E38 Flex Fuel: On the fly timing and fueling - anyone interested?

[gmh308]

Anyone interested in this? On the fly adjustment of timing or fueling on E38's.

If so I will write up a "how to".

Works well using EFILive to set things up and then an external independant control to dial in timing variations of your choice or fueling variations of your choice.

Cheers :)

[Tre-Cool]

umm.... YES!!!

[GAMEOVER]

Yes, please...:D

[redhardsupra]

oh sure! if you need any help, please let me know.

[Dmaxink]

I would be interested in this too! :cheers:

[swingtan]

Did you really need to ask? Good work!

[gmh308]

Well I guess that's a quorum and even Marcin and Swingtan are interested!

Anyway brought to you via LSXWorks and the capabilities of EFILive (and hopefull their approval..... We thought about "productizing" this idea, but WTF, just share it for everyone to use! Be green, use ethanol, use less gas, and go fast. So read and implement at your own risk :). No claims are made regarding suitability, legality, or even full functionality. Any issues with operation on GM E38's, please contact GM at Renaissance Centre, Detroit Michigan, USA. :)

As you all probably know GM introduced Flex Fuel quite some time back, maybe 7 or 8 years ago. Not quite sure when exactly.

These days their ECM's support flex fuel with virtual fuel sensing (VFS). I.e. they use the O2 sensors, trims and some other (patented) smarts to run learn cycles to determine the ethanol content of the fuel.

This means they avoid having to fit a "hard" ethanol content sensor in the fuel system to measure the ethanol content and input to PCM/ECM. This sensor lists for around $500 so thats a good thing for customers in that failed $500 sensors no longer need replacing. (even if it probably costs GM $50 or less in quantity).

Given that EFILive kindly exposed the ethanol/flex fuel parameters some time ago:

Flex Fuel Option

{B0178} Flex Fuel Option
{B0184} Flex Fuel Sensor Type
{B0185} Flex Fuel Default Percentage
{B0186} Flex Fuel Sensor Diagnostic
{B0187} Flex Fuel Diagnostic Run Time

Which on 08 OS's at least, do work (well VFS seems a little challenging but thats another story), I figured that maybe GM still had support for hard sensors in the OS's and went looking.

To search was laborious, but it appears GM HAS left hard sensor support in there and it does work, at least on 08 Corvette OS (which also does some other trucks and maybe some cars), and may work on other OS's.

So...the magic pin? Pin 40 on the body connector (J1/X1/C1) of the E38 is the fuel composition sensor input. :)

Using EFILive to set the Flex Fuel parameters up:

Flex Fuel Option

{B0178} Flex Fuel Option = Yes
{B0184} Flex Fuel Sensor Type = Actual Sensor
{B0185} Flex Fuel Default Percentage 80% (set it to what you want, 0 is fine to, but remember it has an effect)
{B0186} Flex Fuel Sensor Diagnostic = Enabled
{B0187} Flex Fuel Diagnostic Run Time = 8 Seconds or less if you want.

DTC P0178 to "non emissions" or emissions if you want.
DTC P0179 to "non emissions" or emissions if you want.

MIL P0178 - No MIL (unless you want to observe the ECM failing the sensor when it sees no input frequency - then: MIL ).
MIL P0179 - No MIL (unless you want to observe the ECM failing the sensor when it sees no input frequency - then: MIL ).

(the DTC/MIL settings are suggested and the following probably works ok without this, but it is worth having a fallback ethanol % operating so if your "sensor" unplugs during testing, you know where things will go.)


Point a 100Hz square wave* into that port and the "Flex Fuel Sensor Frequency" PID kindly reflects that it sees 100Hz on the sensor, and also says that the fuel composition is 50% ethanol on the "Ethanol Fuel Percentage" PID.

Vary the square wave up and down from 50Hz to 150Hz and the % E content runs from 0 up to 85%. The actual range the E38 reads is around 20Hz to 190Hz or something like that, but the composition range runs 0 @ 50Hz to 100% @ 150Hz.

Tested this on several different E38 OS's from 06 through to 08 and the pin number and results are consistent.

So that's the overview of how to manually adjust ethanol content on the fly.

If it is purely flex fuel adjustment you are after, using a simple (or complex if you wish) external oscillator (the famous 555 timer chip is one way of generating the needed square wave pretty simply*) enables ethanol content to be adjusted according to your estimate of what is in the tank, or using your LTFT's just adjust the "virtual fuel composition sensor" until the LTFT's are near zero and you are done.

More on the square wave requirement to follow in the notes below*.

Yes to run ethanol in varying amounts it is possible to simply adjust B3671 to reflect your estimated stoich requirement based on E content, but the beauty of the Flex Fuel access that EFILive enables is that it brings the entire flex fuel subsystem into play. This means trims and other things like "intake valve temp" etc. etc. modelling work correctly.

So...on the fly timing and fueling.

To achieve this adjustability is pretty straightforward.

On the fly timing requires several parameters be setup:


1/. B3671 needs to be flatlined! i.e. running premium gas and you know it stoichs at 14.68 then the whole table needs to be set at 14.68. Running E10 then 14.3 or whatever suits your desires.


2/. B5114 Flex Fuel Spark & B5145 Ethanol Spark Multiplier need to be setup. Some OS's have data in there, some have zero's.

As ethanol content is adjusted/changes the ECM interpolates between the main timing tables and the ethanol spark table B5114 factored against B5145.

So B5114 gives you variability of spark. If you want up to 10 degrees of variance then set B5114 to 10deg across the board. +/- 5deg is obtained via selecting the mid point on the adjustment - 100Hz, calling this your baseline timing and then turning up to 150Hz or down to 50Hz.

If you want +/- 10 deg then set B5114 to 20 deg across the board.

So that's on the fly timing.

On the fly fueling:

This requires a little more detail to setup.


1/. ECM needs to be run in Open Loop. (Swingtan's VVE tutorial can assist with that one).

2/. Tables used are:

B0141, B0142, B0143, B0144 (all for auto, one or the other for manual trans').

B0145 (similar to B5145).

With flex fuel running in the ECM, the ethanol content interpolates between B0141 & B0142 for example for open loop fueling based on factoring from B0145.

Additionally PE tables B3618 and B3670 can be used to vary PE mode fueling.
(haven't tested this angle against the WB).

(Sorry Simon, B3670 does not natively appear for O6 OS's, but maybe it is there in the background just waiting to be exposed. :).)

Anyone that has dug into E38's knows of course that unless speed density mode is engaged and VVE/VE based fueling is used with no MAF, that with a MAF in open loop the ECM limits open loop fueling to an EQRatio/lambda of 1.

That can be fixed luckily (but not necessarily easily) with a cax snippet or an EFILive tune tool addition, and if you want you can try adjusting cruise fueling at up to 1.2 lambda/17.5:1 AFR on gas. PM me for details.

Note 1:

The above has been tested on the road, but not to the nth degree, and probably not on your OS. Proceed at your own risk, effort, and hopefully in the end enjoyment and benefit.

Note 2: *

Using Pin 40:

E38's as you probably know use a regulated 5V for most sensors (not all). The fuel sensor input on pin 40 is no different. The 5V needs to be pulled up and down by the square wave oscillator.

Simply injecting a square wave from an oscillator into to pin 40 will in most cases not work. The oscillator ouput needs to drive a transistor which will sink pin 40 towards ground and back up to 5V again as it oscillates. It seems that it is best if the average voltage on the pin is 2.5V (makes sense) and swings from about 0.5 to 4.5 volts.

Electronics whizzes will know how to do this and maybe could post some details and a suggested circuit/components. :)

But in simple terms something like a BC558 transistor for example with the base driven by the oscillator, emitter to ground, and collector to pin 40 does work, but is dependant on the oscillator output level.

A 555 timer IC will support this, and maybe you will find electronics kits that can be modified, either based on 555, or a digital oscillator that runs off a small microprocessor with a display for the frequency.

Note 3:

Wiring up pin 40.

This is covered in detail in the E38 custom OS thread where a tutorial is available for download.

Note 4:

The PID that GM uses to provide sensor frequency is a little messed up. This is a GM PID issue, not an EFILive issue.

If you go to scan this, it appears differently on the V2 BBL to what it does in the scan tool on the PC. The PC Scan tool has the right readout (unless Paul "fixed" up the PID already). The V2 will read the PID but has a different multiplier.

Note 5:

If tune shops want assistance with this, we will consider offering a support service to help set it up. Various forms of currency are negotiable...normal money, beer, bananas, quid pro quo, beer, sea shells, beer.

Note 6:

Only EFILive offers the depth of flex fuel tuning needed to run this capability. Kudos to EFILive for doing this. Am sure they didnt feel visionary at the time, but they were. :)

Note 7:

The above is a little quick and dirty and leaves some details up to the talents of EFILive users who are a smart bunch anyway and more than capable of connecting the dots.

Edit - Note 8: I neglected to mention that the original hard sensor also supposedly reported fuel temperature via the duty cycle of the square wave. Haven't found anything that points to that.

There you go, long yes, all the details...maybe not. But the core info is there, no guarantees, but as mentioned, there has been on the road testing on and off for a while, but not extensive, so there will be further exploration required, but enjoy!


Cheers.

[GAMEOVER]

Cool!!!...:D

[joecar]

Wow...! Nice piece of work... :cheers:

[ChipsByAl]

Very cool indeed. So anything maybe on the E67? I know its not Pin 40 on the body connector (J1/X1/C1). Was this found out by accident or was someone in the Know?
Al

[swingtan]

Ahh, YES! I had thought about doing something like this a while back but never bothered to really get into it. It's a very good way to adjust things on the fly and as it's pretty easy to make a small square wave generator from an NE-555 timer. I might have a go at this if the car gets repaired and not written off..... :p

Thanks for the info.

Simon

[gmh308]

I might have a go at this if the car gets repaired and not written off..... :p

Thanks for the info.

Simon

Oh dear! :shock: Everyone ok? Or was it that "very hard/heavy" rain you had down there on the weekend?

[Tordne]

It was the weather. There is a thread in the Lounge with pics of the massive hailstones!!

[swingtan]

yes, every one is OK. I saw the size of the hail and instantly knew the cars were going to get damaged. I thought once about putting on a hat and heavy coat, but then figured there was not too much that was going to protect all of me and by the time I get "suited up" the damage would have been done.

Simon

[gmh308]

Very cool indeed. So anything maybe on the E67? I know its not Pin 40 on the body connector (J1/X1/C1). Was this found out by accident or was someone in the Know?
Al

Well I had that question coming didnt I! :)

Dont have a stray license to blow on testing an E67 to check it out at present but it will most likely be one of these pins:

C1 - 5,32,43 or 50
C2 - 26 ???
C3 - 1,2,17,40,41,42,43,54 or 64

At least on an 09 CTS-V cal.

The pin # was the result of a serious search for it based on the assumption that it was there and hope that it was not just "holy grail". And after I found it I was in the know :).

Did ask a few people that might have been in the know about this and they weren't in the know. :shock: Also searched through a lot of different GM schematics and they didnt know either :). So some sleuthing solved the puzzle. :grin:

Cheers.

[gmh308]

yes, every one is OK. I saw the size of the hail and instantly knew the cars were going to get damaged. I thought once about putting on a hat and heavy coat, but then figured there was not too much that was going to protect all of me and by the time I get "suited up" the damage would have been done.

Simon

Wise decision to stay out of the cross fire.

[hymey]

:cheers: Ian

Thanks for sharing, I wasn't sure after chatting to you about it weather or not you would share it,pretty clever you have it working. I think its worth a sticky, your write up looks to be written by an engineering lecturer lol, Simon might pdf it :hihi: Cheers mate this will work good using NOS too

Joel

[JezzaB]

Ahh, YES! I had thought about doing something like this a while back but never bothered to really get into it. It's a very good way to adjust things on the fly and as it's pretty easy to make a small square wave generator from an NE-555 timer. I might have a go at this if the car gets repaired and not written off..... :p

Thanks for the info.

Simon

I think I recall when we were having a conversation about this a couple of years ago but for using it to send a dedicated X hz signal to simulate Ethanol and use the tables for LPG.

Now EFILive has the custom os is makes things alot easier

[hymey]

Biggest advantage with ians setup is adjusting fuel on the fly and getting mbt on the fly then go back and make permanent adjustment.

Ian says he was able to dial in and out timing till knock which is pretty handy, No road runner but its good as its done with a dial d4s tech at its best:)

[swingtan]

I think I recall when we were having a conversation about this a couple of years ago but for using it to send a dedicated X hz signal to simulate Ethanol and use the tables for LPG.

Now EFILive has the custom os is makes things alot easier

That was it! :D

[GMPX]

Guys, forget the 555 timer, too old, will drift with temp. What this really needs is a nice little 8 pin AVR or PIC micro to generate the signal, it would cost about $2.50 for all the parts (if that).

Early on when I was playing around with 'fooling' the ECM in to using the ethanol tables for an LPG application I had suggested to the shop that we were testing with that we make a board that simulates the ethanol signal.
For this LPG application it was decided that on the fly variable ethanol % was not needed, I mean, you are on LPG or you are not! And adding in to the custom OS the option to force the ethanol percentage was much easier.

As a project this could go two ways, a simple dial in the car with some markers on a label to show the percentage of ethanol (cheap), or, something with a 7 segment display showing the percentage selected (expensive).

Lets all be thankful that GM left that legacy code to use a real ethanol sensor even though they have never released a car using the E38 and a flex fuel sensor.

Cheers,
Ross

[gmh308]

Guys, forget the 555 timer, too old, will drift with temp. What this really needs is a nice little 8 pin AVR or PIC micro to generate the signal, it would cost about $2.50 for all the parts (if that).

Early on when I was playing around with 'fooling' the ECM in to using the ethanol tables for an LPG application I had suggested to the shop that we were testing with that we make a board that simulates the ethanol signal.
For this LPG application it was decided that on the fly variable ethanol % was not needed, I mean, you are on LPG or you are not! And adding in to the custom OS the option to force the ethanol percentage was much easier.

As a project this could go two ways, a simple dial in the car with some markers on a label to show the percentage of ethanol (cheap), or, something with a 7 segment display showing the percentage selected (expensive).

Lets all be thankful that GM left that legacy code to use a real ethanol sensor even though they have never released a car using the E38 and a flex fuel sensor.

Cheers,
Ross
Yes great that GM left that code in there and even greater that you uncovered access to it!

Yes I found the 555 based setup also jumped around a lot with noise but I thought that was my lack of expertise with the circuitry. Seems the in vehicle supply line noise was too high as it was only stable with a battery supply. Ran a digital oscillator with a display but that has to have frequency and waveshape setup every power off.

So settled on an AVR with a pot. :). A little over $2.50, but not appreciably and very flexible. :)

[GMPX]

It's funny these days how 'most' small projects are easier to do with an AVR than traditional methods.

[ringram]

Cant efilive be used to intercept the final value of ethanol content via DVT?
Then we would have full control from software and a new roadrunner style approach for E38's!?
Or perhaps a USB controlled device and kit to adapt to pin 40 can be used if it must be a physical input!?

[gmh308]

Just an FYI - some calibrations if set up to fail on no hard sensor and go to default ethanol value as set in the calibration via EFILive wont actually fail.

The ethanol content can still be varied through applying the right frequency but they dont fail if the frequency input is not there.

i.e. if the default value on hard sensor failure is 50% normally the diagnostic will fail the sensor and go to the default value in the diag run time after start up.

Flex Fuel Option

{B0178} Flex Fuel Option Yes
{B0184} Flex Fuel Sensor Type Actual Sensor
{B0185} Flex Fuel Default Percentage 50 %
{B0186} Flex Fuel Sensor Diagnostic Enabled
{B0187} Flex Fuel Diagnostic Run Time 3.0 Seconds

This is not OS specific just calibration specific. i.e. OS 12619078 from a VE/G8 cal wont fail whereas same OS from a Chev truck will fail. No VE/G8 OS's seem to fail, or the earlier VZ OS's.

More flex fuel options still hiding under the covers :).

[Michael55123]

Does this mean I could add a sensor to a G8 from a new VE? Just have to run the wire and fill in the calibration tables?

[GMPX]

New VE, how new? They are E85 capable these days anyway.

[Michael55123]

Yeah, that's what I mean. A VE that has the flex fuel sensor, just meant a "newer" ve, or one with flex fuel capabilities. Anyone have a part# or approximate cost on something like this?

[GMPX]

I think they use different injectors too, so you would need a new set of them (I can't confirm that though). I would expect the whole pump / sender / sensor assembly would run close to $300 - $400 (wild guess).
Aside from that, E85 prices are as expected a joke here in Australia (only a max of 20 cents per/L cheaper), I can't see it being worth your while if you have no other reason other than wanting to run E85 out of curiosity.

[Michael55123]

I already run E85 on my G8. Prices here in Illinois aren't bad at all, 70 cents less than premium, and right now I'm able to get 10 dollars off a fillup in Illinois until the end of June thanks to the Illinois Corn growers association, along with a 340 dollar rebate at the end of the year as long as I use at least 75 gallons. I can run 27-29 degrees of timing at WOT on e85 with no issues, and only about 23-24 on 93. The injectors won't need changed, I'm already running them and injector duty cycle at wot is ~80%. I'd just like the capability of adding the sensor, which I confirmed isn't part of the pump/sender unit, it is indeed a separate unit, just can't find a part number on it. For 400-500 bucks in parts, to have the flexibility of running any blend of gasoline and ethanol would be worth it to me, but if it gets crazy it's not worth it to me, I'll just update my tune to reflect my E85 blend.

[GMPX]

You do have the option that will cost you about $5 and an hour of your time.
Read THIS (http://download.efilive.com/Tutorials/PDF/E38-E67%20Custom%20OS%20Upgrade%20Tutorial.pdf) pdf, you can set the ECM up to switch between 0% and 85% ethanol, whilst not flexible like the sensor you can at least run two tunes.

[L31Sleeper]

The early systems used the Hard Wired E85 Sensor correct ? So the fake square wave module could
also be used on those systems correct ? eg. LS1B 1024K PCM

[gmh308]

The early systems used the Hard Wired E85 Sensor correct ? So the fake square wave module could
also be used on those systems correct ? eg. LS1B 1024K PCM

That's what this thread points to but is not all that explicit. Apologies... :) The references to using i.e. an AVR micro or something similar is in reference to using the a square wave to set ethanol content :). It can also be used to alter fueling and/or timing on the go - like from the dash, if the stoich value is set to a constant via EFILive tuning.

For some reason, GM has elected to go with hard sensors on the MY11 Commodores in Australia, vs their patented Virtual Fuel Sensing system.

[gmh308]

Aside from that, E85 prices are as expected a joke here in Australia (only a max of 20 cents per/L cheaper), I can't see it being worth your while if you have no other reason other than wanting to run E85 out of curiosity.

Ain't that the truth! Given E85 uses around 50% more fuel at stoich than petrol/gas it would need to be ~40% lower in price than regular unleaded to be worth the effort. With the pricing the petrol companies are using to sell E85 at, it increases fuel costs considerably. Message: we dont really want to sell you E85 because it is too hard, and we have petrol (gas) which we are making stunning profits on so why bother with anything else :).

[L31Sleeper]

The E85 Custom OS for the E38 is cool since it has just about every other feature you could
possibly need. But it is a On/Off style. It would be cool to DIAL in fuel and/or timing.

I don't know what an AVR Micro is ??

[gmh308]

The E85 Custom OS for the E38 is cool since it has just about every other feature you could
possibly need. But it is a On/Off style. It would be cool to DIAL in fuel and/or timing.

I don't know what an AVR Micro is ??

google "AVR Micro" ... :)

[samgm2]

I have a question. Why are we looking to enable the old hard wired composition sensor? Why are we not pursuing enabling the Virtual Composition Sensor that is currently employed in every FFV since 2006? I am confused... That path would seem to be the best path for having a far more robust control system with dynamic adjustment of both fuel and spark based only on the O2 sensor readings.

My understanding is that once the VCM detects a change in the fuel in the vehicle of 5 gallons or more, the Virtual Function is enabled in an FFV VCM. What is the difference between the FFV VCM and the non FFV VCM. Are these completely difference OS's or is it just a flag?

[GMPX]

Because some applications don't run the fuel level sensor through the ECM so it has no idea when ethanol may have been put in the tank.

[gmh308]

I have a question. Why are we looking to enable the old hard wired composition sensor? Why are we not pursuing enabling the Virtual Composition Sensor that is currently employed in every FFV since 2006? I am confused... That path would seem to be the best path for having a far more robust control system with dynamic adjustment of both fuel and spark based only on the O2 sensor readings.

My understanding is that once the VCM detects a change in the fuel in the vehicle of 5 gallons or more, the Virtual Function is enabled in an FFV VCM. What is the difference between the FFV VCM and the non FFV VCM. Are these completely difference OS's or is it just a flag?

Two more answers in addition to GMPX Forum Tyhee...esquire... :) Which is very relevant as the VFS ethanol content measuring sequence does not commence until the tank varies by a present amount.

1/. GM in various applications still uses the hard sensor. Holden is one of them.

2/. Getting VFS working on a non factory VFS car has not proven to be a walk in the park. Its much more than a flag. Though a flag can certainly turn if off, it doesnt turn it on. If the VFS tuning is not present in the calibrations due to car/truck not being a VFS model, then the tuning is likely missing. Even with the same OS.

[samgm2]

I don't think this is true. The fact of the matter is that MOST GM's produced since 2005/2006 use a virtual composition sensor. My understanding from talking to GM Goodwrench mechanics is that the detection takes place when five or more gallons are added to the tank. Moreover, the E37 and E38 computers came out AFTER the conventional composition sensors were discontinued. The use of the old composition sensor with these computers shouldn't be required. These OS's support virtual composition sensors.

I went out today and purchased a FFV E-37 and I plan to install it into my non FFV Cobalt. If this test works, then it means that the function is 100% software and we simply haven't found how to enable the virtual composition sensor (software utilizing O2 sensor information).

We need to.


Because some applications don't run the fuel level sensor through the ECM so it has no idea when ethanol may have been put in the tank.

[gmh308]

I don't think this is true. The fact of the matter is that MOST GM's produced since 2005/2006 use a virtual composition sensor. My understanding from talking to GM Goodwrench mechanics is that the detection takes place when five or more gallons are added to the tank. Moreover, the E37 and E38 computers came out AFTER the conventional composition sensors were discontinued. The use of the old composition sensor with these computers shouldn't be required. These OS's support virtual composition sensors.

I went out today and purchased a FFV E-37 and I plan to install it into my non FFV Cobalt. If this test works, then it means that the function is 100% software and we simply haven't found how to enable the virtual composition sensor (software utilizing O2 sensor information).

We need to.

Oh well. Best of luck. :) When the GM Goodwrench mechanics can tell you why GM uses hard sensors on 2011 vehicles when they could use VFS, please share the thinking with all of us. Current OS's support both hard and virtual sensing. And agreed, it IS in the software. If GM Goodwrench mechanics can tell you where, that would be great to know. :)

[samgm2]

Which 2011 GM vehicles use a hard fuel composition sensor?


Oh well. Best of luck. :) When the GM Goodwrench mechanics can tell you why GM uses hard sensors on 2011 vehicles when they could use VFS, please share the thinking with all of us. Current OS's support both hard and virtual sensing. And agreed, it IS in the software. If GM Goodwrench mechanics can tell you where, that would be great to know. :)

[gmh308]

Which 2011 GM vehicles use a hard fuel composition sensor?

If you are in the US you would know them as Pontiac G8. Holden Commodore. V6 and V8 models. Also known as Chevrolet Lumina in Middle East and Sth Africa.

[samgm2]

The G8 was introduced in the US in 2008 and was produced until 2009 (2 years).
In addition, a search of alldata reveals that no fuel composition sensor was used in either year.

The Lumina was discontinue in 2001 in the US.

I have yet to verify the use of a fuel composition sensor after 2002, although I have found references to a couple in 2006. That said, there are inaccurate references in this thread for cars made in 2011.

That means the hard sensor has been gone for AT LEAST seven years in all cars and in most cars for more than a decade. So why would new computers support it?

The use of a hard fuel composition sensor in any vehicle is ill-advised. We should turn our attention to enabling the virtual function in ALL vehicles.

My experiments with E-85 tunes reveals that with proper advance (12-18 degrees), E-85 yields equivalent or superior mileage and power to gasoline.

Estimates of mileage based on combustion energy alone, border on meaningless. Equally important is the reversibility of the reaction. Alcohol burns much slower and is thus much more efficient for converting heat to energy.

There has GOT to be a parameter that turns the virtual composition sensor on.

Once I deal with VATS, I will test a 2009 Flex Fuel E-37 with a non flex fuel 2007 Cobalt. Either it will work or it will not.

If it works, it means that the function is FULLY enabled by software and we just haven't found all the parameters to enable it. If it doesn't, it means that an external signal is missing in the non-flex fuel vehicle.

If it is fully in software, I would guess that there may be a hunting rate parameter or a loop gain(s) parameter(s) that may have zeros in it (for non FFV).

Sam
Chemical/Controls Engineer


If you are in the US you would know them as Pontiac G8. Holden Commodore. V6 and V8 models. Also known as Chevrolet Lumina in Middle East and Sth Africa.

[L31Sleeper]

Sam, don't take this the wrong way, but do some OVERSEAS GM vehicle research.
Check out Holden, Vauxhall and Chevy in other countries. The overseas Lumina is
a re-bagged 04-06 GTO.

-Justin

[gmh308]

The use of a hard fuel composition sensor in any vehicle is ill-advised. We should turn our attention to enabling the virtual function in ALL vehicles.

My experiments with E-85 tunes reveals that with proper advance (12-18 degrees), E-85 yields equivalent or superior mileage and power to gasoline.

Estimates of mileage based on combustion energy alone, border on meaningless. Equally important is the reversibility of the reaction. Alcohol burns much slower and is thus much more efficient for converting heat to energy.

There has GOT to be a parameter that turns the virtual composition sensor on.

Once I deal with VATS, I will test a 2009 Flex Fuel E-37 with a non flex fuel 2007 Cobalt. Either it will work or it will not.

If it works, it means that the function is FULLY enabled by software and we just haven't found all the parameters to enable it. If it doesn't, it means that an external signal is missing in the non-flex fuel vehicle.

If it is fully in software, I would guess that there may be a hunting rate parameter or a loop gain(s) parameter(s) that may have zeros in it (for non FFV).

Sam
Chemical/Controls Engineer

The 2011 Holden Commodore (G8 basis until Pontiac shut its doors, but coming back as the Chevy Cop Caprice) V6 and V8 flex fuel cars use a hard sensor (IIRC that may be all models for 2011). It can be purchased NOW as a spare at a GM/Holden dealer for the 2011 cars. The information, oddly enough, is accurate.

Really interested in how you manage to get better mileage out of E85 than gasoline when at stoich its flowing roughly 45% more fuel by weight.

VFS CAN be turned on in GM controllers. EFILive opened this door maybe 2 years back. It just doesnt want to work as it should. Even tried stock FF tunes and VFS wont run. So yes, there is an input missing as you mention that it needs to validate the process and then run the learn cycle. It uses both fuel level and fuel tank pressure to commence the cycle...though now I cant remember for sure whether I ran a simulation as well for the fuel tank pressure. Maybe I didnt. It was about a year back. Must swap the E67 out and put an E38 back in and give it shot again. :)

And as LS1Sleeper pointed out, just because something isnt available in the US, doesnt mean it isnt available somewhere else on the planet where the other 95%+ of the inhabitants of earth hang out. The rest of the world is not the 52nd and 53rd states of the US :), Chevy's are sold in the middle east (Dubai etc...they have cheap gas and a speed crazy... :cool:), south africa, and the car the G8 was derived from is the largest selling car in Australia, and also exported to the UK and Singapore and middle east countries (Chevrolet Luminas), etc, in some forms.

[samgm2]

Relax a bit. This isn't a battle. If as a group we are able to find out why the flex fuel function isn't working, this will be good for everyone.

If Efilive can play a significant role in this???...

Or... would we rather continue to supply the middle east with oil dollars while at the same time the NON OPEC countries continue to be bled?

Yes, you can get better mileage from E-85 because the reaction is more reversible. I currently lead a design effort for an engine based on E-85, E-100 and M-100 (Methanol). The efficiency of a pure methanol engine running at high compressions is more than twice that of gasoline!

Yes, the energy content of the fuel is primary in determining mileage. Just as important however are:

1. The reversibility of the reaction.
2. The compression ratio.

The brake efficiency of a gasoline engine (assuming reversible conditions) is only 18%. The brake efficiency of an alcohol engine (at a CR of 20:1) is 48%! This exceeds even diesel which sits at 40%.

Gasoline is lousy fuel. Alcohol is superior in nearly every respect. Methanol trades for about $1.00 per gallon and the US currently produces more than 3.6 Billion gallons per year of it from Natural Gas. This is a fuel we can make rapidly here in the US.

Since I am talking only about code modification in this case and I am not altering the compression ratio. The gain in efficiency is due ONLY to the far more reversible reaction that takes place with Alcohol fuels. So yes, despite the fact that the energy content of E-85, a greater percentage of the energy in E-85 will convert to useful work.

In an Ecotec 2.2 liter engine the following resulted in a dramatic increase in mileage for E-85.

1. High octane spark table copied into low octane spark table.
2. Added additional 8 degrees to low octane spark table.
3. Added 12 degrees to high octane spark table.

Additionally, I have been heading a research effort at my company and have developed an optimized procedure for determining optimal spark. Once completed, I will release the algorithm (and likely, the full program) to the public.

Finally, your logic that at a particular flow rate of air the E-85 required will be 45% more than gasoline is flawed. That assumption presumes the same efficiency. What I am saying is that you will need less air and therefore less E-85 to make the same power because efficiency has increased.

Sam
Chemical Engineer/Research Scientist


The 2011 Holden Commodore (G8 basis until Pontiac shut its doors, but coming back as the Chevy Cop Caprice) V6 and V8 flex fuel cars use a hard sensor (IIRC that may be all models for 2011). It can be purchased NOW as a spare at a GM/Holden dealer for the 2011 cars. The information, oddly enough, is accurate.

Really interested in how you manage to get better mileage out of E85 than gasoline when at stoich its flowing roughly 45% more fuel by weight.

VFS CAN be turned on in GM controllers. EFILive opened this door maybe 2 years back. It just doesnt want to work as it should. Even tried stock FF tunes and VFS wont run. So yes, there is an input missing as you mention that it needs to validate the process and then run the learn cycle. It uses both fuel level and fuel tank pressure to commence the cycle...though now I cant remember for sure whether I ran a simulation as well for the fuel tank pressure. Maybe I didnt. It was about a year back. Must swap the E67 out and put an E38 back in and give it shot again. :)

And as LS1Sleeper pointed out, just because something isnt available in the US, doesnt mean it isnt available somewhere else on the planet where the other 95%+ of the inhabitants of earth hang out. The rest of the world is not the 52nd and 53rd states of the US :), Chevy's are sold in the middle east (Dubai etc...they have cheap gas and a speed crazy... :cool:), south africa, and the car the G8 was derived from is the largest selling car in Australia, and also exported to the UK and Singapore and middle east countries (Chevrolet Luminas), etc, in some forms.

[GMPX]

Or... would we rather continue to supply the middle east with oil dollars while at the same time the NON OPEC countries continue to be bled?
I would love to give money money to the farmers up in Queensland who produce our E85 fuel as you would like to see your money go to local US farmers, but when the cost price does not out way the additional fuel used what is the point?
For me, the Australian government stuffed up on the pricing. By my calculations, the extra fuel used on E85 it needs to be priced about 35 - 40 cents per litre cheaper, currently it's only 20.

I think I recall Buick marketing the direct injection turbo 4 in 2012 will get the same fuel economy on regular or E85.

I have been contemplating doing some serious tuning on my car on E85 to try to get the fuel economy better, but I don't 100% understand the ideal calculations on fuel ratios and timing for E85.

[gmh308]

I would love to give money money to the farmers up in Queensland who produce our E85 fuel as you would like to see your money go to local US farmers, but when the cost price does not out way the additional fuel used what is the point?
For me, the Australian government stuffed up on the pricing. By my calculations, the extra fuel used on E85 it needs to be priced about 35 - 40 cents per litre cheaper, currently it's only 20.


Ditto. In Sydney 10c per litre differernce at one station tonight :(. E85 costs more to run that regular ole gasoline.

[gmh308]

Relax a bit. This isn't a battle.

Sam
Chemical Engineer/Research Scientist

:) I guess thats why you were battling the truth bru, and asserting inaccurate information was being stated :rolleyes:.

[gmh308]

Finally, your logic that at a particular flow rate of air the E-85 required will be 45% more than gasoline is flawed. That assumption presumes the same efficiency. What I am saying is that you will need less air and therefore less E-85 to make the same power because efficiency has increased.

Sam
Chemical Engineer/Research Scientist

Great to hear there is work going on to unleash the efficiency potential of methanol.

Well if we are talking a regular production engines on E85, vs optimised designs running on methanol which at present are out of reach with very high compression ratios that will also run regular gas, if the engine is running closed loop, at 9.8:1 we are talking 45% more liquid than gasoline at 14.7:1. Yes or no? Approximately that is, give or take a few points of specific gravity differences. Maybe my math is wrong. :)

That said, appreciate your insight into how "reversibility" of the combustion process is applicable to a current and regular production engine. Isnt that getting in to a little Alchemy? :)

[samgm2]

I head an automotive engine research division at my company.

The information I've provided is accurate. Moreover, my motives for disseminating it are pure and intended to help move us away from an unsustainable fuel source that continues to be the primary source of income for countries that hate us.

I would like to apologize to my friends from NZ. I had no idea that EFILive was based out of NZ until I ordered it Friday of last week. I had no intention of presenting the US as the only market out there. I simply have little access to the rest of the world in my day to day life and I mean no disrespect. On the contrary, I have always had the highest respect for the people of New Zealand and their respect for the environment.

That said, it is the attacks against alcohol fuels that are inaccurate. Alcohol fuels have yet to realize their potential. The engines being produced by the Auto manufacturers today can best be characterize as "ALCOHOL TOLERANT". Stated simply, they are gasoline engines FIRST and E-85 is simply an afterthought. Tuning PCMs to maximize E-85 efficiency WILL result in dramatic improvement - often exceeding the MPG and power of gasoline.

The book "Energy Victory" by Dr. Robert Zubrin is an excellent source of information regarding alcohol fuels, their potential and the reason we don't have them to any meaningful degree.

Gasoline enjoys a monopoly that is very difficult to break. Auto manufacturers aren't in bed with the oil companies. They ARE the oil companies. It is in their best interest to continue to destroy the efficiency of alcohol as a fuel.

Think of the car as the printer and gasoline as the ink. You can buy a very cheap printer because the inks are going to be a constant source of income for the printer manufacturers.

We will NEVER have a meaningful alternative fuel option if auto manufacturers have their way.

The assertion that gasoline has more energy per volume than alcohol is accurate, but energy content alone is not definitive for work output or determination of MPG.

There are two ways to dramatically increase the efficiency of an engine.

1. Slow the flame front.
2. Increase the compression ratio.

In both cases, alcohol wins. There is simply no competition. An alcohol engine can support compression ratios in excess of 20:1. Try that with gasoline.

As for a slower burn (a more reversible reaction), once again alcohol wins. The gasoline in E-85 actually hurts more than it helps with this. Since often the "gasoline" used in E-85 contains higher ratios of n-Octane to iso-Octane, the resulting octane number can be as low as 94. This is a dramatic reduction in octane number from the 105 or 106 for neat ethanol or methanol.

Gasoline is a pathetic fuel. It simply burns far too quickly.

Keep in mind that it was a waste product produced during distillation of crude oil in 1860 (the product they were after was lamp oil). For 40 years, gasoline would be dumped into the Ohio river. This resulted in the Ohio river becoming the most polluted river on the planet (catching fire 7 times). The perfection of the Otto Cycle by Nicholas Otto made available an engine that could run on a waste product. That made it cheap and desirable. But that doesn't change the fact that gasoline is a bad fuel. The only reason to use it is if it is available cheaply. This is no longer the case. Gasoline is becoming outrageously expensive and wreaking havoc on the economies of NON OPEC countries around the world.

EfiLive, along with other companies of their type and the DIY community is in a unique position to expose the truth regarding alternative fuels. The DIY communities have long been a source of inspiration to large manufacturers as well as a means of keeping them honest regarding what is really possible.

Sam
Research Scientist
Chemical/Controls Engineer


:) I guess thats why you were battling the truth bru, and asserting inaccurate information was being stated :rolleyes:.

[samgm2]

Not alchemy but rather, thermodynamics.

I have seen much with regards to the application of Hess's law in determining and comparing potential mileage (a comparison of combustion energy). That said, Hess's law is to thermodynamics what kindergarten is to education. It is a beginning.

Thermodynamics goes far beyond simply comparing combustion energy. For our purposes, it examines reversibility and its effect on converting heat to work. The foundation of thermodynamics as a science begins with the Carnot Cycle. The Carnot Cycle begins by assuming a reversible reaction. You can think of a reversible reaction as one that is infinitely slow (one grain of sand being added on top of the piston at a time).

The faster the reaction, the less efficient it will be. Diesel engines have far more reversible reactions that gasoline engines - making them more efficient (not to mention their higher compression ratios which also make them more efficient).

On the molecular level think of the molecules that compose the lattice of the piston being hit by very fast moving combustion product molecules and a vibration being induced (heating) as opposed to displacement (work).

It is the difference between pushing your friend slowly with one finger vs slapping him. One causes displacement, the other heating (and perhaps a fight). We are not interested in HEATING our pistons, we are interested in moving them.

...but did you know that if you had a higher compression Otto-Cycle engine, it would be more efficient that a diesel engine? In fact, the otto-cycle is superior in efficiency to a diesel cycle. The problem is that we have to run compression ratios that are far lower than those of diesel BECAUSE of the poor characteristics of gasoline. The long carbon chains and non-polar nature of gasoline molecules make it an easy target for the oxidizer. Alcohol suffers MUCH less from these limitations. It's polar nature and the presence of a far less reactive Oxygen molecule reduce the number of reactive collisions and thus the rate of reaction (also known as the reaction kinetics).

Liquid fuels have proven themselves to be convenient and effective. We have developed the infrastructure necessary to support them. Methanol can be produced from many sources. It is easily made from Natural Gas, Coal, Biomass, etc. The US produces in excess of 3.6 Billion gallons of Methanol per year from NG. I imagine that NZ does as well. It trades for about $1.00 per gallon...

Methanol production can be sustainable, doesn't have to come from food products and can be made from fossil fuels until we ramp up production of sustainable non-food plant matter. The use of Ethanol now is a good way to start towards production of methanol in the future. Farmers will now have TWO crops. The part that humans eat and the part of the plant that is inedible and can be easily converted to methanol.

(Biomass or NG or Coal or Dog droppings) + Steam -> Syngas (CO + H2)

CO + 2H2-> Methanol (over copper catalyst)
CO2 + 3H2 -> Methanol + Water (same catalyst)

This is an old reaction that we have used for a long time.

So, why are we do obsessed with gasoline... The smear against alcohol fuels has been long winded and purposeful... It harms us all. Our planet is suffering because of this fuel.

So yes, methanol has half the energy of gasoline, but with the proper engine, the efficiency for work conversion will go up by more than 200%!

As an analogy, assuming that you have 100 Joules of energy available (from gasoline) and you can convert 18% of that energy into useful work. You would get 18 Joules of work out of your engine.
Now assume you only have 50 joules of energy (from methanol) but you can convert (48% of that energy to useful work). You would get approximately 25 Joules of work out of your engine. Half the energy, but more useful work performed.

This is what we are talking about.

Yes, for a given quantity of air, more methanol will be needed to affect complete combustion. What I am saying is that your throttle plate will be closed more because you will need less power output because your engine will be more efficient. Less air for more work and therefore less fuel overall.



I say again, the solution will begin in the DIY community. Perhaps embarrassing the auto manufacturers can affect some change.


Great to hear there is work going on to unleash the efficiency potential of methanol.

Well if we are talking a regular production engines on E85, vs optimised designs running on methanol which at present are out of reach with very high compression ratios that will also run regular gas, if the engine is running closed loop, at 9.8:1 we are talking 45% more liquid than gasoline at 14.7:1. Yes or no? Approximately that is, give or take a few points of specific gravity differences. Maybe my math is wrong. :)

That said, appreciate your insight into how "reversibility" of the combustion process is applicable to a current and regular production engine. Isnt that getting in to a little Alchemy? :)

[joecar]

We're interested in lowering our ET/TS in the quarter on our current hardware and want to stay within our small budget (if something breaks we have to be able to replace it cost-effectively)... how can alcohol/methanol help us...?

( for the average car guy, this is what it comes down to )

:)

[L31Sleeper]

I say we cut this thread in half and send the second half to the Lounge ??

-Justin

[samgm2]

Both E-85 and M-100 (Methanol) will increase efficiency. So power WILL go up even if you have to burn more fuel.

I recently "rough tuned" a 2007 Chevy Cobalt. Stock tune with gasoline was 122 HP at the wheels.

Copied the HO Spark Table into the LO Spark table and adding 10 degrees of additional advance to the HO table and 6 degrees to of additional advance to the LO spark table resulted in an increase in power to 136 HP (Methanol) and 134 HP for E-85.

Mileage tests on gasoline for a 262 mile test (highway)
36 MPG Gasoline.
38 MPG E-85 - no hardware mods required.
30.3 MPG M-100 - one 35 cent seal required.

No detonation for either E-85 or methanol. I've done some reading about NZ. Apparently your country imports ALL of its oil. A while back, there was a program to produce synthetic gasoline.

Methanol -> Dimethyl Ether -> Propanol -> gasoline.

Very expensive and there is no need. You can run very well on methanol alone. Increasing the compression ratio in your engines will result not just in improved efficiency but also avoids cold starting issues.

In about 2 weeks, I will be testing a new algorithm for determining the most efficient spark table and will publish the tables for engines as I test them.

Here in the US, the cost of gasoline is running about $3.50/Gal. E-85 is about $2.90. M-100 is trading for about $1.04-$1.23 per gallon (varies daily). Of course, I am forced to run Reagent/Lab grade methanol purchased at $3.00 per gallon.

If we are to compare cost of driving on Methanol to Gasoline. The gasoline vehicle would have to get mileage 3x that of Methanol to equal the cost per mile driven for Methanol. Methanol is just a great fuel.

Yes, I realize that most on this site are interested in quarter mile times. (As am I, since cars are both a hobby and a profession for me) but seriously, the average "Joe" is interested in mileage not the quarter mile.

As for cars, I was first to put a Corvette Z06 engine into a Mazda Miata ("LS1 Bound" on Miata.net). I have two Corvettes (one that ran in Bonneville at 276 MPH) and one that is currently being set up as an open road racer.

I just think that mileage is more important for BOTH of our countries.


We're interested in lowering our ET/TS in the quarter on our current hardware and want to stay within our small budget (if something breaks we have to be able to replace it cost-effectively)... how can alcohol/methanol help us...?

( for the average car guy, this is what it comes down to )

:)

[gmh308]

Keep in mind that it was a waste product produced during distillation of crude oil in 1860 (the product they were after was lamp oil). For 40 years, gasoline would be dumped into the Ohio river. This resulted in the Ohio river becoming the most polluted river on the planet (catching fire 7 times). Sam

Research Scientist
Chemical/Controls Engineer

Are you serious? People dumped gasoline, ongoing, into the Ohio river. My god we have come a long way...luckily.

Got you on the combustion speed of gasoline. The impulse of the reaction. Needs to be more like the application of energy by a person on a bike.

Thanks for the overview. Very in depth. Interesting what you got out of the Cobalt with no comp ratio changes. The power increase sounds typical. Was it still running closed loop? If so, it means that just increasing the timing created so much more torque, that the airflow through the engine was reduced by a considerable amount and MPG went from a typical 25-30mpg on E85 up to 38mpg.

Looking forward to your work on the optimal timing. That could get my E85 drinking LS7 down to much cleaner gas type mileage while still making a lazy 700Nm TQ. (well, clean, acetyldehyde and formaldehyde aside :( ).

EFIlive is not all NZ. :) GMPX is in "Melben" as his sig says. And Mr Blacky resides in NZ, but I believe he is an Aussie as well.

I know a guy in the oil and gas business in Singapore...he got into that industry 20+ years ago. Apparently there was an oil shortage back then as well and continuously since. Nothing has changed except the price. Yes I agree, its all about money.

Smokey Yunick managed to build a very thermally efficient gasoline engine maybe 30 years ago. High power, low fuel consumption. That didnt get far. Killed off I guess. Hope your work survives. :)

[samgm2]

Good analogy on the bike. Imagine if you slapped the pedals really hard - it just wouldn't yield much.

The history of gasoline is very interesting.

It was called gasoline because it was so volatile. If you put a can of it down and came back a day later, half of it was gone. Hence: GAS-O-LINE. The first part means it turns into a GAS.

The word Kero as in Kerosine comes from the Greek "Kero" which means waxy.

Fortunately we no longer dump gasoline into the Ohio and it no longer catches fire because Otto's engine found was able to use the waste product.

Nicholas Otto's engine caught on, BECAUSE it burned a waste product - so the inefficiency caused by the extremely low compression ratios didn't matter. The stuff was almost free (you just had to pay transportation costs).

Had gasoline not been available, the engine would have run on alcohol and would have had a much higher compression ratio (perhaps 20:1). This would have radically changed its efficiency.


Are you serious? People dumped gasoline, ongoing, into the Ohio river. My god we have come a long way...luckily.

Got you on the combustion speed of gasoline. The impulse of the reaction. Needs to be more like the application of energy by a person on a bike.

Thanks for the overview. Very in depth. Interesting what you got out of the Cobalt with no comp ratio changes. The power increase sounds typical. Was it still running closed loop? If so, it means that just increasing the timing created so much more torque, that the airflow through the engine was reduced by a considerable amount and MPG went from a typical 25-30mpg on E85 up to 38mpg.

Looking forward to your work on the optimal timing. That could get my E85 drinking LS7 down to much cleaner gas type mileage while still making a lazy 700Nm TQ. (well, clean, acetyldehyde and formaldehyde aside :( ).

EFIlive is not all NZ. :) GMPX is in "Melben" as his sig says. And Mr Blacky resides in NZ, but I believe he is an Aussie as well.

I know a guy in the oil and gas business in Singapore...he got into that industry 20+ years ago. Apparently there was an oil shortage back then as well and continuously since. Nothing has changed except the price. Yes I agree, its all about money.

Smokey Yunick managed to build a very thermally efficient gasoline engine maybe 30 years ago. High power, low fuel consumption. That didnt get far. Killed off I guess. Hope your work survives. :)

[gmh308]

Good analogy on the bike. Imagine if you slapped the pedals really hard - it just wouldn't yield much.


Yes, full power on the crank of a bike at TDC will take one a long way right! Rising power to 90 deg probably most effective.

Very informative. Gas-o-line. How much damage has unburned HC from that evap source done over time to the planet? I would guess there is more HC burned each day as waste on oil platforms than the entire motor vehicle population of the planet. Roughly speaking, one single platform off the north west coast of Australia, in one day, from its waste flame, creates more CO2 than the entire car/truck population in Sydney (4.5m people) does in a day.

[GMPX]

Sam, I wish I had more time to experiment with an E85 specific tune for my car. It's the 3.0L LFW V6, direct injection with 11.7:1 compression, factory flex fuel. Unfortunately there is no specific adjustment to the cam timing on these engines based on the ethanol content (or we haven't found the table), this is an area I've played around with on normal gasoline but it's too prone to knock once you start playing around with the dynamic compression by altering the cam timing.

[gmh308]

Sam, I wish I had more time to experiment with an E85 specific tune for my car. It's the 3.0L LFW V6, direct injection with 11.7:1 compression, factory flex fuel. Unfortunately there is no specific adjustment to the cam timing on these engines based on the ethanol content (or we haven't found the table), this is an area I've played around with on normal gasoline but it's too prone to knock once you start playing around with the dynamic compression by altering the cam timing.

Any mileage measurements on E85 Ross?

[L31Sleeper]

Sam, I wish I had more time to experiment with an E85 specific tune for my car. It's the 3.0L LFW V6, direct injection with 11.7:1 compression, factory flex fuel. Unfortunately there is no specific adjustment to the cam timing on these engines based on the ethanol content (or we haven't found the table), this is an area I've played around with on normal gasoline but it's too prone to knock once you start playing around with the dynamic compression by altering the cam timing.

Wow......to think all this time I thought you were just a programmer....
...oh wait that's paul. Ha ha

-Justin

[GMPX]

Any mileage measurements on E85 Ross?
91 Octane about 12.4L/100 city, on E85 15.8L/100. Feels lazy on E85 too. This was only reading 65% ethanol too as the tank was not empty when I put E85 in, so I expect it to be a little worse on full E85.


Wow......to think all this time I thought you were just a programmer....
...oh wait that's paul. Ha ha
I don't know, i just copied from something Google found :hihi:

[gmh308]

91 Octane about 12.4L/100 city, on E85 15.8L/100. Feels lazy on E85 too. This was only reading 65% ethanol too as the tank was not empty when I put E85 in, so I expect it to be a little worse on full E85.



Oki doki thx. Your mention of the VVT raises a good point, as the combination of VVT and ethanol makes it difficult to see what the timing needs to be without VVT.

Anyone have a 2011 VE Commodore V8 tune they could post? Being a VVT free engine... :)

[samgm2]

I will be developing a more accurate tune for several ECOTEC engines. We will also be developing a more sophisticated algorithm for valve timing.

With such a compression ratio, you should be able to surpass both power and efficiency dramatically with and optimized E-85 tune. It should easily surpass what is possible with gasoline.

Did your engine come with 11.7:1 compression stock?


Sam, I wish I had more time to experiment with an E85 specific tune for my car. It's the 3.0L LFW V6, direct injection with 11.7:1 compression, factory flex fuel. Unfortunately there is no specific adjustment to the cam timing on these engines based on the ethanol content (or we haven't found the table), this is an area I've played around with on normal gasoline but it's too prone to knock once you start playing around with the dynamic compression by altering the cam timing.

[GMPX]

Yes, according to GM's press release the LF1 / LFW are 11.7:1 comp.

[NateD4]

I'm working with a 3900 V6 LZG engine (VVT, DOD, & Flex Fuel ). So far it looks like it uses the E38. Any idea if the Flex fuel sense option will work on this version of the OS?

It'd be a great thing to have when I drop a VGT turbo on it (Assuming I don't need an E67).

[samgm2]

I have yet to find anyone that has confirmed that the flex parameters actually enable flex fuel operation. So far I have confirmed that people can shut it off, but I know of no one that has turned it on when it was off by default. This was certainly true of HP Tuners. Their flex fuel stuff didn't work for turning the function on. EFILive appears to have discovered more of the parameters, however. I am very interested in the answer and might just go ahead and burn up another license to find out.

I am in the process of installing our dyno at work. I expect it to be up and running next week. I expect to be able to derive some really good tables for both E-85, E-100 and M-100. I will make them available when I finish. Unfortunately, all of these engines are 4 cylinder for now. I will move to a v8 next (L92). Probably a v6 after that.

[samgm2]

Boy, no kidding. I am 50. The 555 was old when I was a kid! I wouldn't use a 555 for anything anymore.

I completely agree about the AVRs. They are awesome. I just wish that documentation from ATMEL was a bit better. I've currently developing with a UC3C0512c. Amazing part. 32 bit, 66 MHz, 100 MHz DSP, 16 A/D ports, 2 DACs, I2C, SPI, USB, Flash, external memory support, great RISC instruction set and an industrial rating! It blazes! All for less than $20 in low quantities! Now that ATMEL has switched their IDE to microsoft, even the development environment has taken a giant leap forward.


Guys, forget the 555 timer, too old, will drift with temp. What this really needs is a nice little 8 pin AVR or PIC micro to generate the signal, it would cost about $2.50 for all the parts (if that).

Early on when I was playing around with 'fooling' the ECM in to using the ethanol tables for an LPG application I had suggested to the shop that we were testing with that we make a board that simulates the ethanol signal.
For this LPG application it was decided that on the fly variable ethanol % was not needed, I mean, you are on LPG or you are not! And adding in to the custom OS the option to force the ethanol percentage was much easier.

As a project this could go two ways, a simple dial in the car with some markers on a label to show the percentage of ethanol (cheap), or, something with a 7 segment display showing the percentage selected (expensive).

Lets all be thankful that GM left that legacy code to use a real ethanol sensor even though they have never released a car using the E38 and a flex fuel sensor.

Cheers,
Ross

[GMPX]

I have yet to find anyone that has confirmed that the flex parameters actually enable flex fuel operation. So far I have confirmed that people can shut it off, but I know of no one that has turned it on when it was off by default.
Unfortunately lurking in the ECM is many untapped calibrations that may stop Flex Fuel working even though you tell the ECM it's a FF engine. For example, all the Northstar V8 tunes have no base E85 calibrations set up at all, like GM knew this engine would never go to FlexFuel, so why bother. As a 'loose' rule, if the ECM has some ethanol tables populated (eg, the Stoich table not all one value) then you might get lucky in that all the underlying calibrations that make E85 work maybe populated with functional base values.


Boy, no kidding. I am 50. The 555 was old when I was a kid! I wouldn't use a 555 for anything anymore.

I completely agree about the AVRs. They are awesome. I just wish that documentation from ATMEL was a bit better. I've currently developing with a UC3C0512c.
A few years back I messed around a bit with the Freescale MCF51 series, a great 32bit processor with everything you need and cheap as, like $3 ea. Problem was the dev environment was horrid (for me) as it was focused around C only programming.
Our first hardware (V1) used an AVR Mega8, unfortunately at the time the AVR CAN series was 'pending', we decided to go ahead and design V1 with no CAN ability (this was back in 2004 or so). This was a good decision rather than wait for the new chip as it took Atmel about 4 years to get that AVR CAN chip to market, even then it had bugs. I found AVR studio not too bad to work with as it's not 'C' or 'asm' orientated.

Ira (Fish Tuning) and I often have discussions on AVR's (riveting conversation for anyone listening in).

I wish Freescale would make a small 32 pin Micro with a PowerPC core :shock:

[gmh308]

Boy, no kidding. I am 50. The 555 was old when I was a kid! I wouldn't use a 555 for anything anymore.


555 was new when I was a kid LOFL. So its only a couple years before it got "old" then. Yes why use a 555 when you can use an AVR. I use them as engine simulators and as a "virtual" flex fuel sensor LOL.

[gmh308]

I have yet to find anyone that has confirmed that the flex parameters actually enable flex fuel operation. So far I have confirmed that people can shut it off, but I know of no one that has turned it on when it was off by default. This was certainly true of HP Tuners. Their flex fuel stuff didn't work for turning the function on. EFILive appears to have discovered more of the parameters, however. I am very interested in the answer and might just go ahead and burn up another license to find out.


Didnt I tell you that Sam? :) Didnt make any of the details up! It was all hours of work - WITH - production VFS flex fuel tunes. Have never come across a tune that wouldnt work with the hard sensor selected. But some do not run the sensor fail test and go to the default ethanol content.

[NateD4]

The AVRs are a decent chip to mess with. I'm pretty sure there are other PPC chips available perhaps a ARM series, though my experience setting up the Dev tool chain with Cortex A8s has been less then great.

I don't see why the virtual sensing of E85 content can't be used. You could 'just' as easily add a few CHT and EGT sensors to combine with the O2 sensor to pretty accurately estimate E85 content.

The 3900 V6 I'm messing with has Flex Fuel capability stock. I'm fairly sure the fuel system is different to handle the E85. Only certain elastomers and polymers are compatible with E85. I'm not sure however if straight gas parts are the same part number or not.

E85 has a huge advantage as its published octane rating is well over 105. If memory serves around 110. It should also burn a bit cooler (hence the reason CHT and EGTs with O2 would give you a decent idea what concentration you are running... especially if you throw air mass numbers into it as well... the stochiometry then becomes a somewhat simple thermodynamic calculation which I'm pretty sure the CPU can handle on the fly or at least an external AVR could).

When I priced a new E85 fuel pump from my project car they were around $350-$450 US.

I'm guessing GM is using the same parts for all cars but I could be wrong.

[gmh308]

I don't see why the virtual sensing of E85 content can't be used. You could 'just' as easily add a few CHT and EGT sensors to combine with the O2 sensor to pretty accurately estimate E85 content.

The 3900 V6 I'm messing with has Flex Fuel capability stock. I'm fairly sure the fuel system is different to handle the E85. Only certain elastomers and polymers are compatible with E85. I'm not sure however if straight gas parts are the same part number or not.

It should also burn a bit cooler...

When I priced a new E85 fuel pump from my project car they were around $350-$450 US.

I'm guessing GM is using the same parts for all cars but I could be wrong.

GM "virtual fuel sensor" flex fuel control uses O2 sensors to estimate and adjust for ethanol content. For some reason they have recently started going back to hard sensors. This may be due to the price. Originally (several years ago) they were around $400 as a part. Now they can be found for ~$80. Always driving cost out. Given every platform needs to be calibrated for VFS to work properly, a low cost (GM cost probably $5-$10), a hard sensor is a simpler value proposition.

Have been running E85 for around 3 years now...all on stock fuel system. Steel lines - bare metal exposed, rubber hose, normal Walbro pump. There is no corrosion - even on bare steel. The rubber hose is fine. Injectors are fine. Though I would guess on a car or truck that needs to deliver to a 100,000 mile warranty, is why GM is now using nylon when it is not using coated steel.

The injectors and valve seats are made from a slightly different material to meet durability objectives on flex fuel.

FYI - Intake valve temp is about 30C lower on E85. Approx 130C vs 160C on gas. So nice and cool.

Cheers.

[lt1stang]

Didnt I tell you that Sam? :) Didnt make any of the details up! It was all hours of work - WITH - production VFS flex fuel tunes. Have never come across a tune that wouldnt work with the hard sensor selected. But some do not run the sensor fail test and go to the default ethanol content.

I have a setup (http://forum.efilive.com/showthread.php?18447-I-have-the-oddest-combo-possible) that I wish to be a truly flex fuel compatible automobile but I do not have a E38. I have a gen III 1mb pcm. I wish to run flex fuel and use something to simulate the flex fuel sensor signal or the sensor itself. If this is possible for the E38 Is it possible for the Gen III PCM?

[gmh308]

I have a setup (http://forum.efilive.com/showthread.php?18447-I-have-the-oddest-combo-possible) that I wish to be a truly flex fuel compatible automobile but I do not have a E38. I have a gen III 1mb pcm. I wish to run flex fuel and use something to simulate the flex fuel sensor signal or the sensor itself. If this is possible for the E38 Is it possible for the Gen III PCM?

2006 Silverado 5.3L PCM does Flex Fuel. :)

[lt1stang]

2006 Silverado 5.3L PCM does Flex Fuel. :)
I failed to mention that it is turbocharged and I want to use a COS to run a 2 or 3 bar map.

[Taz]

Fuel composition sensor - GM part # 12570260 - for use with 2002 to 2005 Gen III Flex Fuel engines.


Regards,
Taz

[GMPX]

Holy Rip-off Batman, $313 for a FF sensor!, must be made by Mercedes.
It would be interesting to know what the sensor is that GM Holden are using on the 2010+ Commodore's. Holden's (we are talking E38 here) don't use the virtual sensor algo's, they have a real sensor, I've heard it's part of the fuel pump?

[Taz]

... Holy Rip-off Batman, $313 for a FF sensor! ...

Yes sir ... GM list price is just over $600.


Cheers,
Taz

[GMPX]

Makes sense why GM stuck some software engineers in a dark room to come up with a virtual sensor system if it means they can leave off that expensive sensor for every car. Mind you, GM probably buy them for $20 a pop.

[Taz]

It would be interesting to know what the sensor is that GM Holden are using on the 2010+ Commodore's. Holden's (we are talking E38 here) don't use the virtual sensor algo's, they have a real sensor, I've heard it's part of the fuel pump?

No idea ... no access to Holden schematics or Holden dealer parts inventory database.


Regards,
Taz

[gmh308]

Holy Rip-off Batman, $313 for a FF sensor!, must be made by Mercedes.
It would be interesting to know what the sensor is that GM Holden are using on the 2010+ Commodore's. Holden's (we are talking E38 here) don't use the virtual sensor algo's, they have a real sensor, I've heard it's part of the fuel pump?

Its a couple hundred $ or so in Oz from dealers. From memory available in US for $140. Same output specs as the old gold plated item. Fits inline on regular GM quick connects.

Is there one hidden on your VE? :)

[BLK02WS6]

Great read! Would you guys happen to know how the Gen III PCMs work for E85? I have a non-flex fuel 06 Tahoe and when I compare my OS to the flex fuel 06 Tahoe OS, the only difference seems to be that they have flex fuel enabled. Neither has a flex fuel sensor... If you you know and could provide some input, I have a thread started here: http://forum.efilive.com/showthread.php?18862-Ethanol-questions-converting-non-flex-fuel-to-ethanol

[T2000]

Sorry for the Epic thread dig guys :laugh:

Has anyone actually got this up and running yet?

I planned to give this a try about 12 months ago but got distracted by other projects - oops!

I built the flex fuel emulator (just wrote an arduino sketch) demo here: https://www.facebook.com/photo.php?v=437739162908785

My vehicle is an MY07 L98/6L80E VE Berlina.
Stock OS is the 12612381.
I currently run the 22612381 COS in OL/SD.

The car is running Liquid Injected LPG and I have the COS behaving nicely giving me close to an optimised tune on both PULP and LPG. (would love a VVE for each fuel though ;) - lol )

Missing from 12612381 is the PE table for the alt fuel {B3670}? In the COS I have been using {A9973}

There was mention of a CAX for this table and perhaps a "Lean Cruise" Hack? - I would need the PE table before I can go much further with this...

Many thanks for any advice or suggestions,

Cheers, Chris

[GMPX]

Sorry for the Epic thread dig guys :laugh:
No kidding, the dust is still settling.


The car is running Liquid Injected LPG and I have the COS behaving nicely giving me close to an optimised tune on both PULP and LPG. (would love a VVE for each fuel though ;) - lol )
Ah, no, that won't happen.


Missing from 12612381 is the PE table for the alt fuel {B3670}? In the COS I have been using {A9973}
That is why we added that second A9973 PE table, GM didn't have two in the early E38 OS's.


There was mention of a CAX for this table and perhaps a "Lean Cruise" Hack?
Lean Cruise was never and option (or a hack) on the E38, it was only on the LS1 PCM.

Cheers,
Ross

[T2000]

No kidding, the dust is still settling.


Ah, no, that won't happen.


That is why we added that second A9973 PE table, GM didn't have two in the early E38 OS's.


Lean Cruise was never and option (or a hack) on the E38, it was only on the LS1 PCM.

Cheers,
Ross

Thanks Ross,

I was waiting to see if there were any more responses... I was hoping that the OP might pop in ;)

So my next (obvious) question is which OS I should jump to?

If I can get my hands on a Tech2 (shouldnt be a problem) then I can switch OS.
Which OS supports {B3670} and is compatible with my PCM?

I have had a look at: http://forum.efilive.com/forumdisplay.php?63-V8-V6-L4-E38-E67-amp-E37-ECM-s
So went searching for all OS's > 12612381 and in my "column". Alas no joy on http://www.tunefiledepot.com/index.php?option=com_content&view=article&id=4&Itemid=3&Manufacturer=1&VehicleType=P&Stock=Y
Unfortunately I cant find an OS/Tune to download and check.

I am looking for any tune from:
12612739
12613889
12614088
12614676
12614682
12616478
12617569
12628981
12628988

I am still very keen to pursue this as a fair bit of time went into making the "flexfuel sensor - simulator" and dialing in a vehicle with hand-control of timing will be a significant time and $ saving for anyone taking advantage of this feature.

Cheers, Chris

[Maxwell Power]

Thanks Ross,

I was waiting to see if there were any more responses... I was hoping that the OP might pop in ;)

So my next (obvious) question is which OS I should jump to?

If I can get my hands on a Tech2 (shouldnt be a problem) then I can switch OS.
Which OS supports {B3670} and is compatible with my PCM?

I have had a look at: http://forum.efilive.com/forumdisplay.php?63-V8-V6-L4-E38-E67-amp-E37-ECM-s
So went searching for all OS's > 12612381 and in my "column". Alas no joy on http://www.tunefiledepot.com/index.php?option=com_content&view=article&id=4&Itemid=3&Manufacturer=1&VehicleType=P&Stock=Y
Unfortunately I cant find an OS/Tune to download and check.

I am looking for any tune from:
12612739
12613889
12614088
12614676
12614682
12616478
12617569
12628981
12628988

I am still very keen to pursue this as a fair bit of time went into making the "flexfuel sensor - simulator" and dialing in a vehicle with hand-control of timing will be a significant time and $ saving for anyone taking advantage of this feature.

Cheers, Chris

don't you love the answers you get sometimes?






Anyone know which pin it is on e67 ecm (09 CTSV) that will work with variable flex fuel and not just the on/off feature. Same pin?

[Lsjuan]

Well I guess that's a quorum and even Marcin and Swingtan are interested!

Anyway brought to you via LSXWorks and the capabilities of EFILive (and hopefull their approval..... We thought about "productizing" this idea, but WTF, just share it for everyone to use! Be green, use ethanol, use less gas, and go fast. So read and implement at your own risk :). No claims are made regarding suitability, legality, or even full functionality. Any issues with operation on GM E38's, please contact GM at Renaissance Centre, Detroit Michigan, USA. :)

As you all probably know GM introduced Flex Fuel quite some time back, maybe 7 or 8 years ago. Not quite sure when exactly.

These days their ECM's support flex fuel with virtual fuel sensing (VFS). I.e. they use the O2 sensors, trims and some other (patented) smarts to run learn cycles to determine the ethanol content of the fuel.

This means they avoid having to fit a "hard" ethanol content sensor in the fuel system to measure the ethanol content and input to PCM/ECM. This sensor lists for around $500 so thats a good thing for customers in that failed $500 sensors no longer need replacing. (even if it probably costs GM $50 or less in quantity).

Given that EFILive kindly exposed the ethanol/flex fuel parameters some time ago:

Flex Fuel Option

{B0178} Flex Fuel Option
{B0184} Flex Fuel Sensor Type
{B0185} Flex Fuel Default Percentage
{B0186} Flex Fuel Sensor Diagnostic
{B0187} Flex Fuel Diagnostic Run Time

Which on 08 OS's at least, do work (well VFS seems a little challenging but thats another story), I figured that maybe GM still had support for hard sensors in the OS's and went looking.

To search was laborious, but it appears GM HAS left hard sensor support in there and it does work, at least on 08 Corvette OS (which also does some other trucks and maybe some cars), and may work on other OS's.

So...the magic pin? Pin 40 on the body connector (J1/X1/C1) of the E38 is the fuel composition sensor input. :)

Using EFILive to set the Flex Fuel parameters up:

Flex Fuel Option

{B0178} Flex Fuel Option = Yes
{B0184} Flex Fuel Sensor Type = Actual Sensor
{B0185} Flex Fuel Default Percentage 80% (set it to what you want, 0 is fine to, but remember it has an effect)
{B0186} Flex Fuel Sensor Diagnostic = Enabled
{B0187} Flex Fuel Diagnostic Run Time = 8 Seconds or less if you want.

DTC P0178 to "non emissions" or emissions if you want.
DTC P0179 to "non emissions" or emissions if you want.

MIL P0178 - No MIL (unless you want to observe the ECM failing the sensor when it sees no input frequency - then: MIL ).
MIL P0179 - No MIL (unless you want to observe the ECM failing the sensor when it sees no input frequency - then: MIL ).

(the DTC/MIL settings are suggested and the following probably works ok without this, but it is worth having a fallback ethanol % operating so if your "sensor" unplugs during testing, you know where things will go.)


Point a 100Hz square wave* into that port and the "Flex Fuel Sensor Frequency" PID kindly reflects that it sees 100Hz on the sensor, and also says that the fuel composition is 50% ethanol on the "Ethanol Fuel Percentage" PID.

Vary the square wave up and down from 50Hz to 150Hz and the % E content runs from 0 up to 85%. The actual range the E38 reads is around 20Hz to 190Hz or something like that, but the composition range runs 0 @ 50Hz to 100% @ 150Hz.

Tested this on several different E38 OS's from 06 through to 08 and the pin number and results are consistent.

So that's the overview of how to manually adjust ethanol content on the fly.

If it is purely flex fuel adjustment you are after, using a simple (or complex if you wish) external oscillator (the famous 555 timer chip is one way of generating the needed square wave pretty simply*) enables ethanol content to be adjusted according to your estimate of what is in the tank, or using your LTFT's just adjust the "virtual fuel composition sensor" until the LTFT's are near zero and you are done.

More on the square wave requirement to follow in the notes below*.

Yes to run ethanol in varying amounts it is possible to simply adjust B3671 to reflect your estimated stoich requirement based on E content, but the beauty of the Flex Fuel access that EFILive enables is that it brings the entire flex fuel subsystem into play. This means trims and other things like "intake valve temp" etc. etc. modelling work correctly.

So...on the fly timing and fueling.

To achieve this adjustability is pretty straightforward.

On the fly timing requires several parameters be setup:


1/. B3671 needs to be flatlined! i.e. running premium gas and you know it stoichs at 14.68 then the whole table needs to be set at 14.68. Running E10 then 14.3 or whatever suits your desires.


2/. B5114 Flex Fuel Spark & B5145 Ethanol Spark Multiplier need to be setup. Some OS's have data in there, some have zero's.

As ethanol content is adjusted/changes the ECM interpolates between the main timing tables and the ethanol spark table B5114 factored against B5145.

So B5114 gives you variability of spark. If you want up to 10 degrees of variance then set B5114 to 10deg across the board. +/- 5deg is obtained via selecting the mid point on the adjustment - 100Hz, calling this your baseline timing and then turning up to 150Hz or down to 50Hz.

If you want +/- 10 deg then set B5114 to 20 deg across the board.

So that's on the fly timing.

On the fly fueling:

This requires a little more detail to setup.


1/. ECM needs to be run in Open Loop. (Swingtan's VVE tutorial can assist with that one).

2/. Tables used are:

B0141, B0142, B0143, B0144 (all for auto, one or the other for manual trans').

B0145 (similar to B5145).

With flex fuel running in the ECM, the ethanol content interpolates between B0141 & B0142 for example for open loop fueling based on factoring from B0145.

Additionally PE tables B3618 and B3670 can be used to vary PE mode fueling.
(haven't tested this angle against the WB).

(Sorry Simon, B3670 does not natively appear for O6 OS's, but maybe it is there in the background just waiting to be exposed. :).)

Anyone that has dug into E38's knows of course that unless speed density mode is engaged and VVE/VE based fueling is used with no MAF, that with a MAF in open loop the ECM limits open loop fueling to an EQRatio/lambda of 1.

That can be fixed luckily (but not necessarily easily) with a cax snippet or an EFILive tune tool addition, and if you want you can try adjusting cruise fueling at up to 1.2 lambda/17.5:1 AFR on gas. PM me for details.

Note 1:

The above has been tested on the road, but not to the nth degree, and probably not on your OS. Proceed at your own risk, effort, and hopefully in the end enjoyment and benefit.

Note 2: *

Using Pin 40:

E38's as you probably know use a regulated 5V for most sensors (not all). The fuel sensor input on pin 40 is no different. The 5V needs to be pulled up and down by the square wave oscillator.

Simply injecting a square wave from an oscillator into to pin 40 will in most cases not work. The oscillator ouput needs to drive a transistor which will sink pin 40 towards ground and back up to 5V again as it oscillates. It seems that it is best if the average voltage on the pin is 2.5V (makes sense) and swings from about 0.5 to 4.5 volts.

Electronics whizzes will know how to do this and maybe could post some details and a suggested circuit/components. :)

But in simple terms something like a BC558 transistor for example with the base driven by the oscillator, emitter to ground, and collector to pin 40 does work, but is dependant on the oscillator output level.

A 555 timer IC will support this, and maybe you will find electronics kits that can be modified, either based on 555, or a digital oscillator that runs off a small microprocessor with a display for the frequency.

Note 3:

Wiring up pin 40.

This is covered in detail in the E38 custom OS thread where a tutorial is available for download.

Note 4:

The PID that GM uses to provide sensor frequency is a little messed up. This is a GM PID issue, not an EFILive issue.

If you go to scan this, it appears differently on the V2 BBL to what it does in the scan tool on the PC. The PC Scan tool has the right readout (unless Paul "fixed" up the PID already). The V2 will read the PID but has a different multiplier.

Note 5:

If tune shops want assistance with this, we will consider offering a support service to help set it up. Various forms of currency are negotiable...normal money, beer, bananas, quid pro quo, beer, sea shells, beer.

Note 6:

Only EFILive offers the depth of flex fuel tuning needed to run this capability. Kudos to EFILive for doing this. Am sure they didnt feel visionary at the time, but they were. :)

Note 7:

The above is a little quick and dirty and leaves some details up to the talents of EFILive users who are a smart bunch anyway and more than capable of connecting the dots.

Edit - Note 8: I neglected to mention that the original hard sensor also supposedly reported fuel temperature via the duty cycle of the square wave. Haven't found anything that points to that.

There you go, long yes, all the details...maybe not. But the core info is there, no guarantees, but as mentioned, there has been on the road testing on and off for a while, but not extensive, so there will be further exploration required, but enjoy!


Cheers.

Hey GMH308 sorry to bring this back up from ages ago, tho I am curious as to how you ended building this emulator to fool the ecm I'd love to have some of those, if your not interested in sharing the details of building one any chance you'd like sell a few???

[gmh308]

Wow 46,000+ views - the second most popular non-sticky thread on the forum. :O . I see some folks even built businesses out of the EFILive Flex Fuel information on here.

Anyway, back to the question from LSJuan. From memory I got a "U" build kit - frequency generator - from an electronics shop (Altronics in Australia), and built it. USD$50. A microprocessor controller like a Teensy can also do it, "just" takes some C programming. And circuit design to drive the FF pin.

Trust that makes sense.

[Lsjuan]

Wow 46,000+ views - the second most popular non-sticky thread on the forum. :O . I see some folks even built businesses out of the EFILive Flex Fuel information on here.

Anyway, back to the question from LSJuan. From memory I got a "U" build kit - frequency generator - from an electronics shop (Altronics in Australia), and built it. USD$50. A microprocessor controller like a Teensy can also do it, "just" takes some C programming. And circuit design to drive the FF pin.

Trust that makes sense.

Interesting doesn’t sound to complicated! Is there a write up on how to build this generator? I don’t have any experience on circuit boards and what not.

Did you use a knob to adjust frequency on the fly? Like a dsp5 Switch?

[gmh308]

Interesting doesn’t sound to complicated! Is there a write up on how to build this generator? I don’t have any experience on circuit boards and what not.

Did you use a knob to adjust frequency on the fly? Like a dsp5 Switch?

Something like this probably easiest:

https://www.altronics.com.au/p/q1542-pocket-size-audio-signal-generator/

Anything that will at the very least generate a 50-150Hz square wave.

[joecar]

Made sticky.