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- The term component protection is common when it comes to tuning factory ECUs.
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00:05 |
The name is fairly self explanatory and simply provides the tuner with a series of tables that are used for different operating conditions.
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The idea is that the ECU will switch between these tables as required, in order to ensure engine reliability.
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00:20 |
The key to this component protection really centres around controlling combustion temperature and hence the temperature components like the pistons and valves are subjected to.
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00:30 |
While we're focusing on the ECU control logic here, rather than the specifics of tuning, optimising the lambda targets can offer significant gains in power.
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00:40 |
In some instances, these targets will always be lambda 1.0 regardless of RPM or load and hence adding fuel can be beneficial.
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00:49 |
In other instances, you may find that the component protection lambda targets are ridiculously rich which can kill engine power.
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00:56 |
Understandably in this case, leaning out these targets can pay dividends.
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01:00 |
Sensors could be used to monitor parameters such as exhaust gas temperature directly, however manufacturers go to great lengths in order to reduce their costs and hence a complex model is used where the ECU constantly calculates the likely exhaust gas temperature, based on operating conditions.
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01:19 |
Once the ECU has exhaust gas temperature data, it can use this as a switching point for normal or component protection tables.
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01:27 |
One we know that the exhaust gas temperature is getting too hot, we need a way to combat this and of course an effective method of cooling things down is to run a richer lambda target.
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01:37 |
Let's take a look at these maps from our mark 5 Volkswagen Golf GTI to see how these tables work.
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01:43 |
The first table we'll look at is referred to as lambda driver's wish which is a relatively small table with a size of 6 x 15.
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01:52 |
This defines the lambda targets the engine will run normally or in other words, when it's not operating in component protection.
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01:59 |
The axes for this table are engine speed vs relative torque and the German acronym for this table is LAMFA.
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02:07 |
The lambda for component protection tables are interestingly much higher resolution with a size of 16 x 12 instead of 6 x 15.
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02:16 |
This gives finer control over lambda targets.
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02:19 |
The other difference with the component protection lambda tables is that instead of requested torque, the load axis is relative cylinder fill.
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02:27 |
It's a subtle but important difference.
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02:30 |
For interest, the acronym for this table is KFLBTS and there are multiple tables here, including separate tables for charge flaps open and charge flaps closed.
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02:40 |
It's not difficult to see the effect of these component protection maps in action when the tables are requesting lambda targets as rich as 0.71 and as rich as 0.66 in the charge flap open table.
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02:54 |
Sufficed to say, with factory lambda targets this rich, they're not doing anything for power.
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02:59 |
While we're discussing these tables, it's worth noting that there are two separate ways of dealing with them.
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03:05 |
Some tuners tune the tables separately to their desired lambda targets, retaining the switching based on EGT as intended.
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03:12 |
Others prefer to force the ECU to run permanently in component protection mode, thereby giving access to the higher resolution tables all of the time and then simply adjusting the targets to suit their desired requirements.
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03:25 |
From my perspective, this is simply personal preference and either method can work.
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03:31 |
It's more important to just understand the system and the implications of which table the ECU will work in.
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03:37 |
Otherwise you can become very frustrated, wondering why the ECU appears to be tracking lambda targets vastly different to what you think you're asking for.
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03:45 |
Let's just recap this module before finishing up.
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03:49 |
In modern ECUs you'll usually find component protection tables which are designed to achieve exactly what their name suggests.
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03:56 |
Often the ECU will switch to the component protection tables as a result of modelled exhaust gas temperature and this can result in very rich lambda targets which can hurt power.
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04:06 |
Often the component protection lambda tables also offer better resolution than the normal tables and it's possible to take advantage of this resolution by forcing the ECU to always reference these tables instead, if desired.
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