Practical Reflash Tuning: Step 3: Configure Base Tune File
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Step 3: Configure Base Tune File
43.44
| 00:00 | - Once we've got our calibration downloaded out of our ECU and saved, we can now go through and make some modifications to the base file to suit whatever changes have been made to the vehicle. |
| 00:11 | Now of course, here we are dealing with the Roush base calibration that is suited to the supercharger kit fitted as well as the fuel injectors so ultimately here, most of the heavy lifting has been done for us and there should on face value be very little that needs to be done here. |
| 00:27 | Regardless of this, we are still going to make some changes, and I'm going to go through here and discuss the changes that have been made so that if you're dealing with a stock vehicle that has a factory naturally aspirated calibration and you were converting to forced induction, you're still going to understand what changes have been made along the way here. |
| 00:48 | So let's get started and I want to begin by talking about the fuel injectors and the fuel control used in this particular vehicle. |
| 00:57 | In the late model Ford vehicles the engines are fitted with wideband air fuel ratio sensors. |
| 01:05 | And for this reason the ECU also continuously works in closed loop mode. |
| 01:11 | So let's have a look in our software, and at the moment we can see that we're on our fuel tab and we're also looking at our oxygen sensor tab underneath the fuel main tab. |
| 01:23 | Now there is a lot of data or parameters here but basically the ones that I'm going to be looking at are our closed loop enable temperature. |
| 01:31 | So we can see at the moment this is set to a factory value of 260 degrees centigrade and we also have our long term fuel trims master enable or disable. |
| 01:41 | So by disabling this, obviously this disables our long term fuel trims. |
| 01:44 | By setting our closed loop enable value to something like the maximum 2259 degrees centigrade, essentially that's going to eliminate the ECU ever going into closed loop mode. |
| 01:57 | Now the reason that I am mentioning this is because once we actually get into the tuning step, we're going to want to calibrate or rescale our mass air flow sensor to ensure that's accurate. |
| 02:09 | And there are two ways we can do this, it really comes down to personal preference. |
| 02:14 | We can disable the closed loop mode, in which case we'll use a MAF channel in our scanner to calculate the error between our commanded lambda and our measured lambda and we'll use that to populate a histogram. |
| 02:26 | Or alternatively what we can do is leave the closed loop mode enabled which is what we're going to do now, and then we would be using the combination of the short term and long term fuel trims to populate that same histogram. |
| 02:39 | So just showing you here where you can disable closed loop if your preference is to do so. |
| 02:46 | Let's move on and the next aspect we're going to look at, we're going to move across to our torque model and we're going to be looking here at our monitoring tab. |
| 02:56 | And we've got a parameter here called our IPC wheel torque error max. |
| 03:01 | Now IPC stands for independent plausibility check. |
| 03:05 | And essentially this is an inbuilt check that the Ford ECU does and it looks at our torque tables and if the calculated torque from the air flow doesn't match the torque tables, then this indicates that there is an error there. |
| 03:22 | And this can be problematic in some cases. |
| 03:25 | Even if we only have small errors, the IPC wheel torque error is a cumulative error so over time while we are driving the car, the IPC wheel torque error will increment. |
| 03:36 | So if it exceeds this maximum value here, it can end up causing the engine to go into a limp mode which obviously we want to avoid. |
| 03:44 | So the key point here is to make sure that this parameter is set to a value that's going to prevent a error occurring if we've got all of our tables correctly calibrated. |
| 03:56 | So somewhere in the region of 200000 to 500000 should be a good value to put in here provided of course the rest of our calibration is correct. |
| 04:06 | Now we're going to move back across and we're going to head to our air flow tab. |
| 04:12 | And on our air flow tab we want to click on the electronic throttle tab. |
| 04:16 | Now what we've got here is a number of parameters, again we don't need to be adjusting all of them but one that you may want to adjust here is our pedal position wide open throttle start. |
| 04:27 | You can see at the moment that's set to 500. |
| 04:30 | And it can be beneficial to lower this down, a lot of this comes down to personal preference. |
| 04:35 | But essentially the way that this works is that up 'til the point we reach our pedal position wide open throttle start value, the ECU will be using the driver demand torque table. |
| 04:47 | Once we get to our start position, then the throttle position will linearly move up until the wide open throttle position where we reach our pedal position wide open throttle end. |
| 04:59 | So essentially dropping this value down a little bit is going to produce more part throttle torque. |
| 05:06 | So what we're going to do here is drop this value down to 300. |
| 05:10 | Of course this does come down to personal preference so it's a good idea to understand how this factor or parameter works and also test to find out what your own personal preference is. |
| 05:21 | While we are on this tab it's also just worth mentioning here, we've got our throttle body model. |
| 05:27 | And this includes our predicted throttle angle table and it also includes our effective area table. |
| 05:35 | Now it's really important, I've already mentioned here, that these tables do need to be calibrated correctly and these numbers aren't numbers that you're likely to be able to fudge and get good results. |
| 05:47 | This really only becomes important if you are considering a throttle body change. |
| 05:51 | But if you are doing so, you need to have the correct values to put into these tables otherwise you're definitely going to have some problems with the engine's drivability and the ability to get good control over the throttle body. |
| 06:03 | Next we're going to head across to our torque management tab. |
| 06:07 | And we're going to be looking at a couple of parameters here, specifically under our ETC torque management, we're looking at our scheduled torque max and our torque max versus RPM. |
| 06:19 | If we click on our scheduled torque maximum table we can see this is a two dimensional table of our maximum torque relative to engine RPM. |
| 06:26 | So we wanna make sure that this is raised if we're modifying our engine, to suitable values. |
| 06:32 | We don't need to be too specific with this right now but we do need to raise it to make sure that it is at least above the expected torque that we're likely to see out of our engine. |
| 06:43 | If we click on our torque max versus RPM, we can see that this particular table here in our base calibration has already been maxed out. |
| 06:51 | So that's our recommendation there, that's what you're going to want to do with that particular table. |
| 06:57 | While we're on our torque management tab we're going to jump across and look at our driver demand table and this is a key aspect of a torque based ECU. |
| 07:06 | This defines our requested torque relative to our driver's foot pedal position and our engine RPM. |
| 07:12 | So those are the inputs for our table, we've got pedal position on the vertical axis, and we've got engine RPM on the horizontal axis, of course the numbers in the table are our requested torque values. |
| 07:22 | Now if we are modifying our engine, obviously we're expecting the engine to produce more torque and we do need to represent this in this table. |
| 07:31 | Particularly while we are tuning, we don't need to be too fussy with this, it doesn't need to be 100% accurate, but we do need to raise these values, otherwise if the calculated torque exceeds our driver demand value, then the ECU will simply close the throttle body. |
| 07:48 | Obviously that's going to limit the torque and power the engine produces. |
| 07:52 | Particularly with naturally aspirated engines, what we want to do is focus on the bottom of this table where we are at or close to wide open throttle. |
| 08:01 | And depending on the modifications you've made of course you may want to raise the values here by perhaps 10% to 20%. |
| 08:08 | And we can do a little bit of interpolation in this table to make sure that it remains nice and smooth. |
| 08:14 | We don't need to be too fussy right now, we can come back and populate this table a little bit more accurately once we've completed our tune and we've got actual solid data off our dyno. |
| 08:23 | Obviously in our case when we're adding forced induction to a naturally aspirated engine, we're going to need to make much larger changes to our driver demand table. |
| 08:33 | And of course again here we're working with a calibrated table that comes from that Roush calibration value so we can see that down here we've got maximum values sitting around about 930 to 935 newton metres. |
| 08:47 | Moving on from our driver demand table, we're going to pop across to our torque model tab and this time we are on our general tab under torque model. |
| 08:57 | Here we've got a range of engine torque tables as well as inverse torque tables. |
| 09:03 | These are all based on the mapped point which we're going to discuss in a little bit more detail shortly. |
| 09:10 | But essentially these tables define the amount of engine torque that will produced relative to our engine RPM and load. |
| 09:18 | Let's click here on our engine torque for mapped point zero, and we see we've got our engine load on our vertical axis, and we've got our engine RPM on our horizontal axis. |
| 09:29 | Now if you're dealing here with a naturally aspirated engine then my recommendation would be to start by leaving these tables stock. |
| 09:36 | We are going to need data from our dyno to correctly calibrate them. |
| 09:41 | And while they won't be quite right for a modified engine, generally they're going to be close enough that it's going to allow us to get into the tuning process and get some hard data so that we're going to be able to properly calibrate them. |
| 09:53 | Now the engine torque tables work in conjunction with the inverse tables so we'll just open up our inverse table here, again for our mapped point zero, and we'll put them side by side. |
| 10:04 | So what we can see with our inverse table is that the vertical axis is now torque on newton metres and the numbers that are filling this table are our load values. |
| 10:18 | So these tables need to be calibrated correctly and just as importantly as that, once we've calibrated our engine torque table for a particular mapped point, the inverse table also needs to be calculated. |
| 10:31 | There is a calculator built into the VCM suite software that makes this very simple so it's not as scary as it sounds. |
| 10:40 | I'm not going to deal with this at this point because you'll see once we get stuck into the tuning, exactly how to go about this. |
| 10:47 | At this point we just need to know that these tables need to be manipulated. |
| 10:50 | One thing that is important to note here, particularly if we have a naturally aspirated calibration and we are adding forced induction, we are going to need to go through a procedure that's referred to as renormalising. |
| 11:03 | So we see here that our engine load axis, in this case goes all the way through to 1.6 or 160% if you like to think of it in those sorts of numbers. |
| 11:15 | So essentially here you could think of this as similar to volumetric efficiency. |
| 11:20 | So with a naturally aspirated engine, we're unlikely to see our load exceed 1.0 or at least not very far beyond that. |
| 11:28 | With a forced induction engine, we start moving beyond 1.0 in our load. |
| 11:34 | So with a naturally aspirated calibration we're going to find that the load axis for these tables as well as the spark tables will all max out at a load value of 1.1 So we need to adjust that load axis and then adjust the values inside of the table. |
| 11:51 | And we'll see how that's done here. |
| 11:52 | We can right click on the load axis and if we come down to row axis and click on edit, this will allow us to then adjust those particular values. |
| 12:02 | So what we want to do is essentially adjust the load axis so that it's going to cover the range that we're expecting our engine to operate in. |
| 12:11 | So in this case you can see that the calibration will allow us to run up to 1.6 or 160% in terms of the load. |
| 12:19 | This is going to be more than enough to cover the range that our supercharger is going to be operating in. |
| 12:24 | The problem with this though is that when we adjust our load axis, nothing happens to the numbers in this table. |
| 12:32 | So what I'm saying here is that if we adjusted the bottom value here in our load axis from 1.1 in a factory naturally aspirated calibration, to a value of 1.6 to suit forced induction we're still going to end up with the same values here in our bottom row. |
| 12:50 | The software doesn't do anything to adjust these values. |
| 12:54 | So what we need to do is take that into account and manually adjust these so that they are suited for that particular load value. |
| 13:02 | This becomes more important when we are looking at our spark tables, which we'll get to very shortly. |
| 13:08 | What we're going to do now is jump back across to our air flow tab and we're going to come to the general tab. |
| 13:14 | And we're looking at the information here for our mass air flow sensor calibration. |
| 13:20 | In particular here the ECU has the option of using an analog voltage based air flow meter, we can see that that option is available here, or a digital sensor, a digital mass air flow sensor, a mass air flow sensor versus period which is this particular ECU is using. |
| 13:37 | So if we click on this we can see we've got a two dimensional table for our MAF calibration. |
| 13:42 | This is the period versus our air flow. |
| 13:44 | We can look at this graphically as well, so it looks a little bit more sensible, more like what we'd expect from a mass air flow sensor curve. |
| 13:53 | One of the changes that we are going to make here before we move on is we're going to come down to our cylinder air anticipation. |
| 13:59 | The Ford ECU uses both the mass air flow sensor as well as a speed density subsystem. |
| 14:06 | And to start with, for beginning our calibration, we're going to want to calibrate the mass air flow sensor. |
| 14:12 | And for this to work without the speed density subsystem affecting it, we're going to go through and we're going to disable our cylinder air anticipation. |
| 14:22 | Moving down, we also want to set our cylinder air wide open throttle mulitplier as well as our cylinder air max multiplier to values of 1.9 These values are used to calculate the upper limit for the cylinder air mass calculation so we need to raise these to suit our engine air flow. |
| 14:42 | Now we're going to move across to our fuel tab and we're going to have a look at our power enrichment tab. |
| 14:48 | So we'll click on that here. |
| 14:50 | So our power enrichment essentially defines what our lambda targets are going to be when the engine is operating in what's defined as power enrichment mode. |
| 14:58 | Or in other words when we are at wide open throttle asking for maximum power. |
| 15:02 | Now first of all we need to look at what throttle position we need to exceed in order to move into power enrichment, click on that we can see at the moment we've got a really simple table, all of our RPM zones are the same here, they're all set to 6500. |
| 15:16 | So we can see that the values in this table are all set to 90%. |
| 15:19 | So essentially we're going to need to exceed 90% throttle in order to go into power enrichment. |
| 15:26 | It's not a great idea, particularly for a forced induction engine, because we're going to see positive boost pressure well below 90% throttle. |
| 15:33 | So we're definitely going to want to reduce those values down and this is also going to produce more part throttle torque as well, the engine's gonna produce more torque once we exceed that position. |
| 15:43 | There's a couple of ways we can deal with this. |
| 15:45 | What we can do is just make an across the board change to something in the range of 40%. |
| 15:50 | We make sure that this value is above our normal cruising area. |
| 15:53 | So we really do want to actually be asking for more power when we exceed this throttle position. |
| 16:00 | The other way we can go about this is to set up a proper two dimensional table with a proper RPM axis. |
| 16:05 | Now in order to do this we can right click go down to our row axis and set edit. |
| 16:11 | And we can set some sensible values in here. |
| 16:14 | So we'll go through and do that now. |
| 16:31 | Alright with a RPM axis now set, we can go through and adjust our pedal postion. |
| 16:37 | So generally here what we want to do is at low RPM our pedal position to enter power enrichment would be slightly higher, so we may set this somewhere around about 60% at low RPM, and as our RPM increases we're going to drop that, so let's go ahead and put some numbers into this table. |
| 17:07 | Alright so we've now got a table that is going to mean that we need to exceed 70% throttle down at 1000 RPM, but by the time we get above 5000 RPM, we're only going to need to exceed 25% in order to go into power enrichment. |
| 17:23 | Now that we know when our ECU is going to move into power enrichment mode, we want to actually look at the lambda target for power enrichment. |
| 17:30 | We've got two tables here, we've got one labelled wide open throttle lambda, we've got another one for flex fuel vehicles. |
| 17:37 | We're not running flex fuel so all of our work's going to be done here in our wide open throttle lambda target table. |
| 17:43 | You can see here we've got a three dimensional table. |
| 17:45 | We've got our engine RPM on our vertical axis, and we've got our coolant temperature on the horizontal axis. |
| 17:52 | So you can set this table to suit, and obviously we're going to be finding on the dyno what our optimal wide open throttle operating lambda targets are. |
| 18:03 | For the moment though, particularly while we are dialling in our mass air flow sensor, which is going to be our first job, we want to make sure that these are all set to a safe value and also something that is flat across the RPM range, so in this case I'm going to set everything here in this table to 0.8 lambda. |
| 18:20 | Of course if you're running a naturally aspirated engine, you could be significantly leaner than this. |
| 18:25 | Probably a good starting point would be somewhere around about 0.88 You don't need to be too precise here because we will be dialling in this table more accurately during the tuning process. |
| 18:36 | Alright we'll close down that table and we've got one more parameter that I want to mention while we are on this tab, which is our enrichment rate parameter. |
| 18:43 | Now this defines how quickly the air fuel ratio the engine's running at can ramp between our normal cruise target of lambda one through to whatever we've got in our wide open throttle lambda target table. |
| 18:54 | Now you'll see that this is currently set to 0.5 and that's already been increased from what you'd find in the stock naturally aspirated calibration. |
| 19:02 | I'm actually going to increase that further and we'll set that to 1.0 So this just allows our air fuel ratio to ramp richer a little more quickly. |
| 19:12 | Definitely important as well on a forced induction vehicle. |
| 19:16 | Next we're going to move across to our general tab and I just want to mention where we would be entering our injector data if we are swapping our injectors. |
| 19:24 | So we can see here we've got a range of parameters that are listed under injector control. |
| 19:30 | This is where we're going to be entering that data. |
| 19:31 | Of course our calibration here from Roush is already set up for the larger injectors fitted so personally we've got no work to do here. |
| 19:39 | And as we've already discussed, this data is essential to the correct operation of our ECU, we're not going to be able to fudge this data and expect to get good results. |
| 19:48 | So if you are purchasing larger injectors, make sure that you are purchasing injectors with the correct characterisation data that is supplied in the Ford format. |
| 19:58 | Next we're going to move across to our oxygen sensors tab. |
| 20:02 | We've already briefly looked at this when we were talking about how we can force the ECU into open loop control. |
| 20:08 | However there's one other parameter or set of parameters that may need some adjusting and this is our transport delay. |
| 20:13 | And this essentially defines how long it takes for the air fuel charge to exit the cylinders and then be registered by the O2 sensor. |
| 20:23 | So if we click on our transport delay table we can see that table. |
| 20:26 | This is a time delay relative to our load and our engine RPM. |
| 20:32 | If you have fitted a set of long tube headers which fits the O2 sensors further away from the cylinders than the stock manifold, you may need to increase the values of this table. |
| 20:43 | Now it's going to be difficult to be absolutely precise here but in general, multiplying this entire table by a value of about 1.3 is going to give you some numbers that will work for a set of long tube headers. |
| 20:56 | Now we're going to have a look at one of the more complex aspects of the Ford ECU which is the mapped points tables that we've already kind of touched on a little bit. |
| 21:06 | In order to understand these we're going to jump across to our air flow tab, and then we're going to want to have a look at our variable camshaft tab. |
| 21:12 | Now for a start it's worth mentioning here that under VCT mode we've got a few options. |
| 21:19 | Now you can see that in this particular application we have got dependent set as our option. |
| 21:25 | If we look at our drop down menu we can see we've got a range of other options. |
| 21:28 | For a quad variable cam engine, we're going to see this will be set to TI VCT. |
| 21:35 | A dependent actually makes our job much simpler here. |
| 21:38 | This is because the engine we are tuning here is a single overhead cam engine. |
| 21:43 | They do use variable cam control but of course with a single cam engine, then as we advance or retard the cam this is going to affect both the intake and exhaust valve opening and closing points simultaneously. |
| 21:56 | So this is greatly simplifying our work to do here. |
| 21:59 | However everything we are going to cover is still gonna cross over to the more complex engines from Ford as well. |
| 22:06 | Next we're going to have a look at our mapped points configuration option. |
| 22:11 | So we'll click on that here and we see that this opens up and shows us which of the available mapped points is currently being used. |
| 22:19 | So we can see that essentially we have 16 available map points from map point zero through to 14 and then we've also got a mapped point that's known as OP which is standing for optimum power. |
| 22:34 | So in this particular engine, we can see that the only mapped points actually being used are map points zero through to four, that's identified by the fact these little flags are all set to one. |
| 22:45 | So this means that we're actually only using five of the map point tables. |
| 22:49 | So that takes a lot of work away from us. |
| 22:51 | Still a little bit more to understand about this as well though. |
| 22:56 | If we now click on our intake valve opening and exhaust valve closing tables, we're going to see what our cam target position will be for each of our map points. |
| 23:07 | So let's look at our intake valve opening points. |
| 23:10 | And we can see again we understand that we are only using map points zero through to four, so we can see what our cam angle is going to be for each of those particular map points. |
| 23:21 | So we have zero through to 43 degrees of cam angle. |
| 23:25 | So this defines what our cam angle is gonna be based on, the mapped point that we're operating at. |
| 23:30 | Of course here we have our exhaust valve opening, cam target table is identical again for exactly the reason we've already discussed. |
| 23:38 | This is a single cam engine. |
| 23:40 | In a quad cam engine where the intake and exhaust cams are operated independently, obviously these tables would be different. |
| 23:48 | So now we know what the cam timing is going to be based on the current mapped point that the ECU is operating in. |
| 23:55 | But we also need to know how the ECU decides which mapped point to use, and how we can adjust that if we decide we want to. |
| 24:03 | So for a start the ECU has a variety of operating modes. |
| 24:07 | For example here we've got emission reduction, fuel economy, and optimal stability, and we've also got optimum power, although in this case, we would recall that our optimum power mapped point is disabled, so optimum power isn't actually being used here. |
| 24:24 | To decide which of the current operating modes is being utilised, there are a variety of load tables that define how the ECU will move between those different operating modes. |
| 24:36 | Now let's have a quick look at our emission reduction operating mode. |
| 24:40 | And we can see in this operating mode, the mapped point is always going to be zero. |
| 24:46 | The same goes here for our optimal stability and in fact the operating mode that the ECU in this particular calibration is going to spend most of its time in is the fuel economy mode so we'll open that up. |
| 24:58 | So now we can see the y axis of our y axis values here and which mapped point is going to be used for any of those y axis values. |
| 25:07 | In this case really straightforward, we can see it is just a direct correlation zero to zero, through to four to four. |
| 25:13 | Now the numbers in this particular table on their own aren't a lot of use to us so we'll close that down, these work in conjunction with a set of tables we've got down here below called distance tables. |
| 25:24 | Slightly unique name which doesn't necessarily help us with understanding how these tables work. |
| 25:30 | But we'll go through that now. |
| 25:32 | We've already defined that in the majority of the situations, this particular ECU will be working in the best fuel economy mode. |
| 25:38 | We'll open that up. |
| 25:40 | We see we've got a three dimensional table with load on our vertical axis, RPM on our horizontal axis, and then the numbers inside of this table correlate to the y axis values on the table we've just looked at. |
| 25:53 | Let's open those up together so we can see how they work. |
| 25:57 | Alright we'll just drag this across here. |
| 25:59 | So what we can see is that if we have a value of zero for example in our distance table at 2000 RPM and 0.6 load, we can see that that gives us our y value of one which we can then use our other table here for our mode for fuel economy and we see that a value of one in our distance table, means that we're operating on our mapped point one tables. |
| 26:27 | Things get a little bit more complicated in these distance tables where we've got values that aren't a whole number. |
| 26:33 | For example at 2000 RPM and 0.2 load, we can see that the value is 2.5 Now what this means is that we are operating between, and exactly in between, in the middle of mapped points two and three. |
| 26:48 | So the ECU will be interpolating between the mapped point two and mapped point three table. |
| 26:53 | So let's see how we can use that information to find out what our cam target would be with a mapped point of 2.5 We'll close down these tables, we'll go back to our intake valve opening table. |
| 27:07 | We'll remember that we are operating between map points two and three. |
| 27:11 | We can see that at map point two, we've got a cam target of 23 degrees, and at map point three we've got a cam target of 33 degrees. |
| 27:18 | We're exactly in between, so when we've got a value of 2.5 in our distance table, this would mean that we have a cam target of 28 degrees. |
| 27:27 | Now those distance tables also define how the ECU will move between the other map point tables. |
| 27:34 | So for example this defines which mapped point we're using for our spark advance, and also our torque tables as well. |
| 27:41 | So the way the Ford ECU deals with these mapped points is a little bit complex and it does take a little while to get your head around. |
| 27:48 | Of course we've looked there at our cam target. |
| 27:52 | The mapped point will also affect our torque tables that we've already looked at, it will also affect our spark tables which we're going to look at shortly. |
| 28:03 | The real key to understanding this it to go through the process of first of all understanding the mapped points configuration. |
| 28:10 | Remember this defines which of the available map points will actually be used. |
| 28:15 | Once you've gone through that, you'll also need to understand the cam targets versus each of those map points, so that we know what cam target will be used depending on which mapped point the ECU is operating in. |
| 28:29 | Understand on top of this that there are a variety of engine operating modes that the ECU can move between. |
| 28:37 | So we need to understand which of those modes is active and which mode is being used at any particular time. |
| 28:44 | Obviously in our example this is simplified because it's always running in our fuel economy mode. |
| 28:49 | Finally once we've got that under control we then use our distance table for the mode the ECU is operating in, in order to define which of our mapped points is being used. |
| 29:01 | So we'll see as we get into the tuning though that this really isn't as complex as it sounds and we can also scan to find out which of the tables, which of the mapped points is being used at any particular point. |
| 29:15 | Now that we're got a better understanding of our mapped points and how these work, we can move on and look at our spark tables, so let's head across to our spark tab. |
| 29:25 | And there are a variety of tables here, a lot of our work is going to be focusing on our borderline tables which are here. |
| 29:32 | These also work in conjunction with our MBT tables which you can see right here. |
| 29:38 | Of course we've got a table for each of our mapped points. |
| 29:40 | Now the MBT tables, as their name would suggest, these tables are defining the minimum timing for best torque, or maximum brake torque timing, whichever way you wanna look at that. |
| 29:52 | And in most instances, these won't need any adjustment. |
| 29:54 | We do need to make sure however, that the numbers in the MBT table are at least as great as the numbers we're targeting in our borderline table. |
| 30:03 | Now these MBT tables are used as part of Ford's torque calculation model and essentially it uses the distance from MBT for our current operating point, to calculate what the likely torque output is. |
| 30:17 | So most of our tuning is going to be done inside of our borderline spark table. |
| 30:23 | So let's have a look at these now. |
| 30:26 | So we'll bring up our borderline spark table for map point zero. |
| 30:30 | And we can see here, I've actually gone through and I've set our load axis to what we'd expect to see from a naturally aspirated engine. |
| 30:39 | Here we can see this only goes out to 1.1 So I just want to show you in a little bit more detail, that process of normalising these tables after we have made adjustments to our load axis and how that works. |
| 30:51 | So let's bring up another table here, we'll bring up mapped point 13, and we'll put these side by side. |
| 30:57 | So we can see that we've got at the moment exactly the same values in both of these tables and I'm just going to use mapped point 13 just as a little example of how we can go about normalising the table. |
| 31:08 | So the first step of course is that we want to right click, go down to our row axis and we want to edit that axis. |
| 31:15 | And what we're going to do is adjust this axis to cover the range we're likely to be running in. |
| 31:20 | So we'll go all the way out to 1.6 and we'll just adjust this axis down now. |
| 31:30 | Alright so we've got an axis set up now that's going to suit forced induction. |
| 31:34 | We've left everything from a load of 0.7 and below untouched, but we've now expanded out the upper end of our load axis, so this still gives us really good resolution down in the cruise, light load areas of our table. |
| 31:49 | Now when I close this down what we can see is that the load axis has changed but the numbers stay exactly the same. |
| 31:57 | So in other words, the timing values that we saw over here from our original table that suited a load of 1.1 are now applied out at a load of 1.6 so out quite high in the boosted areas of our map. |
| 32:13 | Clearly this isn't what we're going to want so we need to do a little bit of work here. |
| 32:18 | So the first step is to copy the rows that still correlate. |
| 32:22 | So what I mean by this is we can see here we've got a load row from our original table, with a load of 1.0 and we've got the spark values for that load row. |
| 32:33 | If we look now though at our load row of 1.0 with our new load axis, we can see that at 6000 RPM and a load of 1.0 we've now got spark timing of 30 degrees, whereas from our previous table, our original calibration, this is 26. |
| 32:49 | So just simply by adjusting that load axis we've ended up advancing the timing and that's probably not what we're going to want to do. |
| 32:56 | So what we want to do here is basically copy and paste the load cells that we can. |
| 33:02 | So in this case I'm taking our original data from a load of 1.0 I can just highlight that column by clicking on 1.0 Using control C we'll copy that data, and I want to click in our new table, in the same load zone, control V and we'll now paste that value. |
| 33:17 | So we know that we didn't change anything at 0.7 so if we look at our values at 0.7 and we look at our values in our original table at 0.7 we can see that these all match. |
| 33:30 | So we've got a little bit of work to do now as we move out into the positive boost areas of our table. |
| 33:37 | And at this point with no data, we're going to have to take a bit of a guess at this. |
| 33:42 | So I'm just going to paste the values that we've just made down, and what we can do is start with something relatively conservative. |
| 33:49 | We're going to end up removing four degrees per load zone as we move up. |
| 33:55 | So again we'll just copy that, and from 1.2 using control C. |
| 33:59 | Control V we'll paste it into our 1.4 load zone. |
| 34:03 | And again we can remove four degrees, copy that, down to 1.6, control V. |
| 34:10 | And again we can remove four degrees. |
| 34:13 | So this is the sort of process that we go through. |
| 34:16 | Of course the numbers I've set up in that table may or may not be right. |
| 34:20 | You can use your own discretion to set up a spark table that's going to be suited but that important process of adjusting the load axis and then normalising that table by copying back the load points from our original table so everything still makes sense. |
| 34:35 | So once we've got our load zones set up, we want to go through and make sure that each of our tables has numbers in it that are going to be sensible. |
| 34:43 | In a lot of instances if we are working from a base tune, we can leave these spark tables as they are for the moment because we're going to be looking in a little bit more detail about how we can calibrate those as we get further into our process. |
| 35:00 | Now it is important to understand that the borderline table that we've just looked at is only a base table for our spark and there are a range of modifiers that will adjust the final ignition advance being delivered to the engine. |
| 35:12 | If we move down, we can see that we have some modifiers here. |
| 35:17 | For a start we'll look at our fuel modifier, in this case our lambda modifier and what we can see in this table is that as our lambda target becomes richer, we see that this table adds timing, particularly if we were targeting 0.75 lambda for example, at 3000 RPM, we see that 1.9 degrees of additional timing is being added in. |
| 35:42 | Now the way you deal with this table is completely up to your own personal preference, you can leave the factory values in there and just understand what they are doing. |
| 35:50 | Or alternatively you can zero this table out and do all of your tuning within the borderline spark table. |
| 35:57 | I'm going to leave this table as is, and it's just important to understand that it is sitting there working in the background. |
| 36:04 | We'll close that down, we also have some adjustments here based on our intake air temperature and our engine coolant temperature. |
| 36:12 | Let's have a look at our intake air temperature modifier. |
| 36:15 | And we can see that in this case if our intake air temperature reaches 93 degrees centigrade, the ECU will be pulling out minus 90 degrees. |
| 36:27 | Now that sounds pretty over bearing. |
| 36:31 | But we don need to understand that this table also works in conjunction with a multiplier table. |
| 36:37 | So we'll just open that up as well, and we'll look at these side by side. |
| 36:41 | So what we need to understand is that the multiplier table is a three dimensional table, we've got our load on our vertical axis, and we've got our engine RPM on our horizontal axis. |
| 36:52 | So in order to find out what amount of our correction is being applied, we need to look at our correction and then multiply this by the multiplier value. |
| 37:04 | Let's just bring up our calculator and we'll go through that exact process. |
| 37:08 | So let's assume that we are operating at 93 degrees. |
| 37:11 | We know that our correction factor there is 90 degrees, removing 90 degrees. |
| 37:17 | But let's also assume that we are operating at 4000 RPM and 0.75 load. |
| 37:24 | So we see the multiplier in there is 0.105 So what we can do then is multiply our correction by 0.105 And we can see that this in effect removes 9.45 degrees. |
| 37:39 | So nothing as dramatic as it initially sounds. |
| 37:42 | We'll close all of that down now. |
| 37:44 | If we look at our engine coolant temperature correction, we can see that this operates in exactly the same way, we've got a multiplier, or a correction factor, and a multiplier table. |
| 37:56 | So exactly the same as what we've just looked at. |
| 37:59 | Moving across we'll also look at our cylinder pressure limit table. |
| 38:04 | Now again this table is modified, this becomes a limiting table on the maximum amount of advance that will be delivered, versus load and our engine RPM so we can see in this case the table is maxed out. |
| 38:19 | So it's not gonna have any effect. |
| 38:21 | But it is important to check this table out and just make sure that this isn't going to be lower than the timing you're trying to deliver, otherwise the engine wont' end up with the ignition timing that you're expecting, and it can be a little bit confusing trying to figure out why that's the case. |
| 38:38 | While we're on our spark tab, there's one more parameter that I just want to mention which is our global spark adder. |
| 38:44 | And as its name suggests, this is just an overall trim that is applied to the final ignition timing being delivered to the engine. |
| 38:51 | It's a good idea, particularly when we're just getting started, to remove a little bit of timing using this global adder, so I'm just going to take two degrees out there. |
| 39:00 | We are gonna use this to remove some timing to safe up our tune while we're getting started, we do need to make sure we remember that we've done this so that we can remove that adder later on. |
| 39:10 | Next we're going to move across and we'll have a look at our spark retard tab. |
| 39:15 | There's a few aspects we'll need to deal with here. |
| 39:17 | We'll start by having a look at our max retard table and this defines the maximum amount of ignition retard that can be removed. |
| 39:25 | As you can see, we've got a three dimensional table here relative to load and RPM which we can adjust. |
| 39:30 | In this case you can see globally this table is set to minus four degrees, so the maximum amount of ignition timing the ECU can pull out is four degrees. |
| 39:39 | That should be ample providing that we have done our job correctly and the borderline spark advance tables are correctly set. |
| 39:47 | So in our instance, I'm going to leave that alone. |
| 39:50 | Another aspect we're going to look at here is our max advance table. |
| 39:53 | And an interesting of the knock control strategy in this ECU, the ECU can advance as well as retard the timing. |
| 40:01 | So if the ECU is detecting no knock activity then the ECU is able to advance the timing as defined by the values in this table. |
| 40:10 | Now this table really comes down to your own personal preference. |
| 40:14 | I'm going to leave it set to the values we see here. |
| 40:17 | Alternatively you could highlight the entire table, zero out these values. |
| 40:21 | And then you know that the ECU is not going to be able to advance the timing beyond whatever you've got in your borderline spark advance tables. |
| 40:29 | The next aspect we're going to look at here is our recovery. |
| 40:32 | So we've got two tables here for rate fast and rate normal. |
| 40:36 | So these define how quickly the retard is removed once the knock has stopped. |
| 40:44 | And in the factory calibration the rate that the retard is removed is incredibly slow and we've seen a situation where knock that was active right at the very start of a ramp run here on the dyno takes an entire 10 second ramp run to decay away. |
| 41:03 | So one aspect where we can get some really good improvements in our performance is by adjusting these tables. |
| 41:09 | The way that these tables work is that smaller numbers will remove the ignition retard quicker and larger numbers will remove it more slowly. |
| 41:18 | So what I'm going to do is just make a broad across the table change here and we're going to multiply the values in the table here. |
| 41:26 | This is our fast retard rate table, we're going to multiply that by 0.5 We're going to then bring up our normal table and we can see the numbers in our normal recovery table here are quite a lot larger. |
| 41:40 | So what we're going to do is highlight that particular table there and we will multiply this by 0.25 so essentially we're dropping those by a quarter. |
| 41:49 | Of course these broad adjustments that I've just made are only a starting point and we can further modify these tables once we actually start getting some data and running the car on the dyno. |
| 41:59 | Let's head across now to our air flow tab, and this time we're going to be working on our speed density tab, so this is the parameters that define the speed density subsystem used in the Ford ECU. |
| 42:11 | Now there's a couple of aspects that we're going to want to change here. |
| 42:14 | We're going to start with our calculated map max. |
| 42:18 | We need to make sure that this exceeds the maximum manifold pressure that we're likely to be running in our car. |
| 42:26 | In this case because we are boosted, we do need to raise this. |
| 42:28 | So we can see we've got this set to 64 inches of mercury. |
| 42:33 | We also want to change our maximum air charge load value. |
| 42:37 | So in this case the calculation will only work up to 1.0 So I'm going to extend that out to 1.6 The other two adjustments we need to make here is to our map max delta table. |
| 42:51 | We want to make sure that this basically follows our boost curve and we wanna make sure that the values in this table are always slightly above the boost pressure that we're expecting to see. |
| 43:03 | Likewise we'll come down to our map max versus air mass. |
| 43:06 | And in this case we want to again just make sure that all of these values are above the boost pressure that we're expecting to see. |
| 43:13 | So we've got these all set to 64 inches of mercury. |
| 43:17 | It's important to understand here that these are absolute values as well, so a value of 30 inches of mercury is essentially the same as approximately 15 psi of positive boost pressure. |
| 43:29 | OK so we've got to a point now where we've made all of our base adjustments to our calibration. |
| 43:34 | We've got our calibration set up ready to go, we want to make sure that we save this, and we're ready to move on with the next step of our process. |
