07 Charger SRT8 lazy off the line

[Mike_Levy]

You can reset the tranny adaptives from the Predator, not the engine ones. This is where alot of people misunderstand. They think resetting the adaptives from the Predator is the same as pulling fuse 11. Its not. It 2 different systems. One is for the ECM, the other for the TCM.


The car will always adapt. Thats what its designed to do. It just takes time.

[tomssrt8]

Thanks, that clears things up.
So in order to comapre 2 tunes back-to-back, it's better to reset the tcm AND the adaptives after each tune upload ?

[Quick]

Thanks, that clears things up.
So in order to comapre 2 tunes back-to-back, it's better to reset the tcm AND the adaptives after each tune upload ?

I've always wondered about that... The adaptives "adapt", and I'm under the impression that they do so in a fairly short period of time/driving. So why reset the adaptives? They're going to end up at the same place whether you reset them or not, right?

[RFischer]

Adaptive learning - you can reset it, but it will learn your granny driving ways - again ...

[fordomatic69]

tomssrt8, if you want to compare apples to apples, then I would reset the adaptives with every tune loaded. If you load a tune, drive the car around for a while then load another tune, the adaptives for your previous driving habits remain in the memory. At least resetting them brings you back to the same baseline. Just remember that the car will become "Lazy off the line" at some point down the raod unless you pound on the car 100% of the time (which I doubt).

[Quick]

tomssrt8, if you want to compare apples to apples, then I would reset the adaptives with every tune loaded. If you load a tune, drive the car around for a while then load another tune, the adaptives for your previous driving habits remain in the memory. At least resetting them brings you back to the same baseline.

But if you didn't reset the adaptives aren't they just going to adjust for the new tune and you're going to end up at the same place anyway? No one has been able to tell me just how long it takes the adaptives to adapt. What reason do you have to believe it's more than about 10 minutes?

Just remember that the car will become "Lazy off the line" at some point down the raod unless you pound on the car 100% of the time (which I doubt).

Uhhh, any evidence of this? Other than "seat of the pants"? (SOTP can be significantly effected by "everybody says...").

Can you list these "adaptives" everybody talks about? I know about the short term and long term fuel adaptives and have a cursory idea of how they work. Your long term fuel adaptives do factor into fuel determination for WOT open loop operation. What else?

And again, how long does it take for a change to be reflected in these adaptives?

Are any of these "adaptives" adjusted during open loop mode operation? The long term fuel adaptives are not. So what is it that you are changing/adjusting by pounding on your car?

[jtfinklea]

Quick I found this online and the author states he got this info from a DCX Engineer.

PCM Fast Learn Mode By Daless
The Jeep’s PCM performs several functions controlling Air Fuel ratios via Injector Bandwidth and Ignition Timing.
These “outputsâ€

[Quick]

Thanks for finding that... but I'm skeptical that it's correct. Take for example the long term fuel adaptives. I do not believe these are ever "set" and do not change after that. I believe they are constantly adapting. Adjusting for changes as your air filter gets clogged over time, changes in altitude, etc. If for no other reason, I don't believe it would get approved for emissions if it "set" at some point and did not change after that. I suspect the guy must have misinterpreted or misunderstood what the engineer said or the information was just wrong. I can't believe that part would be different for a TJ either.

Here's a couple of things I heard it from a SRT Engineer (they have a monthly "SRT Engineer Chat" that rotates among Ekool's sites). The PCM hardware and, at least some of the firmware, is made to be common across different engines. I forget, but I think the PCM is the same for the 5.7L and 6.1L engines? At engine startup, if the PCM is new or has been reset (and maybe every time) it will start the engine with a default, generic, set of parameters and code. Within about 0.6 seconds the PCM will determine the engine type and switch to more specific parameters and code. (ok, not useful information but just a neat bit).

The only adaptive memory listed in the service manual is the short term fuel adaptive memory and the long term fuel adaptive memory. I would tend to think there are more. Apparently there are modules other than the PCM that have adaptive memory? The Predator has the option to reset the TCM adaptives. That might imply at least one other adaptive memory. I don't know that the TCM adaptive memory resides on the PCM or if it's only the control to reset that memory that resides on the PCM (currently the Predator only accesses the PCM).

Someone like Johan would know all this stuff but I think DiabloSport considers it company confidential information so someone would have to get him pretty drunk to spill the beans

[fordomatic69]

I agree that the adaptives are probably always "adapting" that is why I would think in order to get an apples to apples comparison of whether a tune improves performance or not, you need to start with a "clean slate" so to speak.

1. Reset the adaptives (either through the Predator or pulling fuse 11 or whatever else floats your boat) and load your factory defaults.
2. Try a run with whatever your measurement tool of choice is (Dashhawk, Predator, D-PIC Gauge, EVIC).
3. Go back to your original starting point, Reset the adaptives again the exact same way you did it last time. Load your new tune and try another run (you should log for LT and ST Knock to make sure the ECM is not pulling timing due to detonation).

Keep in mind though if you are running at WOT, the adaptives are probably not used anyway (open loop) but none of us know that 100%. Only the engineers at DCX know for sure and I doubt they will be forthcoming with ALL the information (gotta keep some things secret for job security, I do ).

[Quick]

That would be one way to compare. I would think a better comparison would be after the adatives (if any are applicable) have adapted. This is what you're going to be running for the long term. Again, there is that burning question of how long do the adaptives take to settle down? Let's say it's a couple hundred miles (personally I'd expect it to be on the order of 10 minutes or less). You would probably want to make your measurements to compare after that. You're thinking that reducing the variables makes for a better comparison. I'm saying the number of variables don't matter since you're not trying to identify exactly what made the difference but the end result. For example if you're comparing 2 CAI's. You could see different results after the adaptives do whatever they're going to do in response to the CAI.

The main reason that people always reset the PCM when doing dyno comparisons on something like CAI's is because they're doing them back to back. And as far as I can see no one seems to know exactly what adaptives there are and how long they take to adapt. If it's something like 10 minutes then they should allow them to settle and then take measurements. If it takes longer or some other driving conditions or time then it gets impractical to do that and maybe reseting is the best you can do. Probably gives you some comparison but I'm not sure how much confidence I'd have in the results.

The main thing that I'm skeptical about is this common perception that your car gets "sluggish" after puttering around for some amount of time. Why?