00:00 |
- In the next step of our process we want to give some consideration to the modifications that have been made to this vehicle and consider how these are going to affect the tuning strategy or in other words, what changes we know we're going to need to make to our tuning.
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00:15 |
Now this is where the Cobb worked example is a little bit unique because instead of working from a base calibration or a stock ROM file and making wholesale changes to that ROM file, as we've seen in the last step we're already working from an off the shelf map that we've downloaded which should, for all intents and purposes, be a pretty good starting point to get up and running with our tuning.
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00:37 |
That being said, we still want to give some consideration to those changes.
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00:40 |
We know that the map should be close, that's not to say it's going to be perfect and in this case there are a couple of other alterations that have been made to the vehicle that we need to account for as well.
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00:51 |
So let's start with the modifications that we know the vehicle's got.
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00:55 |
We've got an aftermarket Cobb intake system.
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00:58 |
So we know that this is going to be freer flowing which is great for power.
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01:02 |
The effect on our tuning however is that we know it's going to affect our mass airflow sensor calibration.
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01:08 |
The mass airflow sensor calibration is the key to the ECU's operation.
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01:12 |
If the mass airflow sensor calibration is not accurate, it's going to make it very difficult for us to deliver fuel accurately and also get our ignition timing on point.
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01:22 |
So this is going to be the first step, making sure that our mass airflow sensor calibration is correct.
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01:28 |
The off the shelf map that we're starting from has a modified mass airflow sensor calibration that should be perfect for the Cobb intake system but of course we want to pay special attention and make sure that that is in fact the case and make modifications if we see that there are still errors present.
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01:44 |
In this case with the FA20 DIT engine, it is a direct injector only engine, there are no easy off the shelf upgrades for larger injectors so in this case we don't need to worry about our injector characterisation, we're not changing our injectors so we know that the factory injector characterisation is going to be sound, we don't need to worry about that aspect.
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02:06 |
The larger Cobb exhaust system fitted to the car should of course help flow through the exhaust system, allowing us to make more power and also increase boost beyond the factory level.
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02:18 |
Again the off the shelf calibration does take into account this larger exhaust system so, we should still be pretty close with the calibration that we're working from there.
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02:27 |
A couple of areas where we have got changes from the off the shelf map however, is the Cobb front mounted intercooler system and also the boost control solenoid.
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02:37 |
In particular the boost control solenoid is going to have quite a large affect on how close we are to our boost targets and we know from discussion with the Cobb engineers, that we're going to, in particular need to make some quite dramatic changes to our wastegate duty cycle tables and we'll deal with that as we get into the tuning.
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02:56 |
And again we are running here on the U.S. 90 octane fuel.
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03:00 |
This is a relatively good grade of fuel although with the high compression nature of the FA20 DIT engine plus adding boost pressure, we're still going to need to be vigilant of knock with this particular engine while we're tuning.
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03:14 |
While we are dealing with Cobb parts for this particular worked example, of course if you have modified your vehicle with non Cobb parts, the same considerations still need to be taken into account and of course with the FA20 DIT engine, because we won't be swapping injectors, our main consideration there is around the mass air flow sensor scaling.
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03:34 |
So regardless what parts you have got fitted to your particular vehicle, the same strategies that we're going to look at as we progress through this worked example will still apply.
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03:44 |
So now, let's move on with the next step of our process.
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