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Old 02-27-2006, 01:56 PM   #1
the_poser
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Default Learning ECU?

I know the ECU in the cars are a "learning ECU" and will make adjustments according to how you drive, etc...
I've heard it said that after you get a reflash [EcuTek, Cobb, etc...] you should drive really hard so it learns the way you want to drive and gives you the most performance.
is this true?
if so then, the wagon I bought already had the ECu reflashed w/EcuTek, can I disconect the battery for a few minutes and let it reset and then drive the dog out of it and have the same effect?
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Old 02-27-2006, 02:40 PM   #2
Jon [in CT]
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The ECU doesn't learn your driving style. It learns fuel trims and your fuel's knock resistance. It's best to avoid resetting your ECU as much as you can.
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Old 02-27-2006, 06:50 PM   #3
parid
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For more information, see the stickied thread in this forum titled:

Re-Mapped ECU Learning Trick 10-20hp in 5 seconds
http://forums.nasioc.com/forums/showthread.php?t=302047
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Old 02-27-2006, 07:14 PM   #4
the_poser
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thanx for the link
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Old 02-27-2006, 08:21 PM   #5
nhluhr
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Um, don't waste your time resetting the ECU and doing the ECU-Learning trick. That is just a way to accelerate the learning process that your car has already gone through. If you reset your ecu now, you'll just be driving a car that doesn't know its knock limits (no knock correction tables populated), doesn't know its fuel learning (no long term fuel trims populated), and wants to run the most aggressive timing (which is what this trick accomplishes).

In short, this trick makes your car either less safe or slower than it currently is. Neither is a desirable thing.
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Old 03-11-2006, 12:24 PM   #6
canosardines
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Quote:
Originally Posted by Jon [in CT]
The ECU doesn't learn your driving style. It learns fuel trims and your fuel's knock resistance. It's best to avoid resetting your ECU as much as you can.
How does it learn that?
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Old 03-31-2006, 02:01 AM   #7
cjfike
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Default Learning ECU?

Quote:
Originally Posted by canosardines
How does it learn that?
Learn what?

Oh! It learns via the Air Bag interface. After it deploys the air bag interface, you're gently knocked into a altered state. It reads your mind, finds out what you know, how you drive, and how many days you wear matching socks in a week. Then it tunes the engine accordingly.
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Old 04-07-2006, 11:08 AM   #8
jigga
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Quote:
Originally Posted by canosardines
How does it learn that?
by advancing timing through a corse trim until it feels that it is getting to the ballpark, then fine tunes the timing using another timing map known as the fine timing trim, and then keeping an eye on everything as you run the car. If you get a bad tank of gas, it sees that the car is more det-prone all of a sudden, and makes changes to its fine timimg trim map to cure the problem. If the problem is more severe, it starts to reduce the corse timing tim as well to take car of the problem. If all hell really breaks lose, there is a high-det map that it will fall back to..
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Old 04-17-2006, 02:52 PM   #9
Freon
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To add to the above, fuel is adjusted via a long term and short term trim. While cruising or driving under light load, the ECU tries to target a steady 14.7:1 AFR. It uses the feedback from your front O2 sensor to do this. If it is too rich, the fuel trim values lower. If it is too lean, they go up. Obviously short term changes faster than long term.

It then uses those values to guesstimate how much to hold the injectors open when you step on it hard (open loop). The O2 sensor gets "turned off" but it uses the current fuel trims and MAF sensor to know how much fuel to inject. There is a "target fuel map" it uses to know what fuel ratio it should try to get. As above, cruising it is 14.7:1, but at high RPM and high airflow, it will target more like 10:1 to 11:1. Again, it doesn't really know for sure if it is hitting the exact value since the O2 sensor is "turned off" at high loads, but it uses some basic math based on the measured air, RPM, fuel trim values, etc. to hold the injectors open the correct length of time.

The factory ECU is *very* smart. It probably has more learning ability than any aftermarket unit. Not bad for a $400 part...
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Old 04-24-2006, 03:46 PM   #10
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Quote:
Originally Posted by the_poser
I know the ECU in the cars are a "learning ECU" and will make adjustments according to how you drive, etc...
I've heard it said that after you get a reflash [EcuTek, Cobb, etc...] you should drive really hard so it learns the way you want to drive and gives you the most performance.
is this true?
if so then, the wagon I bought already had the ECu reflashed w/EcuTek, can I disconect the battery for a few minutes and let it reset and then drive the dog out of it and have the same effect?
This is highly dependant on the capability of the tuner and what he actually does with the parameters within the ECU. Tuning for power is one thing, maybe about 25% of a tune where as tuning for drivability and reliability, are about 50% of the tune. The other 25% well, that is up for debate, we have our own views, and we will leave it at that.

Many parameters have to be taken into consideration while tuning a vehicle, and how the client/customer will operate the vehicle. This will have a large impact on how the ECU adapts to your driving style OR in turn how the ECU adjusts the varying parameters in order to give you the proper power output for the task at hand.

Resetting the ECU will not really do much if the the car was properly tuned, where as a poor tune will cause the car to react quite a bit differently after a reset.

Cheers,
William T. Knose Jr.
Lead Programmer
I-Speed USA
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