piggibacks & ECU auto-learning
#1
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piggibacks & ECU auto-learning
I'm have being speaking with different tuners, and all of the says that the ECU only makes adjustements when it runs in closed loop mode, and that is when the car runs on low load and below 3500rpm +/-.
They also said that there is no adjustement made (learn) at WOT, because the ECU at WOT doesn't use the lambda sensors...it's all of this true? if this is true why are not recomended the piggybacks?
Another point is, if at WOT the ECU doesn't use the autolearning feature, why when you make a reset you feel diference in power?
They also said that there is no adjustement made (learn) at WOT, because the ECU at WOT doesn't use the lambda sensors...it's all of this true? if this is true why are not recomended the piggybacks?
Another point is, if at WOT the ECU doesn't use the autolearning feature, why when you make a reset you feel diference in power?
#4
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I reflashed my ecu with Orisis so it would stop trying to adjust around my UTEC tune. Orisis locks the ecu to one of five maps that can be toggled manually. Car runs much more consistently now.
Without the flash the ecu randomly switched it's own internal maps and tried to 'auto learn' around my UTEC tune. Totally annoying.
Without the flash the ecu randomly switched it's own internal maps and tried to 'auto learn' around my UTEC tune. Totally annoying.
Last edited by gothchick; 05-05-2008 at 06:41 AM.
#5
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Originally Posted by gothchick
I reflashed my ecu with Orisis so it would stop trying to adjust around my UTEC tune. Orisis locks the ecu to one of five maps that can be toggled manually. Car runs much more consistently now.
Without the flash the ecu randomly switched it's own internal maps and tried to 'auto learn' around my UTEC tune. Totally annoying.
Without the flash the ecu randomly switched it's own internal maps and tried to 'auto learn' around my UTEC tune. Totally annoying.
#6
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Yeah~ When the Open Loop threshold is passed (usually 25%TPS and 2,000RPMs), UTEC does have full control of timing and fuel. But keep in mind UTEC is basing it's fuel offsets from it's ECU interpolation for MAF, hence the term "Piggyback". If the ECU is trying to adjust around the UTEC in MAF mode, then the UTEC offsets will be off.
I believe MAP tuning is independent of the ecu though. Hopefully someone can validate that statement...
I believe MAP tuning is independent of the ecu though. Hopefully someone can validate that statement...
Last edited by gothchick; 05-05-2008 at 07:08 AM.
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#9
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Originally Posted by gothchick
Yeah~ When the Open Loop threshold is passed (usually 25%TPS and 2,000RPMs), UTEC does have full control of timing and fuel. But keep in mind UTEC is basing it's fuel offsets from it's ECU interpolation for MAF, hence the term "Piggyback". If the ECU is trying to adjust around the UTEC in MAF mode, then the UTEC offsets will be off.
I believe MAP tuning is independent of the ecu though. Hopefully someone can validate that statement...
I believe MAP tuning is independent of the ecu though. Hopefully someone can validate that statement...
#10
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Originally Posted by Biochem7
For the FI guys this won't be problem b/c the fuel is adjusted based on the MAP sensor. But I guess NA guys with the UTEC need to worry about this.
#11
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I think that even using MAF as reference with the UTEC you don't have to worry about any correction, BlackTuner confirmed that, always that you select the Open Loop mode in the UTEC parameters section.
Anyway my question was if there is really any correction made by the stock ECU at WOT
Anyway my question was if there is really any correction made by the stock ECU at WOT
#12
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Originally Posted by raditz
I think that even using MAF as reference with the UTEC you don't have to worry about any correction, BlackTuner confirmed that, always that you select the Open Loop mode in the UTEC parameters section.
Anyway my question was if there is really any correction made by the stock ECU at WOT
Anyway my question was if there is really any correction made by the stock ECU at WOT
Just got off the phone with TXS. In MAF Mode, the ECU still controls injector pulse width, and that is what UTEC bases it's fuel offsets from. The ECU does actually try to 'correct' back to the factory AFR values in MAF mode (but UTEC is still able to retain full control over Timing). This 'correction' process does take the ECU a good amount of time/ miles to 'learn' around the UTEC tune though.
I was also able to confirm with TXS that in MAP mode, the UTEC does have full control of both fuel & timing in Open Loop. The ECU is completely out of the picture here.
So to this end, an ecu reflash or MAP tune will alleviate the problem. If you are NA and wish to tune to MAP, you'll need a MAP sensor. If you're MAF tuned, you'll need an ECU reflash to compliment it.
Yeah, expensive hobbie we have here. Lol.
Last edited by gothchick; 05-06-2008 at 07:47 AM.
#13
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Yea gothchick, this is an expensive hobbie!!!!
Look at this post of BlackTuner, and you will see that you can have full control of fuel with the UTEC https://my350z.com/forum/showpost.ph...4&postcount=10
Anyway, the question was, if it's real that the stock ECU makes compensations at WOT? If that's real, why are cars that run rich and others lean?
If the stock ECU doesn't makes corrections at WOT, then a piggyback won't be so bad, isn't it?
Look at this post of BlackTuner, and you will see that you can have full control of fuel with the UTEC https://my350z.com/forum/showpost.ph...4&postcount=10
Anyway, the question was, if it's real that the stock ECU makes compensations at WOT? If that's real, why are cars that run rich and others lean?
If the stock ECU doesn't makes corrections at WOT, then a piggyback won't be so bad, isn't it?
#14
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Hmmm, I'll have to let BlackTuner elaborate more on that thread then... There may be subtle differences between year-models of ECU.
For instance, UTEC can change the redline on '03~'04, but can't change it on '05~'06 rev-ups. Maybe that same kind of dynamic is at play here as to how much control the UTEC actually has in MAF. Another difference may be the version of UTEC firmware that is running.
I know for my '06 rev-up, I couldn't hold a stable MAF (fuel - AFR) tune for more than a month or so with UTEC v2.8d. It would gradually run crappier and crappier, until it finally ran like ****. Resetting the ECU would temporarily solve the problem, until it started learning around my UTEC tune again. Very frustrating.
So, per Jeremy @ PF's advice, I reflashed the ECU... Then tuned using the re-flashed ECU as a reference point. Bingo - seven months later and it's still running like the day I tuned it (minus slight variations due to ambient temps - Winter vs. Summer).
UTEC isn't so great at Global Temp Compensations, so I've created several seasonal maps that can be switched manually.
For instance, UTEC can change the redline on '03~'04, but can't change it on '05~'06 rev-ups. Maybe that same kind of dynamic is at play here as to how much control the UTEC actually has in MAF. Another difference may be the version of UTEC firmware that is running.
I know for my '06 rev-up, I couldn't hold a stable MAF (fuel - AFR) tune for more than a month or so with UTEC v2.8d. It would gradually run crappier and crappier, until it finally ran like ****. Resetting the ECU would temporarily solve the problem, until it started learning around my UTEC tune again. Very frustrating.
So, per Jeremy @ PF's advice, I reflashed the ECU... Then tuned using the re-flashed ECU as a reference point. Bingo - seven months later and it's still running like the day I tuned it (minus slight variations due to ambient temps - Winter vs. Summer).
UTEC isn't so great at Global Temp Compensations, so I've created several seasonal maps that can be switched manually.
Last edited by gothchick; 05-07-2008 at 12:48 PM.
#15
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Originally Posted by gothchick
For instance, UTEC can change the redline on '03~'04, but can't change it on '05~'06 rev-ups. Maybe that same kind of dynamic is at play here as to how much control the UTEC actually has in MAF. Another difference may be the version of UTEC firmware that is running.
Originally Posted by gothchick
I know for my '06 rev-up, I couldn't hold a stable MAF (fuel - AFR) tune for more than a month or so with UTEC v2.8d. It would gradually run crappier and crappier, until it finally ran like ****. Resetting the ECU would temporarily solve the problem, until it started learning around my UTEC tune again. Very frustrating.
If you take the page 32 from the UTEC manual, in the definition of Open Loop Fuelling, you can read...
...Whe Open Loop Fuelling is enabled, the UTEC uses its own background fuel table to determine injector on-time instead of the factory ECU's fuel table once the car is past the Open Loop Threshold parameter setting. This allows the UTEC to drive the injectors completely independent from the factory ECU.
Originally Posted by gothchick
So, per Jeremy @ PF's advice, I reflashed the ECU... Then tuned using the re-flashed ECU as a reference point. Bingo - seven months later and it's still running like the day I tuned it (minus slight variations due to ambient temps - Winter vs. Summer).
Originally Posted by gothchick
UTEC isn't so great at Global Temp Compensations, so I've created several seasonal maps that can be switched manually.
Last edited by raditz; 05-07-2008 at 11:27 PM.
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