00:00 |
- The G4+ offers some advanced options which provide very accurate boost control in turbocharged engines.
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00:07 |
We're going to look at the different control strategies and what you need to do to set them up.
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00:13 |
First, we need to set an auxiliary output to control the wastegate solenoid.
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00:17 |
This is the solenoid the ECU will use to control boost.
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00:21 |
We do this by selecting an unused auxiliary output and setting it as boost solenoid.
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00:26 |
You can see we now have the option of setting the solenoid frequency and this is quite important.
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00:33 |
We need to choose a frequency that the solenoid will work comfortably at and this is dependent on the solenoid.
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00:40 |
Most popular solenoids tend to work best in the 15-30 hertz range so we're going to choose 20 hertz.
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00:48 |
Now we need to set up the boost control parameters.
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00:51 |
We can do this by accessing the ECU settings menu and choosing boost setup from the boost control menu.
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00:58 |
Here we need to decide if we want to use open loop or closed loop boost control.
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01:03 |
Open loop is simpler and easier to set up but if the boost level isn't exactly what you want, the ECU won't do anything to try and correct this.
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01:12 |
In this module, we're going to look at how to configure an open loop system.
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01:17 |
There are still a few more parameters to adjust before we get to adjust the boost.
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01:22 |
RPM activation and MAP activation are lock out points below which the boost control system won't operate.
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01:28 |
These make sure the boost solenoid won't be working when you don't want it.
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01:33 |
Deactivation timeout is only relevant to closed loop control and will have no effect in open loop mode.
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01:41 |
If we go back into the ECU settings menu and click on boost control, the next option we have is multiple boost tables.
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01:48 |
This lets us configure up to three separate boost tables which can be controlled by the driver.
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01:54 |
For simplicity we'll just set up a single boost table.
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01:59 |
Next in the boost control menu we have wastegate and this is where we find the tables to actually control boost pressure.
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02:06 |
First of all we have compensation tables for engine temperature, intake temperature and gear.
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02:12 |
These tables let you adjust the boost dependant on these parameters to ensure safety.
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02:17 |
To start with, it's a good idea to make sure these compensation tables are all zeroed so they won't influence your boost tuning.
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02:25 |
If you want to use these compensations, set them up once the main boost control is configured.
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02:31 |
Lastly we have the wastegate duty cycle one table which is where we can directly enter wastegate duty cycles.
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02:38 |
By default, this is a 3D table with RPM on the X axis and throttle position on the Y axis.
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02:44 |
As usual, these axes are adjustable and you can use any inputs you want.
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02:50 |
Altering numbers in the wastegate duty cycle map will adjust the boost level.
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02:54 |
Start by zeroing all the numbers in the table and ensuring your base boost level is where you need it to be.
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03:01 |
If the boost is already exceeding your target then the boost control tables won't be able to help you.
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03:08 |
In this case you'll need to make mechanical changes to the wastegate or turbo system.
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03:14 |
When tuning the wastegate duty cycle map, make small changes to the numbers and start with less boost than you want while slowly increasing towards your target boost level.
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03:25 |
Excessive boost pressure can quickly damage an engine so it's recommended to take your time setting up boost control and always make sure you have a MAP limit configured to prevent accidental overboost.
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