Practical Standalone Tuning: Step 7: Steady State Fuel Tuning
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Step 7: Steady State Fuel Tuning
49.06
| 00:00 | - Alright the next step of our 10 step process is to complete our steady state fuel tuning and I'm just going to run through what we're planning on doing. |
| 00:08 | I'll demonstrate a few columns or a couple of columns of this live explaining what I'm doing and then we'll speed up the rest of the process a little bit, just so that we don't end up taking forever on this worked example. |
| 00:19 | Essentially once you understand the process we're going through it's a bit of a rinse and repeat and it is a slightly time consuming process. |
| 00:26 | So just to cover off the intention here, what we're going to do is start at essentially the lowest RPM we can access on the dyno and we're going to start it at the lowest throttle that we can use to actually hold the engine in steady state on the dyno. |
| 00:41 | And we're going to be then tuning from that low load region and we'll slowly start increasing the throttle as we tune the cells, basically moving us, in this case, down the columns in the G4X fuel map so let's have a quick look at that. |
| 00:56 | So let's say we'll start probably at 2000 or 1500 RPM, we might be able to get ourselves down to maybe -50, -60 kPa so it'd be a case of tuning these cells and then we'll obviously be moving down the column here, filling in as we go. |
| 01:14 | Now a couple of things that are worth mentioning here, first of all there are multiple ways that we can make our tuning changes. |
| 01:22 | So it's important to sort of understand what our options are, I'll cover off those briefly. |
| 01:26 | So let's just go out to a cell here that we aren't really interested in at the moment. |
| 01:31 | So 40 at the moment in that particular cell and the first option we've got here is that we can just manually enter a value. |
| 01:39 | So for example, 35 and the enter key, obviously that's going to make that change. |
| 01:43 | If we're a long way from the mark, that's actually not a bad way of making the tuning change that we want. |
| 01:49 | Obviously quicker than using the shift q or shift a keys to make those changes. |
| 01:53 | Once we get closer, that's typically what I will do though. |
| 01:56 | Shift a, obviously down by 0.5%, it's a coarse adjustment, the a key on its own, down by 0.1%. |
| 02:02 | Conversely shift and q, up to 0.5% and the q key on its own, up by 0.1%. |
| 02:09 | Other option we've got is to make math changes. |
| 02:13 | So for example, we might want to add five. |
| 02:16 | Well what we can do is hold down the shift key, press the plus key and enter five. |
| 02:20 | And it will show you exactly what it's going to do here, it says it's going to add five, so what we can now do, press enter, of course that's exactly what it does. |
| 02:30 | That's useful for making block changes but typically not the way I will actually use the user interface and the shortcut keys. |
| 02:39 | Probably one of the changes I will make, and this is really handy if you are using our correction factor calculation that you'd have learned about in the EFI Tuning Fundamentals course. |
| 02:49 | Essentially if we have a lambda of 1.0 and we want a lambda of 0.95, for example, we're actually running a little leaner than our target, then we can use our calculation, lambda one, which is what we have, divide that by what we want, 0.95 and then that's going to give us a 5% correction that we can apply so for example in that case, let's bring up our calculator and we'll do exactly that. |
| 03:11 | And what we want to do is our lambda 1.00, obviously don't really need to enter the .00 but for the sake of completeness. |
| 03:20 | We'll divide that by 0.95 and that gives us our correction factor 1.05, 5%, 5.3% if we want to be really fussy so what we can then do is just apply that. |
| 03:32 | So selecting the cell we want to apply then shift and the multiplication symbol on the eight key and 1.05, there we go, we've added 5%. |
| 03:41 | Multiply by 0.95, we're removing 5% so that's a shortcut that I will use quite frequently, it's really really handy to have that one in mind. |
| 03:51 | Other way we can make changes though as well, is that we can copy a change out to another cell. |
| 03:57 | So let's say we've got our cell here at 0 kPa, 2500 RPM, and what we want to do is maybe tune or copy that ahead I should say so that when we get into that next cell, we're going to be there or thereabouts. |
| 04:11 | So what we can do is hold down the control key and I'll use the down arrow key here, you can see that that just copies that out. |
| 04:16 | We can also do this with a column or a range of cells that we've highlighted. |
| 04:21 | So again if I press control and to the right, that's going to make that change there so very easy to manipulate the values that we've got. |
| 04:30 | Just to clean this up a little bit, I'll put it back to how it is. |
| 04:33 | So that's the process we're going to go through. |
| 04:36 | Now I've mentioned this process of tuning from low RPM, low load and increasing. |
| 04:42 | I am actually going to do this a little bit out of order because you'll remember that we are running that traditional or injection time based fuel model and the numbers in this table, you'll also remember have that interaction with the master injector pulse width so while we can absolutely come back and make changes to that master injector pulse width value which if I remember correctly is still 13 ms, we can do that later but it can add some complexities around getting the fuel table dialled back in so I like to at least get ourselves in the ballpark there and what I'd like to do here is come up to maybe 3500 RPM, maybe 0-20 kPa just transitioning onto boost and just adjust that master and pulse width until we've got numbers maybe around that sort of 40-50%. |
| 05:27 | Obviously right now we do have numbers of 40% in there but of course we've got absolutely no idea if that's correct or maybe we're too rich, maybe we're too lean. |
| 05:36 | So let's go ahead and do that now, I'll get us up and running with our fans on and let us stabilise and we'll have a look at what our air/fuel ratio is. |
| 06:12 | Alright so we can see at the moment, our lambda's sitting at 0.84 on our dyno, our target's 0.92 so I could correct this, let's just shift and A key. |
| 06:31 | And we're pretty much on our target now with a value of 34%. |
| 06:36 | We'll come back down to idle where it's a little bit quieter and a little bit easier to speak. |
| 06:39 | So basically the long shot there is that we were a little rich. |
| 06:43 | I've managed to correct that at 20 kPa, 3500 RPM and get our number down to 34.5%. |
| 06:47 | It's probably a little low though so I'm going to make a change to our master injector pulse width in order to correct that so let's go ahead and do that now, we'll get to our master injector pulse width and have a look at that. |
| 07:01 | So you'll remember that we can get to that master injector pulse width via the fuel main menu so if we type escape and fuel main, or you can scroll through the options, you'll find that particular menu and I was right, our fuel main, master fuel I should say, wrong terminology here, 13 ms. |
| 07:18 | So at this stage I don't really know exactly the magnitude of change that is going to be required and it doesn't matter, we can fine tune this later but let's just take a bit of a guess, we were not too far off, 34.5%, I'm going to just make a change at the moment to a value of 10. |
| 07:34 | Now I've entered that but I haven't pressed the enter key so that hasn't take effect yet. |
| 07:38 | What this is going to do is potentially make the engine stall so we do need to be mindful of this. |
| 07:44 | It's not going to do any damage but we are going to have to correct our fuel table because as soon as I make this change, essentially we're now injecting around 30% less fuel for the same request from that fuel table. |
| 07:56 | So let's do that and if we watch our lambda on the dyno, at the moment we're sitting at 0.87, you'll see that take effect. |
| 08:03 | Yeah we're well lean now, 1.09. |
| 08:06 | OK but we can correct this without going through and individually adjusting the cells. |
| 08:11 | So the way we can do this, if we bring our calculator up. |
| 08:14 | And what we want to do is enter our original, so 13 ms, and divide that by our new which is 10. |
| 08:23 | It gives us a correction factor of 1.3 so what we need to is essentially add 30% to our main fuel table and that should, for all intents and purposes, get us back pretty close to where we were operating. |
| 08:35 | So let's highlight the entire table, we'll use our multiplication symbol, 1.3, press enter, we're still a little light here, 44.9 at 20 kPa. |
| 08:45 | So might be a little bit lower than I'd necessarily want so that's OK, again we're only taking a rough guess at this stage so let's go back to our fuel main and we can do that using our little previous menu button. |
| 08:59 | Let's take another two milliseconds out of that. |
| 09:02 | So we're going to have exactly the same effect, we go from 10 down to eight, sitting at 0.87 lambda at the moment, press enter and we see we go lean again. |
| 09:11 | Bring up our calculator. |
| 09:14 | And we'll go through exactly the same process, so 10 divided by eight, 1.25 so another 25% to our main fuel table. |
| 09:22 | And this is important to understand because we can therefore correct our overall fuel table at a later point once we've done the majority of our tuning, if we want to adjust out resolution and we don't have to go through necessarily and retune everything so enter 1.25, multiplication symbol at the start of that, press enter, might have gone a little too far, we'll see though 56.1% there at 20 kPa, 3500 RPM. |
| 09:47 | Just for the sake of completeness, let's get our fan up and running and we'll actually go back into that cell and just see how well that actually worked out. |
| 10:16 | OK we can see there, we're pretty close, we're sitting at about 0.93, our target was 0.91 at that point so we're pretty damn close so that's our first change there and it's always a good idea to just at least get ourselves in the ballpark there rather than working with resolution that's going to be really flawed from the get go. |
| 10:35 | So that's our first process done there. |
| 10:38 | Now the other element here that I just want to address while we're talking here before we get into our tuning is the fact that clearly it's a turbocharged engine. |
| 10:46 | And what we want to do while we're going through the steady state fuel and then in the next step, our steady state ignition tuning, is run the engine on the bare minimum, the lowest boost setting that we can which is of course our wastegate spring pressure. |
| 11:00 | As we get higher in the revs, it's unlikely I'm actually going to want to go all the way to wide open throttle and maximum boost anyway. |
| 11:07 | It's a case of just being a little bit sensible about the amount of load and temperature that we're placing on the engine and realistically we don't run under steady state conditions, wide open throttle with six or eight or 10 psi of boost anyway, the engine will obviously be accelerating so we want to tune the engine how it's going to operate and under those conditions we will be using ramp runs. |
| 11:30 | So it's just a case of being a little bit sensible but I might well extend up to maybe 20 and 40 kPa into boost anyway. |
| 11:38 | So let's make sure that our boost is going to stay under control and in order to do that. |
| 11:44 | we'll press the escape key and what I really want to do is just go to our wastegate duty cycle menu and just make sure that this table is filled with zeros which it absolutely is not so this would have been a huge problem. |
| 11:56 | We can see here that we're actually resting, 85% duty cycle at some points and particularly given the fact that we have swapped out the original bleed off style boost control solenoid for a three port solenoid, this would result in massive over boost which comes back to, you'll remember during our configuration we went to the extent of setting a map limit to make sure we weren't going to get ourselves into a potentially dangerous situation. |
| 12:24 | So that's OK, what we'll do is we'll just simply start by zeroing that table out, we'll press F4 to store that so that should make sure that we are not likely to run into any problems with the boost control. |
| 12:37 | Couple of other tables I just want to quickly touch on here. |
| 12:40 | We should have realistically covered this during our configuration but we're dealing with a base map here so not such a big issue if we're starting from scratch but still these two tables are worth spending a little bit of time on. |
| 12:53 | So the first of these, we'll just open the menu and what I'm going to do is type in warm for warm up enrichment. |
| 12:59 | And this has caught me in the past so it's worth checking out. |
| 13:03 | Want to basically make sure that there is no warm up enrichment being scheduled under what I'd consider to be normal operating temperature. |
| 13:11 | We can see at the moment we're sitting at 95° but I don't have the fan on in front of the car, it's probably a little bit higher than what we'd expect when the engine's at operating temperature on the open road at speed. |
| 13:22 | Probably I'd expect that to be somewhere in the low 80s. |
| 13:25 | And we can in fact see that this table doesn't have any enrichment at that value. |
| 13:30 | We do have a little bit of enrichment interestingly at 70*C. |
| 13:35 | I'm going to get rid of that, I'll just zero that out, just because I'd consider the engine to be at operating temperature at 70. |
| 13:42 | Now this in no way is a complete tuning of our warm up enrichment table. |
| 13:47 | As you'll know from our EFI Tuning Fundamentals course, we really can't tune this table until the rest of the fuel table is tuned so we would have to come back and have another look at this anyway but what I want to do is just make sure that I don't have any weird auxiliary enrichment going on under the operating conditions I'm going to see when I consider the engine to be up to operating temperature. |
| 14:11 | Like I say, this has caught me out in the past with different brands of ECU and you get some weird inconsistencies with your fuelling and you sort of chase your tail and waste a bunch of time. |
| 14:19 | Easy to check that now and make sure it's OK. |
| 14:22 | Right the other table that I will just quickly show you here is our intake air temperature correction table. |
| 14:29 | So intake air temperature fuel trim table. |
| 14:33 | And this is actually really nicely set up by Link in the default map. |
| 14:37 | So we have values of zero at 20°C. |
| 14:40 | And we're basically adding 2% fuel per 10°C as the temperature, the intake air temperature gets colder, obviously more dense and likewise as we move to the right here and our intake air temperature climbs, we're removing 2% fuelling. |
| 14:57 | What's also important to understand here is that the correction is not as extreme at closed throttle, we can see that we have our TPS as the input for this table. |
| 15:07 | So at this stage I really don't see a need to make any changes to this, like I say, Link have done a good job of this base table in the base map. |
| 15:15 | 2-2.5% fuelling per 10° is generally a pretty good place to be. |
| 15:21 | And then we can address that as our temperature changes once we've got our tune dialled in and just see if maybe this does need a small tweak. |
| 15:29 | Remember we are dealing with ideals but we're not living in the ideal world so really we want to give the engine what it actually needs. |
| 15:37 | Alright let's get back to our fuel table. |
| 15:39 | So as I mentioned, we will start here at 1500 RPM. |
| 15:43 | Now I would recommend that even when you're dealing with the fuel table and you do your steady state fuel tuning, I would suggest that you use audio knock detection. |
| 15:53 | We've got a conservative base map here for our ignition timing. |
| 15:57 | Knock shouldn't be an issue but we can never guarantee that so I would recommend that. |
| 16:01 | In our case I know I'm running on good quality fuel, I've already gone through and dummy tested this engine and because I am also presenting it makes it a little bit easier if I'm not using audio knock detection but don't think I'm taking a shortcut here. |
| 16:14 | Alright so the other element that's worth mentioning just before we get up and running is that right now, we're actually idling a little bit higher than we were previously. |
| 16:23 | Awkwardly we are kind of between zones because our idle speed is 900 which you'll remember we targeted so we're actually sitting between the 750 and the 1000 RPM zone so it's a little difficult to be precise with our changes. |
| 16:38 | So let's just see how we can address that. |
| 16:40 | We'll press X and what I'm going to do is, I could either add another column here at 900, seems a little bit over the top but what I'll do is I'll just change that 700 to 900 and we'll click OK and again it will as usual ask us if we want to interpolate. |
| 16:55 | We click yes, essentially that means that no change has been made, the engine will run exactly as it was so what I'm going to do is just get our idle tuning dialled in here. |
| 17:04 | And because, as we increase our vacuum we'll move up in this table, I know I should need less fuelling, what I'm going to do is highlight all of the cells above as well, we'll just press shift and A and we'll just give our dyno a chance for the number, the lambda reading to stabilise and we'll get ourselves down to 0.95, 0.96 which you can see is our target and we're pretty much right there. |
| 17:30 | Important when we are looking at our targets as well, not to beat yourself up too much. |
| 17:34 | This is not a black and white process. |
| 17:39 | The air/fuel ratio, the lambda will always be moving around, so generally, particularly at idle or cruise, we're not worried about engine reliability so much. |
| 17:47 | If I'm within +/- about 0.01 lambda, I'm going to be pretty happy with that. |
| 17:53 | So we're 0.95 at the moment, pretty good. |
| 17:55 | So what we may find as we move out to 1500 RPM, because we don't really have a clue what those numbers are likely to be, we may find that initially we're a bit lean and we may need to add a bit of fuel just to get the engine to even run there. |
| 18:09 | We're going to give it a go though and see how we go so let's get ourselves up and running and we'll look at our first cell. |
| 18:17 | OK so we're up and running here, didn't actually require too much additional fuel or any changes realistically. |
| 18:24 | We can't expect the engine to necessarily run perfectly at this point while we're getting started but we can see here, we're a bit lean, 1.03 to 1.1, the lowest I can really get in the load there is around about -50 kPa so another shortcut I didn't mention, we press the space bar, that will jump us to the current active cell. |
| 18:44 | So our target there's essentially lambda one and we are a little bit lean so what I'll do is just use the shift and Q key to add a little bit of fuel. |
| 18:54 | Again, we want to make sure that we are right in the centre of the cell. |
| 18:59 | It's a little tricky here because we're right on the limit of the dyno's ability to essentially hold the car so once we add a little bit more load, it's going to be pretty much plain sailing. |
| 19:10 | So we've gone up to a number of 50 there. |
| 19:13 | Just get ourselves back in that cell, we are moving around a little bit. |
| 19:19 | Give ourselves a little bit more fuel. |
| 19:26 | And we're pretty good there, 0.99 lambda. |
| 19:29 | OK so before we increase, we just have anyway, we've only got a 10 kPa buffer at that point. |
| 19:35 | Before we increase the load, what we want to do is be a little bit sensible here and if we've got a value of, let's come back to idle while I'm talking about this. |
| 19:43 | Got a value here of 52.3% at -50 kPa and we've got now a value of 43.1% at 40 kPa, -40 kPa. |
| 19:56 | Chances are that the value at -40 kPa is going to want to be at least 52.3%, most likely a little bit more. |
| 20:06 | As we add load, the volumetric efficiency of the engine's going to hopefully improve and we would expect to see this step up a little bit. |
| 20:12 | So what that means is while there's no danger in it, as we move from -50 to -40 kPa, if I don't make any changes ahead and take a bit of a guess at what's likely to happen, we're almost certainly going to be lean. |
| 20:25 | Again not going to be damaging the engine but it's good practice just to take a bit of a guess ahead so what I might do here is enter a value directly of 55%. |
| 20:32 | The other option I could have done is gone for the cell I've just tuned, 52.3%. |
| 20:37 | Control and the down arrow and that's going to copy that ahead and then I can just use the shift and Q key a couple of times and add a couple of percent. |
| 20:46 | Alright let's get ourselves back up and running in that -40 kPa cell and just see how that's worked out. |
| 21:01 | OK so you can see our guess there still wasn't enough, we're still actually quite lean. |
| 21:05 | 1.04, 1.05 so again I'll just make sure I'm central in that cell. |
| 21:11 | Add a couple of percent using our shift and Q key, just gone a little too far so I'll bring that back and I'll make sure that everything's nice and stable there. |
| 21:22 | Actually, now that it's settled, it's gone a little bit richer again. |
| 21:26 | Alright 0.99, lambda 1.0, pretty happy with that. |
| 21:29 | So again what I'm going to do is just control and down arrow, done it twice, we only needed it once, let's just increase our throttle opening here and we'll come up to our -20 kPa cell, again pressing the space bar will get us into that cell. |
| 21:44 | And you can see that actually that one is pretty much on point, we're just very slightly rich so shift and the A key, we're targeting 0.98, 0.99 and we are 0.97, 0.98, I'm happy with that. |
| 22:00 | Again because I actually managed to copy that down twice, we'll just increase our throttle opening again, come up to our 0 kPa cell. |
| 22:09 | Again just making sure that we're central with every cell before we actually commit to making a tuning change, or at least as close as we can. |
| 22:17 | Target now is 0.95, 0.96 so we're just a touch on the lean side. |
| 22:22 | So I'll just add 1% fuel there, maybe another 0.5% and we're on the money there. |
| 22:28 | So now we're going to move from 56.3%, we're going to move into positive boost now, 20 kPa, at this point because we're not really going to be able to generate a huge amount of boost at 1500 RPM, I'm actually pretty comfortable going all the way to wide open throttle or seeing what we can get to so let's just see how far we can get. |
| 22:47 | You can see there, I am at wide open throttle now and we're basically sitting at 10 kPa, we're right between the 0 and 20 kPa cells. |
| 22:57 | Let's look at our fuelling, we are rich so what I'm going to do is just use the control key and the down arrow key, again I've managed to press that twice but that's OK. |
| 23:08 | And that gets us into our 20 kPa cell, now our lambda's 0.94, targeting 0.93 so let's just use the shift key, add a percent fuel and our job's done. |
| 23:19 | Alright let's come back to idle and look at our results. |
| 23:25 | Alright so it's a pretty narrow column that we were able to tune so we were only able to get down to -50 kPa and that's not uncommon. |
| 23:36 | And we were only able to get up to 20 kPa so again, 1500 RPM, wasn't really expecting too much more. |
| 23:43 | So we have got a good improvement there though so what we can do is take a little bit of note of what we're doing. |
| 23:50 | So first of all, while we couldn't get up to 40 kPa here at 1500 RPM, particularly as we increase the engine speed and there's more energy available to drive the turbo, we can expect our boost to increase so we'll get down lower in that table so again just a little bit of common sense and tuning ahead, we can help our situation. |
| 24:08 | So if we look at the column at the trends here, gone from 0 kPa, 56.3, we've added 1% for a 20 kPa jump, gone to 57.3. |
| 24:18 | Chances are with another 20 kPa, probably we're going to be at least another 1% so what I'm going to do is just control and down arrow key and then I'll use the shift and Q key and that's added 1%, I'm actually going to try and overestimate here, or add another percent as well and then for the sake of completeness, while we won't be able to get to it, I'm also going to copy or extrapolate those values down and we may even want to go to the extent of then highlighting those and adding another couple of percent there. |
| 24:51 | Likewise we haven't been able to really do anything with these lower load areas at the moment but again we can sort of extrapolate the trends that we're seeing. |
| 25:02 | So here we've gone from -40 kPa, 54.8, we've essentially removed two and a bit percent there, 2.5% as we've gone down to -50 so what we can do is kind of extrapolate the trend that we're seeing there into those untuned areas. |
| 25:20 | So we've got another 10 kPa change so I'm just going to underestimate here and I'll use the shift and A key to remove 2%, not 2.5 and again we'll copy that down, we're looking at another 10 kPa change so another 2% out of that. |
| 25:37 | Another 10 kPa, moving to -80, take another 2% and then finally from 80 to -100, we've now got a 20 kPa so what we can do now is use the math function, the minus symbol, -4, job done. |
| 25:51 | Now admittedly, those guesses that we just took are almost certainly not going to be perfect but they're going to be at least close and because we can't get to those zones on the dyno, it sort of becomes less important because we'll also struggle to get to them on the road but under certain circumstances we can get into some of those zones so this is an area that we will need to address once we road or track test this vehicle. |
| 26:16 | Alright so now we've got our full column complete there at 1500, what I'm going to do is just click at the top of that column, we'll hold down the control key, right arrow key and that just copies that out to 2000 RPM. |
| 26:29 | But as we move from 1500 to 2000 RPM, we could rightly expect an increase in volumetric efficiency so just to guess ahead a little bit, what I'm going to do is add let's say 1.05, 5% more fuel at 2000 RPM. |
| 26:43 | That might not pan out to be correct but it should at least get us in the ballpark so let's get ourselves up and running at 2000 RPM and what I'll do is I'll start by getting us to maybe 0 kPa, maybe -20 and we'll look and see how close that 5% guess is and then we'll make an across the board change for that column if we're not right so let's get up and running now. |
| 27:22 | Alright so we're operating at 2000 RPM, 0 kPa. |
| 27:25 | We can see that our target on the G4X software, 0.95, we're actually running at 0.98 so we're a little bit leaner so again just clicking at the top of that column, cause I had selected a single cell, what we'll do is use the shift and Q key and we will add 1% to the entire column. |
| 27:46 | 0.96, we're close, let's add one more % and see how that works out. |
| 27:51 | Alright we're on the money now. |
| 27:53 | So the theory here is that if we're lean at 0 kPa or rich at 0 kPa for example, we should probably rightly be lean or rich in the rest of that column. |
| 28:02 | So now what we'll do is we'll drop our throttle position down and see how close we, how low we can get in that column and I'm guessing again, can't quite get down and hold -40 kPa, but we certainly can hold -50 so let's get into that centre of that cell. |
| 28:23 | Again just making a little change to the dyno to get as accurately into that cell as I can and we can see that we're actually 0.91 so the theory hasn't worked out perfectly in this case. |
| 28:34 | Let's just close our throttle down a little bit and we'll see how close we can get to our -60 kPa, not quite, what I'm going to do here is I'm going to make this change to the -50 kPa cell as well as the ones at lower load which in this case of course is above, I've highlighted everything here and I'm just going to use the shift and A key to reduce our fuelling and take a couple of goes at that, we're getting close. |
| 29:03 | Alright 0.98, pretty close now, give it another 0.5%, 0.99 I'm happy with that. |
| 29:09 | And I'll just reduce the throttle here a little bit and we'll skirt through that -60 kPa cell before the dyno slows down. |
| 29:15 | So if I'm careful with this, gives us a chance to look at that -60 kPa cell and looks like we're actually a touch lean there so again, can't hold ourselves in the centre of it but I'm just going to add 1% back into that. |
| 29:30 | Alright so now we've got our -50 kPa and below cells dialled in, just have another check on our -50 kPa cell, making sure of course, again we're in the centre, yep we're looking pretty good. |
| 29:42 | So we'll repeat that process, let's come up to -40 kPa, little bit more throttle, staying nice and stable in the centre of the cell, 0.94, just reduced our fuelling using that shift and A key is a nice quick way of doing so. |
| 29:58 | Usually a couple of iterations of this depending how far out of the ballpark we are and 0.99, again I'm close enough to be happy with that. |
| 30:06 | Come up to our -20 kPa cell. |
| 30:10 | And again just a little bit rich but not too far, given that our target lambda has actually started to change now, we're sitting at 0.98, 0.99. |
| 30:23 | So we're happy with that, let's come up to 0 kPa which should still be correct because we did correct this. |
| 30:30 | Pretty good, 0.96 whereas we're 0.95 so let's go and just add 1% into that, happy days. |
| 30:36 | Now we're in the situation where we haven't tuned beyond this so chance are we should be OK because of what we copied from 1500 RPM but remember we could only barely get up to 10 kPa so we've got 62.1 and 62.2 at 0 and 20 kPa. |
| 30:56 | I'm going to guess that we might be a little bit lean if we can get into 20 kPa, I'm not worried about it though, let's just prove that point. |
| 31:03 | And almost full throttle, no actually only 50% throttle, 62.2, not too bad, we're 0.94 for a target of 0.92 so let's add a couple of percent of fuel which we probably could have guessed just based on the trends. |
| 31:19 | Alright I'm happy with that, let's see if we can get into -40 kPa, now at full throttle and I absolutely can't so we can't go any further than that. |
| 31:27 | Let's stop, come back to idle and we'll discuss our results. |
| 31:35 | Alright so the highest we could really get is just a little bit above 20 kPa here but again I'm going to apply the same sort of technique so we've gone from, in round numbers let's call it 62 to, in round numbers 64. |
| 31:50 | So we've essentially added there, 2% fuel or maybe a bit over 1.5%. |
| 31:56 | And I'm going to copy that out to our next cell as well, even though we couldn't get to it. |
| 32:01 | So again, control and down arrow from the 20 kPa cell and then we can use the +2 function and we're going to do that again and +2 to our 60 kPa. |
| 32:16 | Even though we can't get to it at 2000 RPM, just going to be helpful when we move across to our 2500 RPM column. |
| 32:24 | So again, we'll highlight our entire 2000 RPM column, control and the right arrow key and again, we're just going to guess ahead at a 1.05 multiplication factor. |
| 32:34 | That actually didn't prove to be too bad as we went from 1500 to 2000 so hopefully the same is going to happen again. |
| 32:42 | So we're going to go through and repeat this process, I will speed this up a little bit now because it is just a rinse and repeat of what you've already seen. |
| 32:51 | What I will just point out, is that even in that last little test, doing 2000 RPM, we did end up, as I backed off with our coolant temperature, getting a little high, I think I saw that spike to about 103. |
| 33:05 | This isn't uncommon sometimes with cars on a dyno, airflow can be problematic so it is something we're going to have to watch and monitor and chances are we're going to need, particularly as we get higher in the RPM, to come back and allow everything to sort of cool down and stabilise again. |
| 33:22 | So from here we're going to do the 2500 RPM column, I'm going to do this all the way out to 4500 RPM. |
| 33:28 | As I mentioned, despite the fact that we can probably get up to between the 60 and 80 kPa cells at wastegate boost, probably going to limit what I do here under steady state conditions to the 20 and 40 kPa cells and we'll be doing the high boost wide open throttle operating area under steady state conditions. |
| 33:50 | So let's get ourselves back up and running at 2500 RPM. |
| 42:48 | Alright we've completed our steady state tuning out to 4500 RPM and through the process of this I just wanted to discuss a couple of things that I did that may not have been apparent while I was doing it. |
| 43:00 | So I'm going through that same process I've talked about where I'm basically noting the trends that I'm seeing and trying to tune ahead where possible so in other words if I'm starting to see numbers that are going down as I increase the load, then I'm going to address those before I increase the load, increase the throttle position, end up in a situation where I'm potentially lean. |
| 43:21 | Now that's not a big issue at lower loads, lower RPM, but as we get higher in the load and RPM, this can potentially be dangerous. |
| 43:30 | So it's a good habit to get into just, it's always nicest and safest to be starting from a situation where we're potentially a little bit rich and also, while we're not talking about ignition timing, a little bit safe with our timing, retarded with our timing and then we can sort of start optimising our tune from there, rather than getting into a cell and finding out what we're already too lean and potentially the engine is over advanced knocking, that's the worst case scenario. |
| 43:55 | Now we talked about using that 1.05 or 5% multiplication factor to add fuel as we move into these untuned columns. |
| 44:02 | What I'm doing though is that's not a number that's set in stone, you don't have to stick to that so I was using a bit of common sense here, 5% for the most part tended to be a little bit over the top, a little bit excessive so I pulled that back and added 3% and that actually seemed to be pretty close and hopefully that you could also note is that through this process of copying these columns out, adding fuel, when I got into some of those higher loads, 20 and 40 kPa sites at 4000 and 4500, it was absolutely spot on or within probably 1% of target without me needing to make any changes and that's the beauty of the strategy. |
| 44:38 | It speeds up the tuning process and it also just as importantly, maybe more importantly, makes it safer on the engine. |
| 44:44 | Our job's not quite complete at this stage though, we've obviously got this rather large area of the map from 5000 RPM and above that we absolutely haven't touched yet and we also really haven't done much of anything down here in this lower load area so we're going to address both of those now. |
| 45:03 | Now again, just to reiterate what you've watched here, I have taken educated guesses here at the -60 kPa and above sites, by above, again it's inverse, I mean lower load, of course lower throttle position. |
| 45:21 | Once we go out to 4000 and 4500 I was actually able to drop into those cells there and get a bit of a look at them. |
| 45:27 | I couldn't stay in there in steady state but it gave me the confidence to know that those -60 kPa cells were correct but what you would have seen me doing while I was tuning those cells is -50 which I could get to, I would simply highlight the cells above that as well so when I was changing the -50, I was also changing the -60 and above cells. |
| 45:47 | Again working on the basis that if we're too rich or too lean at -50, chances are the other cells that we've kind of guessed at, probably are going to follow suit. |
| 45:55 | So let's get into making these changes and just to quieten things down a little bit, we can actually key everything off now and go back online. |
| 46:05 | We do want to obviously send these changes to the ECU. |
| 46:10 | So what I'm going to do here is just for a start, I'm just going to highlight that 4500 RPM column, hold down the control key and we're just going to copy that out to the right. |
| 46:17 | So we know that 4500, we should be pretty close. |
| 46:20 | 5000 RPM and above we don't really have a clue. |
| 46:24 | So what I'm going to do is just add a little bit of shape to this table so that hopefully as we get into these higher load areas, we're at least in the ballpark so we'll highlight 6000 and 6500, enter a value of 1.05, so we're adding 5% there. |
| 46:41 | Then I'll now highlight 5500 RPM through to 7000, exactly the same, 1.05 and then we'll do the same, 5000 RPM out to 7500, multiplied by 1.05. |
| 46:54 | So that will give us a little bit of shape, it's unlikely that we're going to be right but at least it's going to be closer. |
| 47:01 | And of course our first ramp run isn't going to be all the way to 8000 RPM anyway, we're going to be creeping up on this and we can make changes as we see fit. |
| 47:08 | Just to get a sense of what that table is looking like, let's have a look at it graphically. |
| 47:12 | And we can sort of see what we're actually dealing with here. |
| 47:16 | I can move it around. |
| 47:18 | So it's possibly a little bit peaky in that area at the moment but you know it's got what would be somewhat typical shape. |
| 47:26 | Obviously in this low load, low RPM area, or sorry low RPM area full stop, we haven't really done anything there so let's head back to the table view and see what we can do there. |
| 47:37 | So we know that we have addressed our 1500 RPM column and at the same time we know that we were idling somewhere around about here at maybe 38% so what I'm going to do here is highlight that 1500 RPM column, control and left arrow and I'm going to basically highlight that entire area. |
| 47:55 | Then what I'm going to do is highlight the area that we were idling in so 0-900 RPM and what I'll do is I'll just bring us back down to the point where we were so -60 we were around about 38. |
| 48:08 | If we want to here as well what we can do is just highlight that 900 RPM column, we'll use the shift key this time, so we don't want to copy these values across, shift key and the right arrow key, we're just going to highlight here, 900 through to 1500 RPM, you'll remember we haven't currently tuned that 1000 RPM column. |
| 48:27 | Little bit too low for me to want to do that using steady state conditions but what we can do here is use the shift and H key, horizontal interpolate and that will fill in the gaps there for us. |
| 48:37 | So let's just have a look at that graphically now and yeah now we've got something that, I mean I wouldn't say it's absolutely perfect but we're at least looking like a fuel table. |
| 48:49 | Let's go back to our table view. |
| 48:52 | So at this stage, we've got our steady state fuelling dialled in pretty nicely. |
| 48:57 | What we're going to do now is move onto the next step of our process and repeat that process essentially for our ignition timing. |
