, 11:15:49 AM
Yes, there is a TON of unused space.

There is a question (at some point) of cpu load and fast path timing, but i doubt these modifications will add that much to either.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: britishturbo on December 19, 2012, 11:42:21 AM
One thing to check...

The PWM output from the Ethanol sensor is a 5V signal.
Is the EGT a 12V or 5V signal?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: AARDQ on December 19, 2012, 11:50:04 AM
I'm looking at the Mitchell 1 wiring diagram right now. It shows:

Pin1: Signal
Pin2: Ground
Pin3: +12V

Just went and measured -- you (and Mitchell) are absolutely correct.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: britishturbo on December 19, 2012, 12:05:07 PM
Just went and measured -- you (and Mitchell) are absolutely correct.

I hate it when that happens ;-)


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: DonSupreme on December 19, 2012, 12:40:12 PM
One thing to check...

The PWM output from the Ethanol sensor is a 5V signal.
Is the EGT a 12V or 5V signal?

As I understand it, the ES does not output 5v, its pulls the signal to ground. The receiving component needs to have a signal pull up, 5v for example.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: nyet on December 19, 2012, 12:45:08 PM
A simple FET based buffer circuit could fix this easily, btw.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: prj on December 19, 2012, 12:48:08 PM
Sorry to burst your bubble, but...

Those sensors are very expensive and unreliable.
This is why the OEM's have dumped them and are using feedback from O2's and knock sensors to create a software Ethanol sensor.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: jibberjive on December 19, 2012, 12:56:33 PM
Sorry to burst your bubble, but...

Those sensors are very expensive and unreliable.
This is why the OEM's have dumped them and are using feedback from O2's and knock sensors to create a software Ethanol sensor.
I had heard that the OEM ones were having reliability issues, but they actually quit using them in the US cars?  Because of the questionable reliability, this is the sensor I was planning on trying out, once it has had enough time to get some reviews on it:

http://www.haltech.com/flex-fuel-sensor/


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: jibberjive on December 19, 2012, 12:57:42 PM
A simple FET based buffer circuit could fix this easily, btw.
Fix what?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: DonSupreme on December 19, 2012, 01:04:32 PM
I had heard that the OEM ones were having reliability issues, but they actually quit using them in the US cars?  Because of the questionable reliability, this is the sensor I was planning on trying out, once it has had enough time to get some reviews on it:

http://www.haltech.com/flex-fuel-sensor/

Is that sensor available for purchase? There is no price on that page.

Edit: I found the price. Its $249


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: nyet on December 19, 2012, 02:15:19 PM
Fix what?

.. if there is a voltage mismatch or pullup/pulldown issue


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: britishturbo on December 19, 2012, 06:51:06 PM
The newest GM sensor is only $65 btw...
And as far as I know GM went back to using this newer cheaper, more reliable sensor...


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: jibberjive on December 24, 2012, 02:22:22 AM
The newest GM sensor is only $65 btw...
And as far as I know GM went back to using this newer cheaper, more reliable sensor...
It took some digging to find info on the new GM sensor.  You guys are right, after the failure of the early sensors, GM and Ford went with the "virtual ethanol sensors" that estimated ethanol content via the O2 sensors and fuel level. Now, to comply with the new tier III emission requirements, GM has recently implemented a gen II dielectric flex fuel sensor that actually measures ethanol content again, instead of estimating it.   The gen II sensor is made by the same company who made the first sensors, VDO/Continental.  When digging for info, I made the curious discovery that these look strikingly similar to the Haltech sensor:

http://www.usa.vdo.com/generator/www/us/en/vdo/main/press/releases/aftermarket_replacement_parts/2012/sv_CO1483_C.html

(http://www.usa.vdo.com/generator/www/us/en/vdo/main/press/pictures/aftermarket_replacement_parts/img/img_CO1483_C.jpg)

(http://www.haltech.com/wp-content/uploads/2012/09/article_flex3.jpg)

Like Britishturbo said, these Continental sensors can be had for ~$65, but he didn't mention it's the exact same as the Haltech ($226!).  Pleasant surprise!

The part #'s are 13577394 and 13577379, the difference between the two being the length of fuel connections (the 13577394 being longer).  They can be bought from www.gmpartsdirect.com for ~$66.



Here's some info about the new flex fuel sensor

Quote from:  l
Flex Fuel Sensor

The flex fuel sensor measures the ethanol-gasoline ratio of the fuel being used in a flexible fuel vehicle. Flexible fuel vehicles can be operated with a blend of ethanol and gasoline, up to 85 percent ethanol. In order to adjust the ignition timing and the fuel quantity to be injected, the engine management system requires information about the percentage of ethanol in the fuel.

The flex fuel sensor uses quick-connect style fuel connections, an incoming fuel connection, and an outgoing fuel connection. All fuel passes through the flex fuel sensor before continuing on to the fuel rail. The flex fuel sensor measures two different fuel related parameters, and sends an electrical signal to the engine control module (ECM) to indicate ethanol percentage, and fuel temperature.

The flex fuel sensor has a three-wire electrical harness connector. The three wires provide a ground circuit, a power source, and a signal output to the ECM. The power source is battery positive voltage and the ground circuit connects to an engine ground. The signal circuit carries both the ethanol percentage and fuel temperature within the same signal, on the same wire.

The flex fuel sensor uses a microprocessor inside the sensor to measure the ethanol percentage and fuel temperature, and changes the output signal accordingly. The electrical characteristic of the flex fuel sensor signal is a square-wave digital signal. The signal is both variable frequency and variable pulse width. The frequency of the signal indicates the ethanol percentage, and the pulse width indicates the fuel temperature. The ECM provides an internal pull-up to 5 V on the signal circuit, and the flex fuel sensor pulls the 5 V to ground in pulses. The output frequency is linear to the percentage of ethanol content in the fuel. The normal range of operating frequency is between 50 and 150 Hz, with 50 Hz representing 0 percent ethanol, and 150 Hz representing 100 percent ethanol. The normal pulse width range of the digital pulses is between 1 and 5 ms, with 1 ms representing −40°C (−40°F), and 5 ms representing 151.25°C (304.25°F).

The microprocessor inside the sensor is capable of a certain amount of self-diagnosis. An output frequency of 180 Hz indicates either that the fuel is contaminated, or that an internal sensor electrical fault has been detected. Certain substances dissolved in the fuel can cause the fuel to be contaminated, raising the output frequency higher than the actual ethanol percentage should indicate. Examples of these substances include water, sodium chloride (salt), and methanol.

It should be noted that it is likely that the flex fuel sensor will indicate a slightly lower ethanol percentage than what is advertised at the fueling station. This is not a fault of the sensor. The reason has to do with government requirements for alcohol-based motor fuels. Government regulations require that alcohol intended for use as motor fuel be denatured. This means that 100 percent pure ethanol is first denatured with approximately 4½ percent gasoline, before being mixed with anything else. When an ethanol gasoline mixture is advertised as E85, the 85 percent ethanol was denatured before being blended with gasoline, meaning an advertised E85 fuel contains only about 81 percent ethanol. The flex fuel sensor measures the actual percentage of ethanol in the fuel.

So the "ECM provides an internal pull-up to 5 V on the signal circuit, and the flex fuel sensor pulls the 5 V to ground in pulses".  Does anyone know if that is how the stock EGT's work, with the ECM providing the pull-up voltage?  If so, it looks like it's going to be perfect to use the EGT's 3 wires to power and send the signal from the flex fuel sensor.

I'm banking on these new sensors being more reliable than the old ones, and if they prove to suck, at least they're a lot cheaper. I'm excited to try this out!


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: terok on December 25, 2012, 12:21:31 PM
VAG (propably among others) is using this same Continental sensor in their flexfuel cars, so it can't be that bad :)


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: prj on December 25, 2012, 03:41:54 PM
Seems my info was a little out of date.
I looked into flex fuel a long time ago the last time, and when I looked into it, that was the case.

If they have come up with a cheaper and more reliable sensor, then that is good.

One thing I am worried about slightly - how big is the orifice on the sensor? Is it any good for high power setups? It says that all fuel has to pass through it.
Or am I misreading it?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: britishturbo on December 25, 2012, 03:48:37 PM
Seems my info was a little out of date.
I looked into flex fuel a long time ago the last time, and when I looked into it, that was the case.

If they have come up with a cheaper and more reliable sensor, then that is good.

One thing I am worried about slightly - how big is the orifice on the sensor? Is it any good for high power setups? It says that all fuel has to pass through it.
Or am I misreading it?

Just put a T in the return line and run some of the fuel through it. You're Ethanol % will not change much at all from minute to minute...


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: MIL_on on March 24, 2014, 11:56:17 AM
Hi Guys,
With E85 becoming more and more popular in the Scene even more people see themselves confronted with the problem of lacking e85 gas stations. So the only possibility to do a "flex fuel" is the known method by bringing the FTs to their limits with either one of the fuels and hope that LR will make it fit or be a strict either/or fueller. But wouldnt it be cool if we could fit in a real flex fuel routine?
The sensor for this is easy to get...it even has a VW Partnumber and is fabricated by Continental: 06K907811. I would say the price being ~150€ is also acceptable. Its even easy to install...
Wouldnt it be possible to use the 2nd O2s as an input for the sensor and manipulate fueling and Ignition based on that Voltage?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: ddillenger on March 24, 2014, 12:09:41 PM
Your topic is the exact same as a current discussion. As such, I merged it.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: MIL_on on March 24, 2014, 02:48:49 PM
Oopsie, sorry and thanks! Didnt see this topic in the last days


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: overspeed on March 24, 2014, 03:34:38 PM
here in Brazil, there is no dedicated sensor to measure Ethanol proportion...

All is calculated by logic + O² readings + knock activity (it´s called SFS by Marelli - software Flexfuel System)

I posted some time ago files used by Golf 1.6 EA113 engine Flex (C20 till E100) to someon who want to disassemble and study, but lost the topic (lol)

There is some tricky issues with this metod, but works Ok for factory...


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: RaraK on March 25, 2014, 05:19:58 AM
tune your trims and extend them to allow for a full 30-40% sweep in fueling correction when applying e85, ive done this, and it works, but there is that "cautious" transition when trims catch up.

I also did throw some trim codes here and there, those i then removed.  Kind of a hack, but its what i came up with when i did try this years ago.

Since then i have just made another set of maps to handle for e85. 


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: overspeed on March 25, 2014, 07:41:21 AM
Thats kind of what is made here with SFS...

Just there is some "triggers" to calculate "k" that is the factor to determine how much ethanol is in blend based in knock activity and fuel trim, when K is determinated and saved (my guess) in eeprom (to prevent from a dead battery to have a no-start condition).

there is some triggers, like some fuel beeing put in tank, knock activity with rich moisture, and others I ´don´t know at all

Rarak, in you way, what happens if you have a medium leak ? You can identify it with DTC ?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: RaraK on March 25, 2014, 01:32:41 PM
Thats kind of what is made here with SFS...

Just there is some "triggers" to calculate "k" that is the factor to determine how much ethanol is in blend based in knock activity and fuel trim, when K is determinated and saved (my guess) in eeprom (to prevent from a dead battery to have a no-start condition).

there is some triggers, like some fuel beeing put in tank, knock activity with rich moisture, and others I ´don´t know at all

Rarak, in you way, what happens if you have a medium leak ? You can identify it with DTC ?

No its pretty much a hack like i said.  You dont get ideal cold start ability, but overall running is ok.  Also you will be running lean burn lambda on E85, which is fine in my experience.  If you had a leak of sorts, then you are totally at the mercy of how much of a correction % window you have and if you still have the DTC enabled(or changed the thresholds).

BUT,

Not that i ever tried this logic, i dont see why you can monitor trims, and once you get to a predetermined additive(EX: +25%), switch to another mapset "assuming" you are running E85 based on trims alone.  Software switch :)  Im not sure how its done on the OEM's, nor would i bother reversing it b/c i would say theres only so many ways you can logically do this, my example being one. 

:)  idk just food for thought.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: elRey on October 24, 2015, 10:05:21 AM
Has anyone used one of these GM sensors yet on ME7?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: elRey on November 09, 2015, 11:49:22 AM
Anyone?

I'm not asking for your secrets. I just want to know if there is a light at the end of the tunnel before I start the journey.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: DT on November 09, 2015, 02:22:41 PM
Anyone?

I'm not asking for your secrets. I just want to know if there is a light at the end of the tunnel before I start the journey.
You should not apologise asking for secrets. We need more good stuff to include in our ME7. I have mine connected to the ME7 but at the moment mostly because I can.
I've not done any modification like map switching yet since I rarely ever need to fill up with petrol and if I do I can easily reprogram the ecu. I can log with 0.09766 (2nd O2 input word) in ME7logger, I was planning to do my own solution with an ARM/MIPS solution to convert GM sensor to 0-5V and a couple of 7segment digits (or even output CANbus value) but I never had the time to even start the project, instead I bought a Zeitronix ECA. I never really planned to use the C167 to directly read the pwm signal since I really want to see the actual blend on digits in car.
 


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: elRey on November 09, 2015, 03:38:08 PM
OK. So, you have the GM sensor going thru a Zeitronix controller then into ME7. Thanks.

Which sensor do you have, and can you tell me if the Zeitronix feeds 5v or 12v to sensor's VCC?

Still wondering if anyone as one reading directly into ME7. I'm about to start bench testing.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: Jason on November 15, 2015, 09:36:54 PM
I am looking at this right now too, but I don't want to use an analog input - instead I want to read the digital signal from the sensor and send a message to the ECU with the data.  Analog is the suck.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: mightemouce on March 04, 2016, 02:56:31 PM
Poking around in the Subaru world... couldn't we essential use one of these flex kit http://www.delicioustuning.com/Stage_1_PumpGas  and then feed the signal from their 0-5v converter through an unused rear 02 or EGT signal?

I would imagine there would be a need for some custom code in the me7 to switch files though


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: prj on March 06, 2016, 11:43:32 PM
There is no need to switch files, you need double maps for the stuff that is important, and then you just read both.
Then you blend them the same way as the ECU blends KFZW and KFZW2, except instead of using fnwue you use the E85 factor.
1.00 for E100 and 0.00 for E0.

Look at the FR how it is done (ZWGRU module).


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: Snow Trooper on March 07, 2016, 12:10:09 AM
There is no need to switch files, you need double maps for the stuff that is important, and then you just read both.
Then you blend them the same way as the ECU blends KFZW and KFZW2, except instead of using fnwue you use the E85 factor.
1.00 for E100 and 0.00 for E0.

Look at the FR how it is done (ZWGRU module).

I never thought of lifting the blending method, thank you.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: jmont23 on March 11, 2016, 07:43:37 AM
I just started logging the Zeitronix ECA-2 ethanol% and fuel temp analog output signals. I noticed the signals get much nosier when the engine is turned on vs. engine off, in particular the ethanol% signal is uncomfortably noisy. Since the signals are less noisy with the engine not running, I assume the added noise could be from the fuel flowing through the sensor.

Anyone have similar experiences?

I have the sensor in a -6an (3/8" OD) fuel return hose about 1.5 feet from the regulator. I wonder if this is too close to the regulator?

Engine Off
(http://i1091.photobucket.com/albums/i385/JMont23/Mobile%20Uploads/ECApercent-Good_Signal_engineOFF_zpsmcuyiu0a.jpg)

Engine On
(http://i1091.photobucket.com/albums/i385/JMont23/Mobile%20Uploads/NosiyECApercent_signal_engineON_zpsgwnujukm.jpg)


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: prj on March 11, 2016, 08:43:07 AM
Filter it, done.

new value = old value + delta * K

Where K is your filtering constant.

Or average it.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: rnagy86 on March 11, 2016, 11:34:35 AM
or install an rc filter circuit if you want to do it in hardware


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: jmont23 on March 11, 2016, 12:19:58 PM
Thank you for the suggestion. Yes filtering is certainly an option, but the signal shouldn't be this noisy. Just trying to figure out the root cause.

Zeitronix said this:
"We never seen noise increase due to fuel flow.
A ground offset noise between the ECA-2 and your logger would result in this. Specially since noise is shown on both logged signals.
Ground the ECA-2 right at your logger ground wire."

I'm going to change my ECA-2 ground and retest.



Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: jmont23 on March 11, 2016, 10:17:44 PM
Zeitronix was right. I moved the eca2 ground to my o2 sensor ground and the signal now looks great

(http://i1091.photobucket.com/albums/i385/JMont23/ECApercent-Good_Signal_engine_O2gnd_zpstt1ohiwp.jpg)


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: prj on March 12, 2016, 05:59:23 PM
Much better.

Still could benefit from filtering though if you are going to use it to blend maps.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: kruftindustries on August 16, 2016, 08:39:36 PM
Has any progress been made here? I have that rear 02 wire dangling and it looks like there is enough mental capacity here to make something happen!

My job title is EE at work, I actually write test software but I'd be more than happy to provide a solution to convert the output to whatever you like if that is a hangup. I've been using eurodyne and I'm sick of needing to get out the laptop and warm the car up enough to get into closed loop just to get my tiptronic to slip ::)


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: jibberjive on August 19, 2016, 04:26:15 PM
Has any progress been made here? I have that rear 02 wire dangling and it looks like there is enough mental capacity here to make something happen!

My job title is EE at work, I actually write test software but I'd be more than happy to provide a solution to convert the output to whatever you like if that is a hangup. I've been using eurodyne and I'm sick of needing to get out the laptop and warm the car up enough to get into closed loop just to get my tiptronic to slip ::)

I think the person closest (at least publicly) to doing this is Justin (jmont23 above), though he and the tuner he is working with are going about it slightly differently than this thread was pursuing.  I was (I haven't had much time to pursue any car related for the past while) looking to use the PWM signal directly from the ethanol sensor to hook into the EGT input on the ECU. jmont23 instead purchased the Zeitronix ethanol gauge, which has a 0-5v output, which he is using in the O2 input (rather than the EGT).

I'm still interested in pursuing this when I get some time, though no progress on my end yet.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: woj on November 30, 2017, 04:49:57 AM
Question about the sensors: GM has three types (13577394, 13577379, 13577429), the newest being the smallish one, and then there is the VW version mentioned earlier in the thread (06K907811). I read contradictory information about the characteristics, specifically for the temperature, the bottom temperature threshold for 1ms is always -40*C, but the upper threshold for 5ms pulse is sometimes said to be 125*C, sometimes 150*C, and all this without any specific sensor number reference attached to any of the claims. There is also the mentioning of the 180Hz+ signal to indicate contaminated fuel, but again, no idea if it applies to all sensors. Any info on this would be appreciated.

Another thing - most (all?) of these sensors seem to have 3/8" quick connect pipe. What I'd really need is 5/16", any idea if any of them would have it? The VW one?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: woj on December 01, 2017, 03:52:01 AM
So now one about E85 specific maps. KRKTE and ZW were mentioned in the thread, but that's not all. What I have so far that needs E85 / FlexFuel adaptation / blending is:

KRKTE - fuel portion
ZW/ZWOPT - ignition, I shift them together to prevent spark efficiency from drifting, not sure if that's the way to go
ZWST - starting ignition, a constant offset, seems not to be necessary looking at other E85 solutions, but does not hurt to have
FKSTT - start fuel, a must have for cold starts, looking at factory E85 solutions, drastic increases are needed here
NLLMG(FS) - (slightly) increased idle during warm-up
KFLANS - lambda at warm-up
KFLBTS, LAMFA - basic lambda stuff
KFATMKRH - EGT model, not sure if necessary, but EGTs do drop, might be good to tell the ECU about it.

What else should be on this list? I am planning on having boost maps (MDMAXNMOT / MDMAXNMOB) E85 specific, but I am not after power yet, I am more thinking about seamless and reliable E85 running.



Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: woj on December 07, 2017, 12:43:09 PM
First experiments with the real sensor, though still on the bench, seem to be successful :)


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: amd is the best on December 08, 2017, 02:05:22 PM
I think FKKVS might be worth switching as well. I know my E85 FKKVS is different from my pump fuel FKKVS. Maybe LDRXN so boost level can also be flexed.

Of course the already mentioned KRKTE and ignition timing.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: woj on December 08, 2017, 03:42:13 PM
How much different? I can make a switchable map for FKKVS, no problem, but what worries me is that would not be able to just plug and play E85 the way I want to, even without raising boost / performance, without proper dyno time tuning. So far I have KRKTE map dependant on E85 content and fuel temperature, but it seems the temperature factor should be negligible. Also, even if I make an FKKVS map for E85, does it blend linearly with the gasoline one you think?

EDIT: But I guess you also changed the injectors in the process?

LDRXN is the MDMAX pair of maps on my ECU I mentioned above, I have been just working with these today. Because there is also an overboost version (switchable by either pedal position threshold or pedal use dynamics, all this time filtered), this makes E85 / gasoline switching a bit horrible. Plus I am implementing a power button for this, it is slightly getting out of hand in terms of map / code complication.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: prj on January 05, 2018, 08:55:24 PM
1. Temperature is irrelevant, forget it.
2. FKKVS does not need to be switched. The injector characteristics do not change - if fkkvs needs different corrections at a given pulsewidth, it is likely KFKHFM is baked into it, thus giving issues. Can be switched for ease of use, but should not need to be switched, just extended for the higher pw's reached.
3. ZWOPT does NOT need to be switched, this is totally the wrong way to go and shows comoplete lack of understanding of torque model. Of course spark efficiency goes up and torque goes up, this is normal.
4. Ignition needs to be blended based on a constant that is gathered from a 1D characteristic line, this is because you can most likely already run MBT at E40-E50, so the E85 map needs to be 100% blended in already at that point. Same constant for boost.
5. EGT model is irrelevant, EGT will already be lower on E85 due to advanced ignition and you do not need BTS either because EGT's on E85 are very low.
6. ZWST etc is useless.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: Cloudforce on January 08, 2018, 05:34:46 AM
Hello guys,

is there right now a sensor available that outputs 0-5V from stock?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: prj on January 08, 2018, 07:25:38 AM
Hello guys,

is there right now a sensor available that outputs 0-5V from stock?

No, you need a converter. Can be made a LOT cheaper than for example the Zeitronix, simply by using an Arduino UNO and https://www.adafruit.com/product/935.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: woj on January 08, 2018, 11:41:05 AM
1. Temperature is irrelevant, forget it.
2. FKKVS does not need to be switched. The injector characteristics do not change - if fkkvs needs different corrections at a given pulsewidth, it is likely KFKHFM is baked into it, thus giving issues. Can be switched for ease of use, but should not need to be switched, just extended for the higher pw's reached.
3. ZWOPT does NOT need to be switched, this is totally the wrong way to go and shows comoplete lack of understanding of torque model. Of course spark efficiency goes up and torque goes up, this is normal.
4. Ignition needs to be blended based on a constant that is gathered from a 1D characteristic line, this is because you can most likely already run MBT at E40-E50, so the E85 map needs to be 100% blended in already at that point. Same constant for boost.
5. EGT model is irrelevant, EGT will already be lower on E85 due to advanced ignition and you do not need BTS either because EGT's on E85 are very low.
6. ZWST etc is useless.

6. Not surprised.
5. But that all depends how one decides to tune AFR, doesn't it? I am not saying that AFR tuning through BTS is the proper way to go, but it's good to have the possibility.
4. That I did so far with an intermediate solution,  two E content thresholds that border the use of ZW1 and ZW2, so effectively your propsed 1d map has two cells. Sufficient you think?
2. Good, I was hoping it would be the case.
1. Yes, calculating this based on some scientific data from the Internet says so, but the map is in place, I'll just leave it flat temperature wise.

And 3. :) Don't be concerned with my understating of the torque model, it is where it is supposed to be. At first I wanted to believe I don't need switched ZWOPT, and then I read up a discussion about this in another thread. One thing is for sure, shifting ZWOPT simultaneously with ZW is wrong,  but I gave up on this idea a day or two after I made the first implementation. If vvt systems need two ZWOPTs then E85 need them too due to different burning rate of the fuel. Moreover, the stock calibration of my ECU has ZW very close to ZWOPT in many areas, in fact past ZWOPT by some fractions of a degree in some spots. Surely having ZW heavily past ZWOPT in large areas is conceptually wrong (as much as it can be practically ok).


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: prj on January 08, 2018, 12:05:28 PM
The burning rate for E85 and Gasoline is nearly the same.
You do not need to change ZWOPT.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: Cloudforce on January 09, 2018, 11:29:13 PM
No, you need a converter. Can be made a LOT cheaper than for example the Zeitronix, simply by using an Arduino UNO and https://www.adafruit.com/product/935.

Thanks, will give it a try.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: woj on January 11, 2018, 01:06:25 AM
The burning rate for E85 and Gasoline is nearly the same.
You do not need to change ZWOPT.

I suggest this read:

http://e85vehicles.com/e85/index.php?/topic/1761-spark-advance-vs-fuel-efficiency-gasoline-vs-e85/

I have not yet checked the article they link there, but will.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: prj on January 11, 2018, 07:16:01 AM
I suggest this read:

http://e85vehicles.com/e85/index.php?/topic/1761-spark-advance-vs-fuel-efficiency-gasoline-vs-e85/

I have not yet checked the article they link there, but will.

And what do you think I would learn by doing it?
I don't need to learn someone's theorycraft when I have calibrated the same car on different fuels on my 4x4 chassis dyno to MBT figures. There is nearly no difference in the area that is not knock limited.


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: Mikhail on January 11, 2018, 12:00:29 PM
There is nearly no difference in the area that is not knock limited.
So which side this "nearly" goes with 11CR engine?


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: woj on May 12, 2018, 12:30:09 PM
Trying not to truly double post, just a link for attention: http://nefariousmotorsports.com/forum/index.php?topic=10485.msg115247#msg115247


Title: Re: True automatic map changing flex-fuel setup for ME7
Post by: Jobard on March 09, 2019, 03:53:53 AM
Hello

very interesting.