ECU OEM adaptive learning, not my cup of tea.

[Candide13]

Originally Posted by grantmax

^ What he said.

I have to rip for a day or two in order to retrain the ECU. By then, I'm back in traffic and don't need Captain Insano.

The net-net is that I rarely have the right vehicular attitude for the prevailing road conditions. Le sigh.

Interesting, I am usually stuck in traffic so when I do make it out to the open road or the track, I always assume that I am shaking out the cobwebs in my own driving mind, and getting used to push the pedal more, revving above 4K etc, and consequently I feel that the car is getting crisper. Perhaps some of that is due to the ECU adaptation. But its a very subjective feeling.

Anyhow, if it is that obvious to some then it would be great to have some objective input, (e.g. acceleration numbers from 30-80 mph) to quantify this effect.

[to///m]

I have always noticed this behavior with my M3 and have just thought it was me! WOW, I have always said that I feel like the harder I drive my car, the better it runs... and if I drive it conservatively, it feels sluggish when I want to get on it! I figured it was in my head.

So some people have said you can reset this? May I ask how and from who?

Also, does the E46 M3 have the same adaptive ECU?

[Helmsman]

Originally Posted by grantmax

This. I can absolutely confirm the negative effect of driver adaptions. I get punished because I don't want to go apesh*t on the 10 at 8:07 a.m.

Due to what @edward has explained, I tend to reset my adaptions every few months. After each reset, my car drives like Edward's.

This part our of ECU really bothers me. Of course, when I get a chance to push the car, consistently, the ECU figures it out and gives me more. It is the most frustrating when I can't make a certain move because I don't have @edward's engine response at the ready.

Grantmax, so you reset by disconnecting the battery or what?

Thanks

[nthretourNAFTW]

Originally Posted by sello

This all kinda makes sense! Wonder if this is why some stock m3's dyno lower. Cuz there not in beast mode?

Yes, drive the car like an accord for 1 week and dyno it, the results will be disapointing and below specs. Track the car in the next week and do another dyno, there will be big improvement. Also monitor the air-fuel ratio in both cases you will see the ECU running too rich in the first case. Incidentally AFR showing too rich mix correlating with poor dyno results has already been observed. But nobody realized it is caused by bad ECU adaptation software.


This also says that the existing dyno run database has little representative value. The only way to take those dyno consistently is to reset the adaptation prior. But that's not ideal either, you'd want to let the adaption extract the best performance possible instead it can screw your results. Thanks bmw. The only way to get the best dyno is after a day at the racetrack.

[nthretourNAFTW]

Originally Posted by to///m

I have always noticed this behavior with my M3 and have just thought it was me! WOW, I have always said that I feel like the harder I drive my car, the better it runs... and if I drive it conservatively, it feels sluggish when I want to get on it! I figured it was in my head.

So some people have said you can reset this? May I ask how and from who?

Also, does the E46 M3 have the same adaptive ECU?

Yes, this is exactly what's going on and it's caused by bad ECU software design !

You cannot reset the ECU back to default values yourself you need a dealer level tool like ModIC or GT1. You will see the option in the menu to reset adaptation. Only ODB I system can be reset by disconnecting the battery, not ODB II.
Incidentally i had that information already in the OP of the thread

[nthretourNAFTW]

Originally Posted by Candide13

Anyhow, if it is that obvious to some then it would be great to have some objective input, (e.g. acceleration numbers from 30-80 mph) to quantify this effect.

Drive the car like a nannie for one week, dyno it, track it a couple times the next week and do another dyno. The results will be night and day. There is your objective input.

[grantmax]

Originally Posted by to///m

I have always noticed this behavior with my M3 and have just thought it was me! WOW, I have always said that I feel like the harder I drive my car, the better it runs... and if I drive it conservatively, it feels sluggish when I want to get on it! I figured it was in my head.

So some people have said you can reset this? May I ask how and from who?

Also, does the E46 M3 have the same adaptive ECU?

I read some interesting information about this "effect" a few months back. One of the main causes of "sad mode" is the ECU attempting to determine how much throttle the driver really wants.

Each time you get on it and back off it thinks, "oh, he was just having a quick laugh, good thing we didn't get overexcited and really wind up." This trains the ECU to doubt your throttle request. Enter "sad mode". I find that consistent revving and unwavering throttle input is the quickest way to slap the ECU in the hindquarters. It wakes up after a few quick runs through the gears as it thinks, "ok ok, now he wants everything I've got."

I will defend this to the death as I have personally felt the difference is character between my car and @Edward's. While I have more power and rev quicker, his throttle response and eagerness cannot be denied. Case in point, when my car was updated to 140e (or whatever the latest bmw map is), the dealer reset my adaptations. For the next few days, I discussed with Edward at length how my car felt like his. Naturally, this went away after a few commutes to Downtown LA.

Re: resetting adaptions - I have the Evolve tune and software which allows me to do this. I also think (but am unsure, please confirm) that the BMWLogger program offers this. And of course, the dealer can do this for you. To use the programs at home, you'll need a $30 cable from Amazon but it's a simple process with little downside.

[tubedreamer]

Originally Posted by nthretourNAFTW

The ECU has a bunch of tracking functions that it applies to the installed factory software. The code in itself is the functioning brain of the ECU and cannot be rewritten. It's doing constant adapting depending on feedback from different sensors (e.g. Oxygen, Mass Air, etc...), which affect any number of "adaptations".

The way adaptation works is as follow. Lets say that you're cruising down the road as normal, the car reads off of a predefined table of values making minor changes as need based on the feedback of the sensors. Those minor changes are called "trims". There are two types of trims STFT (Short Term Fuel Trim) and LTFT (Long Term Fuel Trim).
After a number of drive cycles the ECU decides that it runs better with that trimming let's say adding extra fuel and will move the STFT to an LTFT. After another number of drive cycles the LTFT will actually replace the value written in the predefined table.

Another separate indication of adaptive ECU is after long highway drives returning to local mixed driving the ECU will continue to follow a different AFR mix for a day or two after the highway trip giving better mpg. Then will eventually go richer mix with poorer mpg. I reset the onboard mpg counter after the highway drive so i know it's not a trailing average in the mpg counter.

Are you monitoring this behavior through the odbii port?


Wouldn't it be cool if the ecu could be open sourced for enthusiasts? One can only dream. Don't think it could ever happen for a car.

[Edward]

Originally Posted by Flying Ace

wouldn't you think if grantmax did drive like a putssy, over time the software would learn to be more "aggressive" like your car?

Precisely. If grantmax weren't preoccupied with listening to Sting and pondering what tree bark was made out of, he could be a bit more focused on properly training his car computer. But to no avail-his car wants to be a dog more than his actual new dog.

[KFN]

A while back I did some work for a company that makes ECU diagnostic equipment for most of the big brands. It was explained to me that OBD II was mandated solely as a way of controlling emissions (since the architecture is already there, it's used for monitoring everything else too). By adapting engine settings to be most efficient relative to how the car is driven, performance is most definitely affected. I haven't noticed it yet with the M3, but my M Coupe was much quicker and more responsive on the way home from the track.

I asked if they could program my car for max power all the time and they said yes, of course. But only if they wanted to get in trouble with the EPA.

So, You can thank The Man for this phenomenon.

[nthretourNAFTW]

Originally Posted by KFN

A while back I did some work for a company that makes ECU diagnostic equipment for most of the big brands. It was explained to me that OBD II was mandated solely as a way of controlling emissions (since the architecture is already there, it's used for monitoring everything else too). By adapting engine settings to be most efficient relative to how the car is driven, performance is most definitely affected. I haven't noticed it yet with the M3, but my M Coupe was much quicker and more responsive on the way home from the track.

I asked if they could program my car for max power all the time and they said yes, of course. But only if they wanted to get in trouble with the EPA.

So, You can thank The Man for this phenomenon.

Yes it screws up a performance car by always returning to 'sad' mode by default unless spanked out of it regularly. I think it is the true cause behind the fabuled lack of torque critic. It's not the engine but this moronic software ! The engine -if ECU'ed properly lacks no torque at all down low. But in sad mode the ECU is unwilling to give easy access to that torque.

I have noticed improved mpg if you reset mpg counter just after a good rip and mediocre mpg in sad mode. So it doesn't even seem to be good for emissions. Is it trying to preserve the engine ? Knowing adaptive closed loop system is extremely hard to design, I think what we have is software with too many variables feeding multiple interdependent closed loops which was impossible to design 100% predictably and checked for millions of possible states. It's over designed with potent unwanted side effects.

Someone should really hack the whole ECU system and clean out that excessive big brother adaptation from the code.

[Beemdog]

As mentioned, most modern cars have adaptive tunes, but perhaps the extent of the adaptives is greater in some (like the E9x M3). My Viper has adaptive parameters that get cleared every time I blow in a new tune (with a handheld SCT programmer), and you can definitely hear the difference in the way it runs (decel backfires go away for a few miles, for instance). That car has such a great "hit" that even with a disconnected sparkplug, it goes like a raped ape (don't ask how I know this), so I can't really complain about the adaptive tuning much. However, on my M3 there have been times when I thought it should run stronger (cool, dry air) and it hasn't done so-- which left me wondering about it's apparent power moodiness.

Maybe one of the aftermarket tuners here could enlighten this situation a bit.

[Flying Ace]

Originally Posted by Edward

Precisely. If grantmax weren't preoccupied with listening to Sting and pondering what tree bark was made out of, he could be a bit more focused on properly training his car computer. But to no avail-his car wants to be a dog more than his actual new dog.

to make an assertion like this....me and Beemdog are going need pictures of said dog.

-woof

[Beemdog]

Can't blame grantmax for wanting to be a dog. And tree bark is awesome as long as you wet it down regularly.

[Edward]

Originally Posted by Beemdog

Can't blame grantmax for wanting to be a dog. And tree bark is awesome as long as you wet it down regularly.

Beemdog is barkin up the wrong tree. The kinda bark that grantmax dreams of are a bit oaky. No amount of wetting down can restrain it.

[grantmax]

Originally Posted by Beemdog

Can't blame grantmax for wanting to be a dog. And tree bark is awesome as long as you wet it down regularly.

His name is Tree Bark. What's left to ponder?

[grantmax]

Originally Posted by Flying Ace

to make an assertion like this....me and Beemdog are going need pictures of said dog.

-woof

See above. This post delivers.

[Edward]

That's not your floor. Where is that? grantmax

[Beemdog]

Originally Posted by grantmax

See above. This post delivers.

Maybe grantmax should change his forum name to "The Mailman".

Since he delivers.

He would then know why he's being abused by the forum dawgs.

Nice furry photo, BTW.

[grantmax]

Originally Posted by Edward

That's not your floor. Where is that? grantmax

Saks, bro. I had pictures flown in for you guys. My car is too busy underachieving.

[Edward]

grantmax

See you at Teuscher. Wait. Let's go get a drink, not coffee. It's 3:15 which is pre drinks drink time before dinner.

Beemdog if you're local come join. I'll be revving my Jaguar.

[Beemdog]

Originally Posted by Edward

grantmax

See you at Teuscher. Wait. Let's go get a drink, not coffee. It's 3:15 which is pre drinks drink time before dinner.

Beemdog if you're local come join. I'll be revving my Jaguar.

Sounds great but I'm NoCal. Probably an hour or so from Flying Ace .