00:00 |
- One of the hardest aspects to get used to for those more familiar with tuning aftermarket ECUs is that in most situations the tuning changes we want to make can't be performed live.
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00:13 |
What I mean by this is we can't run the car on the road or on the dyno and make adjustments to the fuel or ignition and see the results of those changes instantly as we could expect with any aftermarket ECU.
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00:28 |
Instead the tuning process requires us to make a test run on the dyno or the road make any required changes to the mapping, shut the engine off, flash the new map into the ECU and finally test again to confirm the effect of our changes.
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00:47 |
This is necessary because the maps in the ECU are store in read only memory and this information can't be altered while the engine's running.
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00:57 |
On the face of it this sounds like quite an inconvenience and potentially a very slow and time consuming way of tuning.
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01:06 |
In reality though when we're re-flashing a factory ECU, we can often confine the area of engine operation that we need to make adjustments to to the wide open throttle area only.
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01:19 |
Unless we've made dramatic changes to the engine configuration, such as adding a larger cam, often the idle and cruise areas of the engine operation will need little to no adjustment.
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01:32 |
It's important to understand that unlike tuning an aftermarket ECU, we will be starting with a calibration or tune that's very well matched to the stock engine.
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01:43 |
This means we aren't starting from scratch with no fuel or ignition maps at all.
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01:50 |
While the required tuning process will understandably depend on the level of modifications performed to the engine, a lightly modified engine, with an aftermarket exhaust, intake and perhaps a little more boost in a turbo charged car, will typically only need the full power area of the map adjusted.
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02:11 |
In this case the tuning process isn't that much different to a standalone ECU.
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02:17 |
We make a pull on the dyno, look at the results, make adjustments to the tune and then confirm the results.
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02:25 |
With an aftermarket ECU we can enter these changes into the map while the engine's running.
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02:30 |
But in the case of re-flashing, we need to perform one further step, which is to shut the engine down and flash our changes into the ECU.
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02:40 |
Of course there are situations where we will need to make more dramatic changes to the engine tuning, but in my experience by far the majority of re-flashing will focus mainly on the wide open throttle operation area only.
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02:55 |
As you'll learn with re-flashing, there are general rules that are applicable to most situations.
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03:02 |
But also often there are exceptions to these rules.
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03:05 |
While it's not possible to make live tuning changes to a stock ECU ROM file, a number of re-flashing software providers have developed options for some ECUs that allow a few critical maps to be temporarily stored and read from RAM where live tuning changes are possible.
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03:26 |
This isn't an option that's available with every re-flash package though, and is very dependent on the design of the stock ECU.
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