NefMoto

Technical => Tuning => Topic started by: cookie44 on August 11, 2016, 04:38:51 PM



Title: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 11, 2016, 04:38:51 PM
hi all, im relatively new to the whole custom mapping so please bear with!

i have an audi a8 2003 4.2 with an ME7.1.1 ecu 4e0.
i cant get the map off of my car yet, but i have a copy of one from the same vehicle to tinker with.

the software that i have is the nefmoto flasher, tunerpro, winols and an ecu grapher and some checksum corrector. ive also done a lot of reading in the s4 forums as they have the same ecu and read the s4 tuning wiki.

my problem is, is that ive run my audi.ori in winols and it states that there are 89 potential maps. great!... what do i do now!? i may also note that i do not have a damos file, xdf or a2l for the ecu. does anyone have any of these? once i do, what do i do after? how do i link the xdf / damos file to the map? basically, what can i expect?

thanks for any help

C


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: k0mpresd on August 11, 2016, 04:53:20 PM
89 maps out of probably around 5k. its a start!


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: nubcake on August 11, 2016, 04:55:40 PM
basically, what can i expect?

Unfortunately, not much.
There's very little (if anything) to be gained by tuning NA car. :(

As far as damos/xdf files - you can start by opening a known documented binary, then try to find patterns and find similar maps in your bin.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 11, 2016, 05:02:58 PM
ha thanks guys, i know there isnt much to gain from the engine, but my main outcome was fuel efficiency.

im not really sure where i would find a documented bin file and how would i know if it was well documented?

C


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: nyet on August 11, 2016, 06:07:09 PM
ha thanks guys, i know there isnt much to gain from the engine, but my main outcome was fuel efficiency.

that isn't happening either. why would audi leave any MPG on the table?


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 11, 2016, 06:34:33 PM
good question... that one i do not now the answer to but, i thought i could give it a go, for example, dropping idle rpms on hot and cold starts, incrementally lower the amount of fuel used when driving (injector timing / fueling) or even cylinders used on idle e.g run 6 on idle 8 when in motion.
i would love to learn exvertything of everything to do with my ecu so i can change and make my own maps, do as i please without messing it up!!

but first i need to find a decent xdf to use on the bin i have

C


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 11, 2016, 06:42:57 PM
this is the bin file i have. this was taken from an a8 4.2 auto... which was taken by a user of this site. this is the bin id like to play with.

c


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: prj on August 12, 2016, 06:48:34 AM
good question... that one i do not now the answer to but, i thought i could give it a go, for example, dropping idle rpms on hot and cold starts, incrementally lower the amount of fuel used when driving (injector timing / fueling) or even cylinders used on idle e.g run 6 on idle 8 when in motion.

You have a lot of reading to do about engines, before touching the ECU.
The things you have written show that you do not have a clue about internal combustion engines.

It is extremely naive of you to think you would do a better job at fuel efficiency than the engineers at the factory.
Before dabbling with the ECU pick up a book or two about ICE internals and processes - you will then understand why what you wrote is complete bs.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: hopsis on August 13, 2016, 12:27:06 AM
All the more experienced people here will tell You that it's pointless to fiddle with a NA engine, especially with one that is relatively good from the factory, as there isn't much room left for tuning (for power). With NA engine pretty much all the improvements are made with ignition advance and rpm. Factory makes the engine so that You can run it to redline all day. If you're willing to ignore these safeguards and add some advance, maybe raise the redline, You can get something out of it. Realistic goals are maybe 10% over stock and even that might be reaching it.

The A8 is a very nice car to have and the 4.2 engine is a very nice motor to put in such a car. It won't be as powerful as a 2.7T but as a luxury sedans engine, the 4.2 is supreme.

As for dropping cylinder's for fuel economy... Impossible. You'd need a totally different cam/valve control.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 13, 2016, 02:07:33 PM
You have a lot of reading to do about engines, before touching the ECU.
The things you have written show that you do not have a clue about internal combustion engines.

It is extremely naive of you to think you would do a better job at fuel efficiency than the engineers at the factory.
Before dabbling with the ECU pick up a book or two about ICE internals and processes - you will then understand why what you wrote is complete bs.


And who the fuck are you? Actually I'm a vehicle technician and have been for the last 7 years. I'm also a university honours graduate in computing I'm very qualified to say what I've said. Unless you can prove to my why I can't do what I want with an ecu then shut up. Your post was inaccurate and irrelevant to the convo.
I never said I was better than the engineers, I'm not too fussed about power loss or how fast it goes, I just want it to be slightly more economical. If you cannot assist in this debate, please see youself out as I don't have time for idiots like you that don't know my background  8)


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: nubcake on August 13, 2016, 02:09:10 PM

And who the fuck are you?
<snip>
please see youself out as I don't have time for idiots like you that don't know my background  8)

I chuckled.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 13, 2016, 02:15:01 PM
All the more experienced people here will tell You that it's pointless to fiddle with a NA engine, especially with one that is relatively good from the factory, as there isn't much room left for tuning (for power). With NA engine pretty much all the improvements are made with ignition advance and rpm. Factory makes the engine so that You can run it to redline all day. If you're willing to ignore these safeguards and add some advance, maybe raise the redline, You can get something out of it. Realistic goals are maybe 10% over stock and even that might be reaching it.

The A8 is a very nice car to have and the 4.2 engine is a very nice motor to put in such a car. It won't be as powerful as a 2.7T but as a luxury sedans engine, the 4.2 is supreme.

As for dropping cylinder's for fuel economy... Impossible. You'd need a totally different cam/valve control.

Thank you, a relevant statement. I know with it being na it hasn't got much potential other than fitting a supercgarger, which I may as well have got the s8 instead. But it's not the power I'm looking for. I don't mind losing a few hp for extra few mpg


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: nyet on August 13, 2016, 02:26:04 PM
I don't mind losing a few hp for extra few mpg

Answer: don't step on the gas as hard. Seriously.

It isn't clear you're listening :/

There is zero reason for the manufacturer to leave even a little MPG on the table, AND you have a V8. It will never get decent MPG.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: nubcake on August 13, 2016, 02:28:43 PM
Seriously, if you want fuel economy on this exact car - get LPG installed, if it's available where you are. Probably makes much more sense than trying to outsmart Audi engineers.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: prj on August 13, 2016, 02:45:55 PM
And who the fuck are you?
Someone who calibrates ECU's for a living.
Quote
Actually I'm a vehicle technician and have been for the last 7 years. I'm also a university honours graduate in computing I'm very qualified to say what I've said. Unless you can prove to my why I can't do what I want with an ecu then shut up. Your post was inaccurate and irrelevant to the convo.
I never said I was better than the engineers, I'm not too fussed about power loss or how fast it goes, I just want it to be slightly more economical. If you cannot assist in this debate, please see youself out as I don't have time for idiots like you that don't know my background  8)
So you are a wrench - does that make you qualified to say something about how ICE-s work? No.
Computing? No.
for example, dropping idle rpms on hot and cold starts
Idle RPM on hot start is a compromise between vibration and fuel efficiency. Also, Idle RPM is nearly irrelevant to fuel consumption unless your car spends the majority of time idling.
If the RPM is pushed below what it effectively can run, fuel consumption increases.
Quote
incrementally lower the amount of fuel used when driving (injector timing / fueling)
This means leaning out the mixture. The engine runs closed loop lambda 1 when cruising.
Putting it in open loop, then leaning this out significantly will lose power and increase fuel consumption.
Quote
or even cylinders used on idle e.g run 6 on idle 8 when in motion.
This is the main reason why I called you out. The engine will use a lot more fuel this way. Anyone who knows how engines work in the slightest knows this.
But not you.
Unless you manage to stop the intake and exhaust valves from opening, thus creating an air spring, all you do by cutting fuel to the cylinder is increase fuel consumption.
Quote
i would love to learn exvertything of everything to do with my ecu so i can change and make my own maps, do as i please without messing it up!!
but first i need to find a decent xdf to use on the bin i have
If you had 1/10th of the credentials you claim to have, you would already have built this xdf from the information that is found on this forum.

Good luck.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: prj on August 13, 2016, 02:48:58 PM
All the more experienced people here will tell You that it's pointless to fiddle with a NA engine, especially with one that is relatively good from the factory, as there isn't much room left for tuning (for power). With NA engine pretty much all the improvements are made with ignition advance and rpm. Factory makes the engine so that You can run it to redline all day. If you're willing to ignore these safeguards and add some advance, maybe raise the redline, You can get something out of it. Realistic goals are maybe 10% over stock and even that might be reaching it.
These engines are nearly perfectly calibrated for 98 RON (93 in the states).
Having tuned one of these on the dyno I can tell you that getting 2-3% out of it, you're doing a good job.
If you just increase advance, it will knock, and pull even more advance out than you added, resulting in loss of power. It already runs lambda 0.9 flat. Adding more fuel also makes less torque in most places.
There is very little that can be done on these engines - the stock cal is very good.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 13, 2016, 04:54:27 PM
If you had 1/10th of the credentials you claim to have, you would already have built this xdf from the information that is found on this forum.

You miss the part where I said I was "new to the ecu mapping thing"? When it comes to computers I'm not stupid. I know how to program, I know how to read code, I know how to do most things with vehicles. All I need to do is be pointed in the right direction. As I've stated, I cannot find this information, that's why I'm here asking about it, I don't know what I'm looking for, it's got nothing to do with credentials at all. If you haven't done it before now can you be expected to find something if you don't know what it is your looking for?? Doesn't make much sense of I'm honest. If I find bits of information I'll build one myself because it looks like no body has a clue or they just point out irelevant things


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: nyet on August 13, 2016, 05:13:59 PM
What do you think an xdf is? What is preventing you from starting from a known bin and xdf and comparing? Or, if you are familiar with computers, using IDA or similar tool to start disassembling?


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: prj on August 13, 2016, 06:04:28 PM
I don't think I have missed anything tbh.
Read your own chest-bang response and learn some manners if you want to get anywhere.

As for your credentials - did they include using google search? Because there are lots of defs for various flavours of 4.2 V8 on this forum.
Hardly rocket science to take one of those and find the relevant places in your binary - or is it?

Not that it will help you much, since none of the things you listed engine wise are going to do anything. About the only thing you can do is change the lambda switch point, which is a single value on narrowband ecu's. D3 should be dual wideband - in this case it is slightly more involved.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 14, 2016, 12:37:00 AM
What do you think an xdf is? What is preventing you from starting from a known bin and xdf and comparing? Or, if you are familiar with computers, using IDA or similar tool to start disassembling?

An xdf tells you where the maps are and what each map does. And I couldn't find a known bin which was why I've been asking for one or an xdf of my ecu. I have been looking for the last week or so spending hours looking around but couldn't find much. I could disassemble it, I didn't know I had to. So if was to do that what would It do?
I do have an xdf but it's for an 8D. Sort of worked but with it being different I don't think it matches up right.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 14, 2016, 12:43:03 AM
As for your credentials - did they include using google search? Because there are lots of defs for various flavours of 4.2 V8 on this forum.
Hardly rocket science to take one of those and find the relevant places in your binary - or is it?

If you think you can find me a def file that will work with my ecu then you find one, because I can't. I've been looking for the last week or so looking for one, I don't fully know what I'm looking for so. That's why I'm here?? Are you not getting this at all??
All I've done is asked for an xdf file or some assistance in finding one or making my own and all you've done is told me how naive I am and how I've got no credentials. What kind of inspiration is that?  


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: Mikhail on August 14, 2016, 05:52:54 AM
If you think you can find me a def file that will work with my ecu then you find one, because I can't. I've been looking for the last week or so looking for one, I don't fully know what I'm looking for so. That's why I'm here?? Are you not getting this at all??
All I've done is asked for an xdf file or some assistance in finding one or making my own and all you've done is told me how naive I am and how I've got no credentials. What kind of inspiration is that? 
I have used winols 2.24 (German language) to (start) figure out the def of my car. Just open your .bin project and a defined project you think is close to you. Then roll the defined bin say MLHFM (look the address to the left side where the definition section is) and notice the look of the bars besides hex code. Now roll yours bin at the same address than the defined bin and look around a wide range to recognize same look bars. Now take a programmer calculator and calculate the offset (hex) of address difference of these two bins when you have found the same looking bars. Now at winols select at the drop-down menu "Ansicht" at the up left and to that menu select "Fenster_koppeln". At the opened popup press OK. Now at the section which appeared between the bins put the offset you calculated to the box "Offset". Now At the middle use the + and - buttons to sift bin to each other to get them aligned. Now when you think that your map is found, press the "Kopieren" to the second right button. Now select at the popup the lowest radio button and select the box above the OK button and press OK. Now look the map definition you copied and if it seems to be a bit off, then open the map to it's own popup and adjust the map address to get it aligned.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: _nameless on August 14, 2016, 05:54:41 AM
If you think you can find me a def file that will work with my ecu then you find one, because I can't. I've been looking for the last week or so looking for one, I don't fully know what I'm looking for so. That's why I'm here?? Are you not getting this at all??
All I've done is asked for an xdf file or some assistance in finding one or making my own and all you've done is told me how naive I am and how I've got no credentials. What kind of inspiration is that?  
You should really watch how you talk to people, prj is one of the most advanced members on the forum and has contributed a lot. If you're smart enough to listen to what he has to say and take some constructive criticism most likely you'd have gotten useable info instead of trying to be an Internet tough guy. What you fail to realize is all of the info on this forum is a "trickle down effect" the knolage starts with a select few members and then over time gets distributed. With that said you just stepped on the toes of a few that could have helped you. So good luck I'm sure you'll end up in the black hole like the other 99% of new members


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 14, 2016, 09:19:11 AM
You should really watch how you talk to people, prj is one of the most advanced members on the forum and has contributed a lot. If you're smart enough to listen to what he has to say and take some constructive criticism most likely you'd have gotten useable info instead of trying to be an Internet tough guy. What you fail to realize is all of the info on this forum is a "trickle down effect" the knolage starts with a select few members and then over time gets distributed. With that said you just stepped on the toes of a few that could have helped you. So good luck I'm sure you'll end up in the black hole like the other 99% of new members

Maybe so but telling me what I'm saying is utter b.s. is out of line, I don't even know him. He may be smart fair enough I'm not disputing that. It's like he can say what he wants to any member and others defend him just because he's smart. Wether your smart or not, if your going to help me then I would appreciate that, but if your going to come into my thread and start telling me what I'm saying is b.s. and I should watch what I say then do it somewhere else. If you don't have anything to say, don't say it at all.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 14, 2016, 09:22:12 AM
I have used winols 2.24 (German language) to (start) figure out the def of my car. Just open your .bin project and a defined project you think is close to you. Then roll the defined bin say MLHFM (look the address to the left side where the definition section is) and notice the look of the bars besides hex code. Now roll yours bin at the same address than the defined bin and look around a wide range to recognize same look bars. Now take a programmer calculator and calculate the offset (hex) of address difference of these two bins when you have found the same looking bars. Now at winols select at the drop-down menu "Ansicht" at the up left and to that menu select "Fenster_koppeln". At the opened popup press OK. Now at the section which appeared between the bins put the offset you calculated to the box "Offset". Now At the middle use the + and - buttons to sift bin to each other to get them aligned. Now when you think that your map is found, press the "Kopieren" to the second right button. Now select at the popup the lowest radio button and select the box above the OK button and press OK. Now look the map definition you copied and if it seems to be a bit off, then open the map to it's own popup and adjust the map address to get it aligned.

Thanks Mikhail, I'll try to look for one. How do I know if it's defined?

C


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: k0mpresd on August 14, 2016, 09:25:08 AM
Maybe so but telling me what I'm saying is utter b.s. is out of line, I don't even know him. He may be smart fair enough I'm not disputing that. It's like he can say what he wants to any member and others defend him just because he's smart. Wether your smart or not, if your going to help me then I would appreciate that, but if your going to come into my thread and start telling me what I'm saying is b.s. and I should watch what I say then do it somewhere else. If you don't have anything to say, don't say it at all.

*Whether
*you're
*you're
*you're


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 14, 2016, 09:26:43 AM
*Whether
*you're
*you're
*you're

Thank you for your corrections. Anything else?


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: k0mpresd on August 14, 2016, 09:32:03 AM
Thank you for your corrections. Anything else?

that's the only post i paid attention to honestly. i can go back through your others if you'd like?


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 14, 2016, 09:33:12 AM
that's the only post i paid attention to honestly. i can go back through your others if you'd like?

I'd rather you didnt, there's a lot of text


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: prj on August 14, 2016, 10:13:17 AM
Maybe so but telling me what I'm saying is utter b.s. is out of line, I don't even know him. He may be smart fair enough I'm not disputing that. It's like he can say what he wants to any member and others defend him just because he's smart. Wether your smart or not, if your going to help me then I would appreciate that, but if your going to come into my thread and start telling me what I'm saying is b.s. and I should watch what I say then do it somewhere else. If you don't have anything to say, don't say it at all.
We're not in kindergarten. I don't need to sugarcoat your bullshit.
You have plenty of info in this thread to get started. Much more than those of us who did this years ago.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: nyet on August 14, 2016, 10:30:30 AM
if your going to come into my thread and start telling me what I'm saying is b.s. and I should watch what I say then do it somewhere else

Sorry, that isn't how the world works. If you post stuff that is wrong, you'll get responses, if only to make sure others don't get misinformation.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 14, 2016, 01:10:39 PM
I understand that, I have no problem with others correct me and say sorry mate but that won't work, maybe you could do this in stead. Not "what you've said is utter b.s".


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: vwaudiguy on August 14, 2016, 09:38:54 PM
Instead is one word. J/k


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: Mikhail on August 14, 2016, 10:58:14 PM
Thanks Mikhail, I'll try to look for one. How do I know if it's defined?

C
Just open the map to it's own popup and look the values that does they make sense. If part of the map axis values or the map table values look strange, then try change the map address (klick mouse right button above the map popup to open a menu, then select the bottom selection to that menu). The map axis values may be at the beginning of the map (at the bin hex code) or they may be elsewhere.

Forgot to say, that to copy the definition, you have to select the map at the defined bin by mouse left button.

At this point when you have copied some definition to your project, the definition is in your project, just save it and look where winols saves it.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: bitmap on August 16, 2016, 08:02:33 AM
There is zero reason for the manufacturer to leave even a little MPG on the table, AND you have a V8. It will never get decent MPG.
Actually, there is - emissions.
I don't know about petrol engines since I'm yet to mess with one with FE in mind but as for diesels and especially turbocharged diesels, there is quite a lot to be gained if they are calibrated for EURO3 or higher.
I myself achieved 14% better FE on EURO4 2.0 TDI just by messing with the calibration in part load area.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 16, 2016, 03:10:27 PM
This is great news :) I'm yet to do more work on the code I have as I haven't done anything for a few days (work) but I'll get my code sorted so it's in a readable condition!


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 16, 2016, 03:11:11 PM
Just open the map to it's own popup and look the values that does they make sense. If part of the map axis values or the map table values look strange, then try change the map address (klick mouse right button above the map popup to open a menu, then select the bottom selection to that menu). The map axis values may be at the beginning of the map (at the bin hex code) or they may be elsewhere.

Forgot to say, that to copy the definition, you have to select the map at the defined bin by mouse left button.

At this point when you have copied some definition to your project, the definition is in your project, just save it and look where winols saves it.

Thanks for that mate I'll get on it


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: seishuku on August 17, 2016, 10:10:57 AM
This is great news :) I'm yet to do more work on the code I have as I haven't done anything for a few days (work) but I'll get my code sorted so it's in a readable condition!
Yup, they don't get very aggressive with fuel cut on overrun, have to keep the cats hot.
Cutting back light load to near 15:1, and cut fuel completely on overrun will yield a significant MPG increase.

Obviously emissions will increase as well, mainly NOx if I recall.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 17, 2016, 11:51:10 AM
Yup, they don't get very aggressive with fuel cut on overrun, have to keep the cats hot.
Cutting back light load to near 15:1, and cut fuel completely on overrun will yield a significant MPG increase.

Obviously emissions will increase as well, mainly NOx if I recall.

With a petrol then thatshouldnt be much of a problem with it not having to heat up cats? With it being not a diesel

C


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: seishuku on August 17, 2016, 04:24:05 PM
With a petrol then thatshouldnt be much of a problem with it not having to heat up cats? With it being not a diesel

C
Depends on the converter and it's optimum operating temperature, or no problem at all if they've been removed! ;D

Or it could be they're injecting extra fuel to keep NOx production lower, so the cats don't have to work as much.
Minimal NOx production usually happens around 14.3:1, either way, the crappy MPG ratings are usually emissions related, to keep catalytic converters happy and NOx low (also CO and HC to an extent).


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: cookie44 on August 18, 2016, 05:18:45 AM
Depends on the converter and it's optimum operating temperature, or no problem at all if they've been removed ;D

You think I could remove my torque converter?? That would be great! Although it means swapping the big itself for a msnual one and fitting clutch pedals and alsorts of rubbish. I would like to have a manual conversion. That would save lots of fuel. But it does have a lock up clutch but only at at a pace. Maybe I'll get the tcm remapped to have it engage sooner and have ecu done to lower consumption a touch


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: prj on August 18, 2016, 01:44:33 PM
Actually, there is - emissions.
I don't know about petrol engines since I'm yet to mess with one with FE in mind but as for diesels and especially turbocharged diesels, there is quite a lot to be gained if they are calibrated for EURO3 or higher.
I myself achieved 14% better FE on EURO4 2.0 TDI just by messing with the calibration in part load area.
This is not a diesel with retarded soi for NoX. On Gasoline the only thing you can do is very slightly lean out the target AFR, but this has to be done as an ASM hack, which the OP will never get done. The fuel efficiency difference is max 1%, if that. I will also challenge you any time on that 14% claim. You are not going to make 14% more fuel efficiency by closing the EGR and bumping SOI in the "loft". Not even close. On 1-2 spots on the map maybe, but your car spends <1% of time in those spots.

Yup, they don't get very aggressive with fuel cut on overrun, have to keep the cats hot.

Cutting back light load to near 15:1, and cut fuel completely on overrun will yield a significant MPG increase.

Obviously emissions will increase as well, mainly NOx if I recall.
I wonder where these myths come from?
Have you tuned an Audi A8 D3? You can not have, because none of what you say make sense.

Dumping fuel on overrun:
1. Increases consumption
2. Increases emissions
3. Will melt the cat if the cat is not specially designed for it.

Guess what - this car does not do this. Fuel is cut completely and resumed at RPM X. Very easy to see if you ever drove any of these cars with a wideband. But let me guess, you never have.

The only time some cars are slightly liberal with cutting fuel is to make exhaust noise on some newer "performance oriented" cars. The Renault Megane RS is a good example, then again it runs a metal cat for this very reason.
Leaning from 14.7 to 15.0 is 2% leaner. You will also make less power. The net gain in fuel efficiency is <1%. Never mind the fact that you have to do ASM hacks to get the ECU to request a leaner ratio than 1.0 and stay in closed loop. Not to mention that you will fail a sniffer emission test if you come in with a car that holds 1.02 lambda in closed loop - but this depends whether they do this test in your country.

Not worth it. Not even close. Calling <1% fuel differences "significant" - please...


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: seishuku on August 18, 2016, 02:19:12 PM
I said cut fuel on overrun, not dump... Also leaning out light loads, not in general.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: nyet on August 18, 2016, 02:19:57 PM
Leaning from 14.7 to 15.0 is 2% leaner. You will also make less power.
x1000000

This is what I don't get.

If you want to save gas, don't hit the gas pedal as hard. Or restrict KFPED to 50% max. It really is that simple.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: prj on August 18, 2016, 02:23:39 PM
I said cut fuel on overrun, not dump... Also leaning out light loads, not in general.
It is exactly the same as you said. The process you described does not exist on this car. No cars actually increase fueling on overrun, the ones that pop and bang simply do not cut all the injectors all the time and use a very late ignition angle.
On this particular engine the cylinders are cut at the highest possible speed that does not cause a jerk and are phased in the same way.
They are cut completely. The injectors are fully closed.
Again, it is not possible to make it run above lambda 1 in closed loop without modifying the code in the ECU, especially if you want to do it only on some rpm's. Even then, as I said, the difference would be <1%.

I have tuned this very engine. I have put it in a different chassis. I have strapped a supercharger to it, and I have tuned the said supercharger to perfection.
I have something you do not - I have actual experience with this very engine, and this is why I am replying to this topic in the first place. Your theorycraft is going nowhere, because you could not be more wrong. You have no experience with this engine and you have very little experience calibrating VAG gasoline control units, because what you said is simply the exact opposite of what happens in reality.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: seishuku on August 19, 2016, 10:19:47 AM
Perhaps the terminology is different, coming from Megasquirt and other aftermarket engine controls, they refer to overrun as occuring on decel (foot off pedal).
Also I wasn't saying lean out in the power band (where you would lose power), I mean at cruising.

No, I dont have exact experience with this exact engine, I did dabble a bit with my AWN 4.2 when I had it... Otherwise, most of my tuning comes from Nissan 4 cylinder engines.

At any rate, it's no reason to get bent out of shape about, chill.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: bitmap on August 20, 2016, 11:27:55 PM
This is not a diesel with retarded soi for NoX. On Gasoline the only thing you can do is very slightly lean out the target AFR, but this has to be done as an ASM hack, which the OP will never get done. The fuel efficiency difference is max 1%, if that. I will also challenge you any time on that 14% claim. You are not going to make 14% more fuel efficiency by closing the EGR and bumping SOI in the "loft". Not even close. On 1-2 spots on the map maybe, but your car spends <1% of time in those spots.
You can challenge me all you want but my numbers don't lie :)
I can regularly achieve 60MPG(US) tanks without really trying and once I tried really hard and got 69MPG tank with my TDI which also develops 205hp and 450Nm when floored.

My car is extensively modified for maximum efficiency and those 14% I mentioned came from just ECU tuning and bulk of the modificaion lies in the boost control not SOI or EGR.
Only thing that stayed stock in the boost department were PID parameters and everything else I had to write from scratch. EGR and SOI control were a walk in the park after that :)


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: nubcake on August 21, 2016, 02:30:48 AM
You can challenge me all you want but my numbers don't lie :)
I can regularly achieve 60MPG(US) tanks without really trying and once I tried really hard and got 69MPG tank with my TDI which also develops 205hp and 450Nm when floored.

My car is extensively modified for maximum efficiency and those 14% I mentioned came from just ECU tuning and bulk of the modificaion lies in the boost control not SOI or EGR.
Only thing that stayed stock in the boost department were PID parameters and everything else I had to write from scratch. EGR and SOI control were a walk in the park after that :)

You do realize that we're talking about petrol NA engine and you're quoting TDI differences, do you?


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: bitmap on August 21, 2016, 03:43:56 AM
Yes I know I'm off topic.
prj "challenged" the possibility of achieving 14% better FE on my stinky TDI just by recalibrating ECU so I just wanted to clarify how I did "the impossible".

Also, you lot clearly don't understand how part load engine behaviour is supposed to work saying that leaning out part throttle lambda won't effect fuel economy much because engine will make less power as a result of that.

In a cruising situation, on a throttled engine you actually want to make least amount of power for a given throttle opening so that when not much power is required, throttle is open as much as possible, therefore intake manifold pressure is as close to atmospheric as possible, therefore engine is running more efficiently while making less power than it possibly could if tuned "properly".

This stuff is not very intuitive so I understand why a lot of people might think that factory tune can't be improved upon in this area but when emission regulations are involved, there ALWAYS is a room for improvement. Especially if the engine has continuously variable valve timing and/or external EGR system (which I don't know if this V8 has any of that).


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: vwaudiguy on August 21, 2016, 12:27:35 PM
Yes I know I'm off topic.
prj "challenged" the possibility of achieving 14% better FE on my stinky TDI just by recalibrating ECU so I just wanted to clarify how I did "the impossible".

Also, you lot clearly don't understand how part load engine behaviour is supposed to work saying that leaning out part throttle lambda won't effect fuel economy much because engine will make less power as a result of that.

In a cruising situation, on a throttled engine you actually want to make least amount of power for a given throttle opening so that when not much power is required, throttle is open as much as possible, therefore intake manifold pressure is as close to atmospheric as possible, therefore engine is running more efficiently while making less power than it possibly could if tuned "properly".

This stuff is not very intuitive so I understand why a lot of people might think that factory tune can't be improved upon in this area but when emission regulations are involved, there ALWAYS is a room for improvement. Especially if the engine has continuously variable valve timing and/or external EGR system (which I don't know if this V8 has any of that).

Wow. Just wow.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: k0mpresd on August 21, 2016, 04:08:19 PM
Wow. Just wow.

you have to appreciate the confidence in that post.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: hopsis on August 21, 2016, 11:21:33 PM
Yeah, I have four of these N/A petrol V8 engines so You can understand fuel efficiency means the world to me. I'm getting the ebay resistor chip for my MAF sensor. Seller tells me it will reduce fuel consumption by 10%. I went and bought ten so that should amount to 100% of fuel savings.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: bitmap on August 21, 2016, 11:44:54 PM
It's Ok guys, I'm used to people thinking I'm a complete idiot.
I even had a big car magazine in my country test my car and they verified all my claims but people still think I'm full of shit and that I paid them off to write that article even though I'm not trying to sell anything :D


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: nyet on August 21, 2016, 11:55:12 PM
Hint: the 4.2 isn't a TDI


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: bitmap on August 22, 2016, 01:09:37 AM
I know, no hints necessary.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: prj on August 22, 2016, 02:36:18 AM
In a cruising situation, on a throttled engine you actually want to make least amount of power for a given throttle opening so that when not much power is required, throttle is open as much as possible, therefore intake manifold pressure is as close to atmospheric as possible, therefore engine is running more efficiently while making less power than it possibly could if tuned "properly".
I think you need to read a book about internal combustion engines. This made me lol.

As for TDI, you would need to show fuel/hp at each operating point on dyno, otherwise it is just talk.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: turbojohan on August 22, 2016, 02:53:26 AM
You can get some better fuel economy on better fuel and bit of mapping, but better fuel will cost more...
Better try get economy from tires, tire pressure and allignment... or buy a diesel :-)

Johan


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: prj on August 22, 2016, 02:57:02 AM
You can get some better fuel economy on better fuel and bit of mapping, but better fuel will cost more...
Better try get economy from tires, tire pressure and allignment... or buy a diesel :-)

Johan

Don't forget the driver's right foot :P


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: turbojohan on August 22, 2016, 03:01:55 AM
that's of course the biggest gain  ;D ;D


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: hopsis on August 22, 2016, 11:21:16 PM
Can someone please point out how tuning a turbocharged diesel engine is relevant to mapping a BFM engine? All this is borderline interesting but in the end completely pointless.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: monkey-leader on January 22, 2021, 03:28:07 PM
I love trying to learn things on the internet. Somebody asks questions and instantly gets shat on by some clown that thinks they are an Audi engineer. Proceeds to ruin the thread by making it extremely toxic.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: fjgarvi10 on March 07, 2021, 04:20:55 PM
Hello, I refloat the issue, I also need a2l or xdf for this vehicle, not to lower the consumption precisely haha, if not to remove Vmax, since here in Spain it is limited to 250 km. If someone could give me a hand it would be appreciated. I can pass the full ecu backup!
THANK YOU.


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: Toys-n-joys on September 03, 2022, 07:25:32 PM
It is exactly the same as you said. The process you described does not exist on this car. No cars actually increase fueling on overrun, the ones that pop and bang simply do not cut all the injectors all the time and use a very late ignition angle.
On this particular engine the cylinders are cut at the highest possible speed that does not cause a jerk and are phased in the same way.
They are cut completely. The injectors are fully closed.
Again, it is not possible to make it run above lambda 1 in closed loop without modifying the code in the ECU, especially if you want to do it only on some rpm's. Even then, as I said, the difference would be <1%.

I have tuned this very engine. I have put it in a different chassis. I have strapped a supercharger to it, and I have tuned the said supercharger to perfection.
I have something you do not - I have actual experience with this very engine, and this is why I am replying to this topic in the first place. Your theorycraft is going nowhere, because you could not be more wrong. You have no experience with this engine and you have very little experience calibrating VAG gasoline control units, because what you said is simply the exact opposite of what happens in reality.


i picked up a procharger d1sc kit for my 4.2 bfm engine in a d3 a8l. plan on slower s/c rpm around 4in or 4.5in pulley on the d1sc. should be good for 400whp+- with a intercooler and meth injection. is there a easy way to add a map sensor with the original ecu? or would just the maf sensor be plenty speed density tuned?

@prj what supercharger did you use? also what power were you able to make from a oem bfm engine with the supercharger? if you still have some pics post them up id like to see them and hear your experience


Title: Re: audi a8 4.2 bfm ME7.1.1 custom mapping
Post by: prj on September 04, 2022, 01:25:46 AM
No pressure sensor, don't need it.
But good luck getting it to run right, it was a proper pain in the ass.

If you install WMI you won't need an intercooler.

I tuned a PES kit.