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Hey guys,
Sorry for the late reply, it's been a busy week and I keep forgetting to come back and see what's going on.
The adaptations that the ECU makes are mainly to do with smoothness rather than power. Right from the factory, all cylinders in your engine will not fire evenly, there will be small variations in compression ratio, fuel flow, friction, which means that some cylinders will fire harder than others. As the car ages and starts to wear, these differences become bigger. The ECU is able to sense which cylinders are firing hard, and which ones are falling behind, and then compensate by adjusting the fuel to each cylinder so that they all fire evenly, making the engine run smoothly. It does other adaptations too such as compensating for fuel trims etc, but you get the gist.
Whenever you write a new tune to the ECU, the ECU resets the adaptations and needs to relearn. This usually takes around 500kms as a rough guide. But all you may notice over that time is the engine getting smoother, there should be little or no change to power or performance in general.
The tune is a basically a digital file, and it is protected against corruption by the ECU with a very complex checksum algorithm. Basically, if a single bit (ie a 1 or a 0) changes in the tune, the checksum won't add up, and the ECU will prevent the car from starting. Period.
Basically, what I'm getting at is that if the performance is variable from run to run, then that is likely to be for a reason other than the tune. The tune itself can't change, although it may be exacerbating something else. The most obvious reason for variable performance in a turbo-charged car is heat soak, and I'm sure that everyone here has experienced that in the past. Another reason might be a problem with a component of the engine (the diverter valve is a good example) causing variable performance.
I notice most of you guys are in QLD or NSW which is a bugger because I'm here in Melbourne. If anyone here in Melbourne is having similar issues, please let me know. I'm happy to put the car on the dyno at my expense and see what is going on.
One other thing comes to mind about the comment that the car runs harder on part throttle than on WOT. When at part throttle, the ECU monitors the O2 sensors in the exhaust, and uses that information to ensure that the fuel is burning at a perfect 14.7:1 stoichiometric mixture, and constantly makes adjustments to the mixture to keep it there. This is called closed-loop mode. When you go to WOT, the ECU goes into open-loop mode and stops looking at the O2 sensor, and deliberately runs the engine rich. It figures out how much fuel to inject by looking up pre-calibrated look-up tables. Running rich at WOT helps keep the charge cool, and helps prevent detonation. That's why you will often see turbo cars with an air-fuel ratio of less than 12:1 at WOT.
If you make mods to the car to enable to it to breath better (ie CAI, exhaust or parts thereof etc), without adjusting those fuel maps accordingly, the car will start running lean at WOT. The mods will allow more air through, and yet it will still be delivering the same amount of fuel at WOT as it did when it was stock. When the engine runs lean at WOT, it is more likely to experience detonation, and so the ECU will retard the ignition timing in response, reducing power. That's why the Superchips Stage 2 (and 3 and 4) tunes come with a list of hardware pre-requisites.
I'm not saying that is what is causing the issues mentioned above, but I am saying that if you make mods to make the engine breathe better without remapping the ECU accordingly, don't be surprised if you make less power than stock.
Anyway, that was a long post, so to recap:
1) ECU adaptations mostly affect smoothness and not performance.
2) The tune can't change, but variability in performance can be caused by many reasons
3) I'm happy to stand behind the product though, and so am happy to assist anyone here that is having issues that may be tune-related.
4) Please don't take any of the above as diagnosis, without having seen any of your cars I have no idea what is going on. I'm just trying to offer suggestions as to what might be going on.
5) Any Melbourne folk having an issue, please call me on 0411 592 157. I'm happy to put a car on the dyno on my coin and post the results here, good or bad, and we'll see if we can find what is going on.
6) If anyone else here is having issues, whether you bought the tune from me or not, please feel free to call me and I will do what I can to help.
Cheers
John
Sorry for the late reply, it's been a busy week and I keep forgetting to come back and see what's going on.
The adaptations that the ECU makes are mainly to do with smoothness rather than power. Right from the factory, all cylinders in your engine will not fire evenly, there will be small variations in compression ratio, fuel flow, friction, which means that some cylinders will fire harder than others. As the car ages and starts to wear, these differences become bigger. The ECU is able to sense which cylinders are firing hard, and which ones are falling behind, and then compensate by adjusting the fuel to each cylinder so that they all fire evenly, making the engine run smoothly. It does other adaptations too such as compensating for fuel trims etc, but you get the gist.
Whenever you write a new tune to the ECU, the ECU resets the adaptations and needs to relearn. This usually takes around 500kms as a rough guide. But all you may notice over that time is the engine getting smoother, there should be little or no change to power or performance in general.
The tune is a basically a digital file, and it is protected against corruption by the ECU with a very complex checksum algorithm. Basically, if a single bit (ie a 1 or a 0) changes in the tune, the checksum won't add up, and the ECU will prevent the car from starting. Period.
Basically, what I'm getting at is that if the performance is variable from run to run, then that is likely to be for a reason other than the tune. The tune itself can't change, although it may be exacerbating something else. The most obvious reason for variable performance in a turbo-charged car is heat soak, and I'm sure that everyone here has experienced that in the past. Another reason might be a problem with a component of the engine (the diverter valve is a good example) causing variable performance.
I notice most of you guys are in QLD or NSW which is a bugger because I'm here in Melbourne. If anyone here in Melbourne is having similar issues, please let me know. I'm happy to put the car on the dyno at my expense and see what is going on.
One other thing comes to mind about the comment that the car runs harder on part throttle than on WOT. When at part throttle, the ECU monitors the O2 sensors in the exhaust, and uses that information to ensure that the fuel is burning at a perfect 14.7:1 stoichiometric mixture, and constantly makes adjustments to the mixture to keep it there. This is called closed-loop mode. When you go to WOT, the ECU goes into open-loop mode and stops looking at the O2 sensor, and deliberately runs the engine rich. It figures out how much fuel to inject by looking up pre-calibrated look-up tables. Running rich at WOT helps keep the charge cool, and helps prevent detonation. That's why you will often see turbo cars with an air-fuel ratio of less than 12:1 at WOT.
If you make mods to the car to enable to it to breath better (ie CAI, exhaust or parts thereof etc), without adjusting those fuel maps accordingly, the car will start running lean at WOT. The mods will allow more air through, and yet it will still be delivering the same amount of fuel at WOT as it did when it was stock. When the engine runs lean at WOT, it is more likely to experience detonation, and so the ECU will retard the ignition timing in response, reducing power. That's why the Superchips Stage 2 (and 3 and 4) tunes come with a list of hardware pre-requisites.
I'm not saying that is what is causing the issues mentioned above, but I am saying that if you make mods to make the engine breathe better without remapping the ECU accordingly, don't be surprised if you make less power than stock.
Anyway, that was a long post, so to recap:
1) ECU adaptations mostly affect smoothness and not performance.
2) The tune can't change, but variability in performance can be caused by many reasons
3) I'm happy to stand behind the product though, and so am happy to assist anyone here that is having issues that may be tune-related.
4) Please don't take any of the above as diagnosis, without having seen any of your cars I have no idea what is going on. I'm just trying to offer suggestions as to what might be going on.
5) Any Melbourne folk having an issue, please call me on 0411 592 157. I'm happy to put a car on the dyno on my coin and post the results here, good or bad, and we'll see if we can find what is going on.
6) If anyone else here is having issues, whether you bought the tune from me or not, please feel free to call me and I will do what I can to help.
Cheers
John
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