Avoiding de-tuning?
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The important difference in an UpRev tune is that it moves the tuning tables out of the hard coded ROM and into the volatile RAM. That allows easy editing and manipulation of the tables and the ability to switch maps on the fly without having to flash each time. As djamps explained, it is not a complete rewrite of the ECU code.
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I didn't mean it was like a new OS or anything. Uprev is just inserted code that allows the user to modify and read things that they otherwise could not. Things like use the cruise control to change maps, or read codes and do other things. The Uprev code is completely in the ECU OS not the OS its self. I may have reworded it wrong on the first first sorry.
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no, the o2 sensors wo'nt be the problem.
Here is what you are missing. When the tuner "tunes" the car he should set the target. The target is the a/f that the tuner makes the best for that car. Yes, but doesnt this vary with different octanes and weather conditions??
Long term fuel trims will do everything they can to meet that target. So as you drive the car will do nothing more than work it's hardest to hit that target a/f that the tuner set. Can this be the reason that sometimes my car seems to have better pull than others because the car may not be hitting the target a/f??
stock WOT is somewhere like 12.5. When you drive the ecu will adjust it so it's always hitting 12.5.
tuner changes that to 13.0. Now the car will only make adjustments to 13.0. Since the tuner changed it from 12.5 to 13.0 the car will not always adjust to hit ONLY 13.0. 12.5 no longer exists in the tune so the ecu would not know to change back to that. Again, the reason why sometimes my pulls are smoother and harder than others on my tuned map???
A properly tuned car with correct targets will only get better the more you drive it. Plain and simple.
Here is what you are missing. When the tuner "tunes" the car he should set the target. The target is the a/f that the tuner makes the best for that car. Yes, but doesnt this vary with different octanes and weather conditions??
Long term fuel trims will do everything they can to meet that target. So as you drive the car will do nothing more than work it's hardest to hit that target a/f that the tuner set. Can this be the reason that sometimes my car seems to have better pull than others because the car may not be hitting the target a/f??
stock WOT is somewhere like 12.5. When you drive the ecu will adjust it so it's always hitting 12.5.
tuner changes that to 13.0. Now the car will only make adjustments to 13.0. Since the tuner changed it from 12.5 to 13.0 the car will not always adjust to hit ONLY 13.0. 12.5 no longer exists in the tune so the ecu would not know to change back to that. Again, the reason why sometimes my pulls are smoother and harder than others on my tuned map???
A properly tuned car with correct targets will only get better the more you drive it. Plain and simple.
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The pulls can change for many reasons. If the intake temps are higher due to sitting in traffic then the IATs will be high on that first pull. The car would then pull some timing to compensate for the higher intake temps. If you were cruising on the highway with lots of fresh air your intake temps are more like the ambient temps so the car won't be puling timing out.
Also, if for some reason the car is detonating it will pull timing back. False knock or true knock can do this.
Either way, if the targets are properly adjusted it will always try to target your new established targets. The ecu will never go away from the targets in the computer aka "de-tune". Just can't happen. It sees a number and then tries to hit it. That's all it does. It can't just make up numbers or new targets.
also, the difference in feel between pulls is a lot of times just a psychological "feel". At most you will swing maybe 5hp or so and 5hp on a 250hp car can't be felt with the seat of the pants. If you are actually making a noticeable change in feel then it's probably a significant change in hp which will not happen on a good tune. Especially for an NA car that has far less variables to be affected verses an FI car.
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07-29-2002 06:14 AM