Bob Cosby

I am familiar (in the basic sense) with adaptive strategies for the ECM. However, not when it applies to how a car runs at any given point in WOT conditions. Perhaps someone will provide documentation to prove me wrong, but in the meantime, I simply don't believe you'll run a better 1/4 mile time by beating on the car for 30 minutes prior to a run. Sorry, I'm just not buying it.

No facetiousness on this one, Jason.

Bob Cosby

Wait - I should add to that....there very well could be a mileage/time period for a new car in which the ECM restricts power level (until the motor is 'broken in'). I have no idea if that applies to Camaro, but this is something I could certainly see as possible (though unrelated to any adaptive strategy issues).

HuJass

I did a very quick serch on adaptive learning and it does exist. PCMs will not learn in open loop mode, only in closed loop.
When the battery cable is removed, everything it has learned will be lost. If you baby the car, then you may see an improvement by removing the cable.
If you hammer on it and then remove the cable, you will see a loss of power.
One guys claims that he lost 40 hp by removing the cable (verified on a dyno). He said it got better after about 20 minutes of hard driving.

It does exist. I would suggest doubters talk with their GM Goodwrench techs (especially the driveability techs) for more details.

Bob Cosby

Concur with adaptive learning, but color me a doubter - I don't believe I lose 40 HP by not beating on the car after removing the battery cable.

I don't have a GM Goodwrench tech (many of which I would trust just as much as I trust my GM salesman).

speeding2fast2c

Now I have never heard of this one before, and I personally find this idea less likely to believe then an adaptive ECM (which does exisit by the way).

The adaptive ECM isn't going to change the horsepower of the vehicle. The only thing that I know that it is doing is remembering shift points. Which in theory can make a vehicle quicker or slower. The remembering of shift points to my knowledge is used more for a fuel economy stand point as opposed to a performance stand point. (though again shift points can make a vehicle quicker or slower).

I'm not going to look this up, because honestly I know it exisits. If you doubt me, please take the time to look into it on your own.

Does anyone know if i was right or wrong about the switch for sport mode, comfort mode, etc???????

Bob Cosby

As I stated above, I concur with the adaptive strategy being present - including perhaps different shift rpm under varying conditions. What I do not concur with is that it applies to WOT shift points.

BTW, I didn't make the claim that such a thing existed. If I did, I would provide my sources, or I would say that was an opinion, and provide the evidence on which I based that position.

Z28Wilson

Agreed. At Wide Open Throttle, an ECM engineer should not be as concerned with fuel mileage and what the driver would want under lesser, more "normal" driving conditions. That's just dumb.

When the driver has his foot to the floor, I think it's pretty clear that said driver is expecting maximum performance at that moment, all other variables (within tolerances) be damned. This is why I also don't buy the argument that a car will "get faster" after several WOT runs - WOT is WOT, there should be no second-guessing what the driver wants at that point regardless of how it has been driven before.

I can't exactly see an ECM programmed to do the following:

(floor it) "Hmm. I don't think he/she really meant to do that based on how I've been driven lately, so I'm going to cut back fuel and lower shift points".

(floor it again) "Hmm, interesting, if he does it a couple more times I'll adjust."

......

(floor it for the 5th time in as many minutes) "Ahhh ok, what he wants is maximum power, well I guess I'll let him go ballz-out now!"

The only time I could maybe see any restrictions at WOT come into play is if the ECM is programmed this way for the first xxxx miles so as to allow proper break-in. If that's the case, it has nothing to do with how the driver drives it.

boomer78

Lots of cars have certain tricks or preventative measures:

GT500 IIRC has a (or did) restrictive mode for the first certain miles or 50 starts, whichever came first.

Other cars I've heard have a restrictive tune that is unlocked once at the dealership to stop car delivery guys/services to not beat on the cars or do damage to the car prior

Heck even some M cars have redlines that change as the vehicle warms up.

I know the post 05 mustang also has an adaptive ECM.
IIRC the computer learns and populates the tables based on idle with/without AC compressor and the first 'x' number of driving miles. (and shift points for auto's)
But it's for the closed loop tables. (The procedure is in the owners manual under replacing a battery) This is why guys have the ritual after the winter of reconnecting the battery, running the procedure and then runnig the snot outta the car) If you don't it just takes more time to adapt, and you might get slightly worse mileage.

Open loop (WOT) the computer ignores all feedback from the sensors

speeding2fast2c

Ok, all of the adaptive ECM stuff aside, can someone please answer this question I've asked twice:

Does anyone know if i was right or wrong about the switch for sport mode, comfort mode, etc???????

Bob Cosby

I have no clue. Sorry.

notgetleft

Could one of you that think the ECM relearns shift points please post some screenshots or at least list the parameters from our favorite tuning suite of the transmission shift tables and any modifiers related to this learning?

That's what i thought.

If it would help, i could show you examples of things the ECM does learn(when i get home anyway). Just off the top of my head i can:

adjust fuel learning
- enable/disable both long term and short term fuel corrections
- i can adjust the maximum range of short and long term fuel trims
- i can adjust how fast/often short trims adjust long trims
- i can adjust maximum step size the STFT can impact the LTFT
- i can even tailor the rate the ECM toggles STFTs based on O2 switching speed
adjust spark learning
- enable / disable the octane scalar
- adjust how quickly that scalar gets adjusted
- adjust both the high (max) and low (min) spark tables to confine the range of learning

Torque management supposedly has some learning on it, but since most people just disable it i doubt much adjustment is built into the commercially available tuning software.

Resetting your ECM at the track does 2 major things that affect performance
- reset the octane scalar to 1 (full high octane table), if you had been getting a lot of knock the ECM will degrade the octane scalar and use the low octane table more heavily.

- reset LTFTs. Most cars are programmed pig rich form teh factory, and WOT LTFTs are derived from non-PE high load cells that are often lean in stock tunes. This leaves you with positive fuel trims at WOT, dumping extra fuel on an already fat AFR.

RobDarden

I think part of the problem is the rear end. If the new car had a 3.73 it would be quite a bit quicker. Call me crazy!

MetalDragon

The only switching I'm aware of is to Comp mode, but this only affects stability / traction, not shift points and the like.

HuJass

I don't know if it learns shift points, but from my cursory look earlier today, it appears that the ECM will use different fuel trims and spark advance curves based on how the car was/is driven.
All this is done in closed loop mode only.

I'm not going to look into this any further. I know it exists. The internet probably has plenty of info on this feature for all those who want to learn about it.

rpepka

The car is going to the dealer this morning.