Practical Standalone Tuning: Step 9: Full Power Tuning
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Step 9: Full Power Tuning
38.14
| 00:00 | - Now we're going to move onto probably what is the more exciting part of dyno tuning which is performing our wide open throttle ramp runs. |
| 00:08 | Now we know we've already got a good fuel and ignition table set up and our steady state tuning. |
| 00:15 | And we've got that tuned out to around about 4500 RPM. |
| 00:19 | So what we're looking at doing is filling in the area between 4500 and our engine rev meter. |
| 00:26 | And we are going to be looking at doing that in ramp runs on the dyno. |
| 00:32 | Now this kind of replicates most accurately how we are actually going to be using the engine in that area of the fuel and ignition tables. |
| 00:42 | What we want to do before we move on and actually start doing some ramp runs is we want to make a couple of changes to our VE and our ignition tables just to help make sure that the tables are as safe as possible before we begin tuning. |
| 00:59 | What we are going to do first of all is in our ignition table we're going to highlight the top two rows of the table so the 100 KPA and the 90 KPA rows and that's the areas that the engine will operate and on the wide open throttle and we're going to just reduce the timing in that area to two degrees. |
| 01:21 | By all accounts this should have our ignition timing a little bit retarded from MBT. |
| 01:27 | But again it's always a good idea to start with the timing safe and retarded and then advance the timing up. |
| 01:34 | Now let's swap across to our VE table and we're going to do a similar thing to our VE table. |
| 01:41 | What I'm going to do highlight the top two rows and this time I'm going to use a math function. |
| 01:48 | So I'm going to press the Z key and then the multiply sign and I'm going to add 5% to these top two rows. |
| 01:57 | This again aims to have our air fuel ratio or our lambda slightly richer than necessary before what we start tuning. |
| 02:07 | It's always a good idea to tune from a rich and retarded area and then organize ignition timing and our fuel tuning to get back towards our target. |
| 02:20 | We are going to approach this ramp run tuning in exactly the same way we approached our steady state tuning. |
| 02:26 | As long as we are not suffering from any knock or detenation we are going to focus first on our fuel tuning. |
| 02:34 | Let's have a quick look at the functionality we've got on our mainline dyno. |
| 02:39 | And if I press the F2 key, this will take us through to our ramp run screen. |
| 02:45 | Now we've got a few ways we can go about performing our ramp runs. |
| 02:50 | We can set up the ramp runs by clicking the set up tab. |
| 02:54 | And you can see at the moment I'm aiming to run the engine from about 2000 RPM through to about 6300 RPM. |
| 03:03 | And we are using our ramp rate of about 400 RPM per second. |
| 03:08 | When we are choosing our ramp rate we really want to replicate as closely as possible the actual rate at which the engine will accelerate in perhaps fourth gear out on the road or race track. |
| 03:20 | This puts a realistic amount of load on the engine and means that the results we're seeing on the dyno should accurately replicate a real world situation. |
| 03:29 | So when we begin tuning remember we know that we are tuned relatively well out to about 4500 RPM. |
| 03:38 | Once we move past that 4500 RPM zone we're starting to move into that area of the VE and ignition tables that we haven't tuned and we've just taken a guess based on the shape of the existing tuned areas of the curve. |
| 03:53 | So what we can choose to do is either move slightly into those untuned areas during a ramp run and then back off. |
| 04:01 | Or for complete confidence we could simply drop our finished point of our ramp run so that we're already moving in this case 5000 RPM. |
| 04:12 | We're only moving about 500 RPM into the untuned area. |
| 04:16 | It's a great way when you are first getting started that means there's absolutely no way you can make a mistake. |
| 04:23 | So let's have a look at that first. |
| 04:25 | And then I'll show you a more advanced technique as you are a little bit more comfortable with how the tuning progresses. |
| 04:33 | So what we are going to do is start our ramp run. |
| 04:37 | And we are going to look at how we can use the logging on on our AM infinity ECU as well as the dyno to help us optimize our tune. |
| 04:46 | So let's get our engine into fourth gear now. |
| 04:50 | And we'll do our first run. |
| 04:57 | And it's always a good idea before you do your first run to make sure that engine temperature and your engine intake air temperature is stabilize. |
| 05:05 | We want realistic values. |
| 05:07 | You don't want the engine heavily heat soaked before you do a run. |
| 05:30 | Okay there's got our first run complete there. |
| 05:33 | And you can see that we are registering something around 140 Kilowatts at the wheels. |
| 05:39 | The red line here represents our Lambda trace. |
| 05:43 | So in this particular instance this is the Lambda being transferred through from the infinity ECU via CAN into the dyno. |
| 05:53 | And as you can see here it's got an incredibly slow update rate. |
| 05:57 | So when we normally would be able to use the data straight from our Lambda sensor on the dyno. |
| 06:04 | In this case it's not going to be that useful because the update rate is too slow. |
| 06:09 | So instead what we are going to do is rely on the logging in the infinity ECU. |
| 06:15 | So let's stop our logging now. |
| 06:17 | If you wish you can save the logging or in this case we are going to be doing quite a lot of manipulation and changes to our tune so we're not going to be really that worried about saving our log file. |
| 06:33 | So let's just zoom in so we can get a better perspective on exactly what we had during that ramp run. |
| 06:39 | So you can see on our log file we have our red line which is our engine RPM. |
| 06:45 | So you can see where the run actually started. |
| 06:47 | If we click on the little pointer we can actually lay the cursor on the part of the load file. |
| 06:55 | And the data that we will see here on the text grid will actually represent the data at that particular point in the log file. |
| 07:05 | So our green line here is a our lambda value. |
| 07:09 | And the white line is our target lambda. |
| 07:13 | And as you can see for most of the run we are a little bit richer than our target. |
| 07:20 | If we look right at the top of the run though. |
| 07:24 | So we ended up at 5,100 RPM at the very top and you can see in this point our green line actually matching our target really nicely. |
| 07:33 | So that's good to know. |
| 07:36 | And that's why we start by adding a little bit of additional fuel into that area so that before we move into an untuned area we know that we are going to be safely rich. |
| 07:48 | Anytime I point to position on the log file you can see that we end up with a cursor showing where abouts the infinities VE table the engine was accessing ECU at that particular point. |
| 08:06 | So what we can do is simply move through our log file and I like to choose zones. |
| 08:14 | So in this case we are right on our 2,000 RPM breakpoint. |
| 08:17 | And what I like to do is use the feedback from our data log here to help us tune our VE table a little bit more accurately. |
| 08:30 | So again here we are using our correction factor. |
| 08:32 | So we are using the measured air fuel ratio our lambda over our divided by our desired air fuel ratio to calculate a correction factor that we can apply. |
| 08:45 | So let's have a look at that now. |
| 08:47 | We will bring up the calculator function in my laptop. |
| 08:49 | Click on that. |
| 08:51 | And so let's move this out of the way. |
| 08:55 | So at this particular point at 2,000 RPM our measured Lambda at 0.83 and our desired lamda at 0.88. |
| 09:06 | So our correction factor is 0.94. |
| 09:09 | What this means is we want to take 6% fuel out of those particular cells. |
| 09:17 | Unsurprisingly that's actually pretty close to the amount we put in. |
| 09:21 | Remember we added 5% before we started. |
| 09:23 | So what we can do is now use our math function. |
| 09:28 | So remember we changed the 80 and the 100 KPA zones. |
| 09:31 | The reason I'm doing that is because you can see here that our actual manifold vacuum is 96 KPA. |
| 09:40 | So what we are very close to 100 KPA. |
| 09:43 | There is some interpolation going on and that's why I added fuel to both the 80 and the 100 KPA cells and rows and now I'm going to take fuel away. |
| 09:53 | So let's use our math function and we are going to multiply by 0.94. |
| 10:00 | It was actually 943 to be very accurate. |
| 10:04 | And that should correct that particular cell. |
| 10:07 | And now what we want to do is simply move through to the next point in our table. |
| 10:14 | And we are going to do exactly the same process. |
| 10:17 | This time I'm going to use the calculator. |
| 10:19 | I'm just going to look again and our measured lambda's .84. |
| 10:25 | Our target is .88. |
| 10:28 | So we are around about 4% to rich there. |
| 10:30 | So I'm just simply going to take 4% out of that so we will multiply it by .96 to remove 4%. |
| 10:39 | Let's continue through and our next site is at 3,000 RPM. |
| 10:44 | We'll get through to our 3,000 RPM point and you can see at this point we are around about 6% rich, 0.83 versue 0.89. |
| 10:59 | So let's multiply by 0.94 to take 6% fuel out. |
| 11:09 | So you can see that using this math function and the feed back from out data logging is a very powerful and very fast way of making these correction to our fuel table. |
| 11:21 | And we can just simply go through and correct these and this should mean that when we perform our next pull on the dyno we should already be very, very close to our target. |
| 11:37 | So we don't need to go through and do these trial and error adjustments to our VE table. |
| 11:44 | We should be very, very close after our very first adjustment which we are doing now. |
| 11:52 | So that's our 4000 RPM zone adjusted. |
| 11:54 | Let's get through to our 4500 RPM. |
| 11:56 | And we'll adjust that. |
| 12:01 | So we are around about 5% to rich there, 0.82 versus 0.87. |
| 12:06 | So we'll multiply it that zone by 0.95. |
| 12:11 | Now remember when we got up to 5,000 RPM we were actually on target. |
| 12:16 | We were really good out at 5,000 RPM. |
| 12:19 | So I'm not going to make any adjustments there. |
| 12:24 | So we are ready for our second one now. |
| 12:25 | I'm just going to press control to begin our data logger. |
| 12:28 | We can also commit those changes by pressing shift control C so they actually stores the changes we've just made into the ECU. |
| 12:38 | Now we are going to perform another run. |
| 12:41 | But first of all, what we going to do is we're going to save our run. |
| 12:46 | And we are going to do this so we can compare ah, back later on and we can even overlay our runs to see whether we're going forwards or backwards. |
| 12:57 | This becomes more important when we are making adjustments to our ignition timing. |
| 13:02 | I always just give the runs something sensible so I can relate to them. |
| 13:06 | So in this case I'm calling it tune 1. |
| 13:08 | If you wish you can add some notes about the changes you have made for that particular pull. |
| 13:15 | And we'll save that run. |
| 13:17 | Now actually before I perform out next run. |
| 13:20 | We're going to click on our set up. |
| 13:22 | Now we went out to 5,000 RPM during that run. |
| 13:25 | This time we want to go out a little bit further into our untuned area. |
| 13:29 | Now if we aren't confident with the dyno I would recommend increasing our run length in 500 RPM increments. |
| 13:37 | Of course, if you are familiar with the dyno operation and you are comfortable with everything there is no harm in having your run length all the way out as far as you'd actually like to go. |
| 13:47 | And of course we are going to be watching our lambda and listening for knock during the run anyway. |
| 13:53 | If something isn't right, if you are not comfortable with the lambda, or you are not comfortable with the engine, perhaps beginning to detonate you simply back out of the throttle, punch the clutch and you can abort the run. |
| 14:05 | So you don't need to stay in the run even if the run is out to six and half RPM for example. |
| 14:12 | Right so, let's do our second run now. |
| 14:16 | And what we are going see is this run will actually be over-layed directly over the top of our last run that we just done. |
| 14:24 | So we'll get into fourth gear again. |
| 14:27 | We'll give the engine a chance to settle down for all the attempts to stabilize. |
| 14:37 | And we'll be ready to perform our second run. |
| 14:38 | Alright let's get started. |
| 15:01 | Alright so that's our second run complete there. |
| 15:02 | And we move further into our untuned area and you can see that we've got a result on our dyno of over 145.9 kilowatts or 195.6 horsepower at the rear wheels. |
| 15:15 | Now again, you can see that the data that we've got here for a lambda it is overlaid over our last plot. |
| 15:24 | But again simply due to the very slow update rate of this particular data set from our Infinity. |
| 15:29 | This isn't strictly that useful for our tuning. |
| 15:32 | What we can see is that our green line which is our current graph. |
| 15:37 | Unsurprisingly, is overlaid directly over the top of that last run that we only did at up to 5,000 RPM. |
| 15:45 | That's exactly what we'd expect. |
| 15:46 | And you can see we've moved into this untuned area. |
| 15:49 | Okay, so let's a look at our data-log this time and see exactly what we've got to deal with. |
| 15:57 | We'll just zoon in a little bit so that we've got a little bit more detail. |
| 16:00 | And we can see that this time our lambda through out our run if we actually click on our run. |
| 16:08 | Through out our run is now very, very close to our target. |
| 16:12 | You can see at this point 0.87 versus 0.88. |
| 16:16 | We do have an area from about 3,200 RPM through to about three and half thousand RPM. |
| 16:25 | We're about 2% leaner than we would like. |
| 16:28 | Now this is one of those areas where we may now choose to add an additional column. |
| 16:34 | See, the problem is that if we look at 3,000 RPM we're exactly on our target. |
| 16:42 | And if we move through to three and half thousand RPM we're also very close to our target. |
| 16:48 | So the main area that we've actually got a problem is actually in between it at 3,250 RPM. |
| 16:55 | So let's simply right click on our table. |
| 16:58 | We'll add column and we'll add one at 3,250 RPM. |
| 17:03 | After I do add that column, I just press shift control c again to commit those changes. |
| 17:10 | All that does is it adds a column and it straight away and interpolates the numbers. |
| 17:17 | So the effect on tuning will be nothing. |
| 17:19 | The numbers will be exactly the same as if we hadn't had that column. |
| 17:24 | But now what it does allow us to do is make changes to those zones. |
| 17:28 | So now what I'm going to do is highlight the 3,250 and 3,500 RPM zones again at 80 and 100 KPA. |
| 17:37 | And remember we are about 2% lean there. |
| 17:41 | So I'm just going to add 2% by multiplying by 1.02. |
| 17:47 | The net effect of that one change you can see despite the fact that we are a little leaner at 3,250 RPM. |
| 17:54 | You can see that our target and our lambda match very, very closely. |
| 18:00 | When we are talking about tuning the lambda or air fuel ratio values as well you still have to realize that we are talking about a moving target. |
| 18:09 | We are never going to have an absolute 100% fixed lambda reading. |
| 18:13 | And we'll see a variation from run to run. |
| 18:16 | So when I'm targeting let's say 0.90 lambda I'm typically going to be happy as long as my lambda is within perhaps plus or minus 0.01 lambda of my target. |
| 18:32 | Okay, let's move forward though and we can see that as we move out to our 5,000 RPM zone here on our lambda is absolutely on target. |
| 18:43 | But remember we moved out further on that run. |
| 18:47 | I backed off just past 5,500 RPM. |
| 18:50 | And you can see now our lambda in this untuned area is starting to move a little bit richer than we would like. |
| 18:59 | We had 0.81 with a target at 0.86. |
| 19:04 | So as we move into these high RPM areas we are now starting to see our lambda drift a little rich. |
| 19:12 | So we need to correct that. |
| 19:14 | And because we copied and interpolated and extrapolated the shape of our table across into these untuned areas what I'm going to do is I'm going to correct the wide open throttle areas. |
| 19:29 | And I'm also going to correct the entire table in that area. |
| 19:33 | And again this is just an estimate based on the fact that if we are too rich at wide open throttle we are probably likely to be rich at lower manifold vacuum's as well when we close the throttle. |
| 19:47 | So in this case we are 5% too rich. |
| 19:51 | So let's multiply it by 0.95 to remove 5% fuel from these areas. |
| 19:58 | We'll press control shift C to commit those changes. |
| 20:04 | We'll start our data-logger and we're ready to perform another run. |
| 20:14 | Alright let's perform another run and we'll see the results of those changes to our VE table. |
| 20:19 | And again we are just going to allow the engine to settle so that we're always trying to start our run from similar engine coolant temperature and intake air temperature. |
| 20:30 | Alright, let's go. |
| 20:52 | Okay, so that's our run complete there. |
| 20:53 | We've got again 145 kilowatts at the wheels and again we are not really looking at our power so specifically right now. |
| 21:03 | But let's stop our data-logger and we will again just zoom in a little bit and have a better look at how those changes have affected our lambda and what further changes we need to make. |
| 21:17 | So you can see straight way our green lambda one trace is very, very close to our target. |
| 21:25 | Remember last time we had a problem at 3,250 RPM, and you can see that adding that extra column into our VE table has allowed us to accurately fix that. |
| 21:37 | We still have an area here at 3,100 RPM where we are around about 2% lean and we can address that in a minute. |
| 21:46 | However, for the most part we are very, very close to target right the way through. |
| 21:52 | Certainly we are within about 2% everywhere. |
| 21:55 | The area that we are moving quite rich and this isn't unexpected is obviously as we move further into the untuned area of our VE table. |
| 22:08 | So here at 6,000 RPM we are now around about 6% richer than our target. |
| 22:16 | And we went out to 6,250 RPM and we are around about 7% too rich there. |
| 22:26 | So what I will do is we will make some changes to try and correct those areas first and then we'll have a look at some fine tuning to the rest of the table. |
| 22:36 | So first of all I'm going to start by making changes to the 7,000 RPM and the six and half thousand RPM column where we didn't quite get out to 6,500 RPM. |
| 22:46 | At 6,250 we were 7% too rich. |
| 22:52 | So I'm going to start by removing 7% from both the 6,500 and 7,000 RPM columns. |
| 23:00 | So let's multiply those by 0.93. |
| 23:08 | If we move back to 6,000 RPM we can see that we are around 5% too rich in this column. |
| 23:17 | So let's multiply that by 0.95. |
| 23:23 | Now the point I've just highlighted, both the 6,500 and the 7,000 RPM column, what you can see is we do have a general trend to the shape of this curve. |
| 23:36 | So I've reached peak VE and we've dropped away. |
| 23:39 | You can see that generally as we move higher in the rev range we're going to see that the VE tend to drop off further. |
| 23:47 | So at the moment at that 7,000 RPM column we could probably safely guess that that will actually want to continue that downward trend. |
| 23:58 | So I'm going to do that manually just by reducing that a few percent. |
| 24:03 | Okay, so we've corrected those areas and hopefully that should get us closer to our target. |
| 24:09 | Now we're going to have a look at some areas where we might want to do a little bit of fine tuning. |
| 24:14 | So what I'm going to do is concentrate on any areas where I've got about a 2% error. |
| 24:20 | So for example at 5,100 and 5,300 RPM we're around about 2% lean. |
| 24:30 | This again represents an area where we don't have a zone at 5,300. |
| 24:36 | And if we look at 5,000 RPM we are exactly on our target. |
| 24:41 | And then if we also go to 5,500 RPM we are almost perfectly on our target. |
| 24:49 | So to correct that probably what we should do is add a column at 5,250 RPM. |
| 24:56 | And I'm just going to press shift control c to lock in that change. |
| 25:02 | And what I'm going to do is highlight the 5,250 RPM column we just added. |
| 25:08 | And I'm going to add 2% to that column. |
| 25:13 | We are also a little bit rich here at 4,250. |
| 25:20 | This represents exactly the same problem. |
| 25:23 | Cause at 4,000 RPM you can see we are almost perfectly on target. |
| 25:28 | And at 4,500 RPM, again we are perfectly on target. |
| 25:32 | So this is why we don't need to be so worried about having very high resolution to start with. |
| 25:38 | You can see how easy it is to simply adjust our break points in out table as we see fit once we actually get started with our tuning. |
| 25:50 | So let's now make a change to the 4,250 RPM zone column that we just added and we're going to remove 2% fuel there. |
| 26:03 | So we will multiply by 0.98. |
| 26:06 | The rest of the VE curve I'm quite happy with. |
| 26:11 | We are close enough to our target. |
| 26:12 | So let's perform another wide open throttle ramp run and see if we've corrected our lambda out at the higher RPM range. |
| 26:34 | Alright we will let our engine settle, get everything up to normal temperature and let's perform our next run. |
| 26:58 | Okay so I'm happy with what I saw there during that run. |
| 27:01 | We've got 146.9 kilowatts. |
| 27:04 | If we look at our data-log here you can see that we are right on our target within 1% throughout the range. |
| 27:12 | Right on the very top end we're around about 1% rich. |
| 27:18 | And I'm not going to worry about that. |
| 27:20 | This is an iterative of process and of course we can continue going through making smaller and smaller changes. |
| 27:28 | But the key point is here the process we go through running the engine through until our untuned area gradually using our correction factor to calculate the correct VE values to have in those untuned areas and applying it to those parts of the VE table. |
| 27:47 | So that we are not doing a trial error and adjustment. |
| 27:50 | We can very quicky in just a few runs dial our VE table in completely. |
| 27:57 | So not that we've done that let's move through and we're going to look at doing the same process. |
| 28:01 | Only this time we'll be tuning our ignition timing. |
| 28:05 | Now to do this, we want to save our run now. |
| 28:09 | And we'll call this ignition base. |
| 28:16 | Now this just means this is our base ignition timing. |
| 28:20 | And this will allow us to very accurately see whether the changes we are making to our ignition timing are positive if we are moving in the right direction and if we are adding power and torque or whether we are seeing no improvement. |
| 28:37 | Alright let's start by going into our ignition table here and remember we took two degrees out of our entire table. |
| 28:47 | That's before we started doing our fuel tuning. |
| 28:50 | Let's begin for our first run now by adding that timing back in. |
| 28:55 | So this should have us back to MBT, albeit we don't know what we are going to want in those untuned areas. |
| 29:02 | So let's do a run now and see what that additional two degrees has resulted in. |
| 29:07 | Alright we'll just get back into fourth gear. |
| 29:10 | Again always being aware of our engine coolant temperature and our intake air temperature to make sure we are getting as consistent runs as possible. |
| 29:23 | Alright let's start. |
| 29:25 | Let's see what the additional two degrees has given us. |
| 29:49 | Okay, so we've got our run complete there. |
| 29:51 | This is a really good demonstration of exactly how sensitive of the engine torque is to timing when we are close to MBT and also how we can use the dyno's power feedback to show us when we are not seeing an improvement. |
| 30:09 | So in this case the purple run which we can hardly see here is almost overlaid completely with the run we've just done. |
| 30:17 | What it's shown us is the additional two degrees which his looked like in steady state what we did want we've actually seen very little improvement until we get up around about 5,000 RPM. |
| 30:30 | We're just starting to see areas at 5,000 RPM where the engine has shown an improvement from that additional timing. |
| 30:38 | So if we see a situation like that where we've got no improvements from additional timing. |
| 30:43 | What we want to do in any of those areas will simply remove that additional timing I've just put in. |
| 30:49 | So what I'm going to do there the first place we see a gain is about 4,500 RPM. |
| 30:54 | So in our ignition table here I'm just going to highlight out to 4,000 RPM and we will remove our two degrees back out. |
| 31:08 | More realistically what I would do here because we are interpolating between 100 KPA and 90 KPA during this run, I would probably keep a smooth shape and I would remove two degrees from our hundred KPA row. |
| 31:25 | And I might only remove one degree from our 90 KPA row just to give us a smoother transition as we move up in the load. |
| 31:36 | Or we can see here right out at the end of our run we have seen a slightly bigger improvement from that additional timing. |
| 31:43 | And we can see that that actually occurs right at the end of our run at about 6,200 RPM. |
| 31:48 | So we saw an improvement there and because we've seen an increase in our torque what I would generally do then is add a little bit more timing and again see if we get to continue improving the torque. |
| 32:03 | So what I'll do is from 6,000 RPM and above I'm going to add another two degrees. |
| 32:12 | It's also a good idea if we've got a trend like this in our table and we're seeing twenty-three degrees and then a jump to twenty-five degrees normally what I would also do just to smooth out the change in the ignition advance and result in a smoother engine I would normally increase the 5,500 RPM zone by one degree as well. |
| 32:39 | We always want to have the shape of our ignition table as smooth as possible. |
| 32:44 | It's going to give us an engine that is also smooth in it's response. |
| 32:50 | Okay, so let's do another run now and see what our results are. |
| 32:54 | And again, we don't want to be overlaid over the top of that last run. |
| 33:06 | Alright we are ready to go so let's see the result of that change. |
| 33:30 | Okay so we've completed our run there and you can see that we haven't really picked up any more power from the top end from our additional two degrees. |
| 33:41 | We are starting to get to a position where the ignition curve is relatively optimized for this particular engine and we are not really seeing any effect from that timing. |
| 33:55 | So remember we just added in two degrees of timing there above 6,000 RPM and at that point we actually haven't seen any improvement. |
| 34:05 | What we did see is a small spike from that additional degree at five and half thousand RPM. |
| 34:11 | So what we'll do is just follow that trend for 5,500 RPM out as long as we have no knock occurring. |
| 34:19 | And we'll leave the timing set from twenty-four degrees at 100 KPA and we have twenty-five degrees and 90 KPA. |
| 34:30 | The other thing that we can do as well is copy that particular trend that we've got in our table further down because remember we are only looking at our wide open throttle areas in the ramp run. |
| 34:47 | So we've added a degree of timing in these areas at wide open throttle. |
| 34:51 | And there's a pretty good chance that the engine also wanted that additional degree in the lower load areas. |
| 34:59 | Now this area also isn't as critical. |
| 35:03 | We're not really concerned with having optimal torque at part throttle and 6,000 RPM. |
| 35:10 | Because generally we are only going to be transitioning through that area. |
| 35:14 | So as long as we are close to MBT we have a well, we have a smooth shape to our ignition curve I'm not going to be too fussy about optimizing that curve completely. |
| 35:26 | Now, we've looked at the fueling. |
| 35:29 | We've looked at our ignition timing. |
| 35:32 | One last area we do want to have a look at is the part throttle areas of our high RPM operation. |
| 35:41 | Now remember what we've done at this stage in those untuned areas of the high RPM range we have simply extrapolated the shape of the curve and then when we've made changes to our wide open throttle area we've also made changes to the part throttle area as well, assuming that if we were too rich at wide open throttle we'll conversely be too rich at part throttle. |
| 36:08 | Last place that I will adjust the tuning is I will just have a look in steady state briefly at the air fuel ratio in these areas. |
| 36:18 | Now I'm not going to be too fussy here. |
| 36:20 | Essentially because we are only going to be passing through this area provided that the fueling is not excessively rich or lean. |
| 36:28 | I'm just going to be happy with leaving that as it is. |
| 36:32 | We don't need to be absolutely 100% accurate in that area. |
| 36:37 | So I'm going to be a little broader in the range of lambda that I'll be happy allowing. |
| 36:44 | Once we've got our VE table and our ignition table optimized and like we've just seen there may still be some engines where we may want to try adjusting our mixture and seeing if that allows the engine to accept more ignition timing. |
| 37:04 | This is going to be very important to keep in mind if you are tuning an engine that is very, very sensitive to knock. |
| 37:13 | Now sometimes targeting a richer air fuel ratio will help control the combustion charge temperature and that may allow us to add a little bit of additional ignition timing which can in turn allow us to make a little bit more power. |
| 37:30 | Now with a VE based fuel model like that all we need to do to make these changes once we have tuned our VE table is go into our lambda target table and adjust our lambda targets to suit here. |
| 37:43 | So when we adjust our lambda target the ECU will adjust the fueling to achieve our new lambda target. |
| 37:51 | So it makes it very easy. |
| 37:52 | Alright so we've completed our steady state tuning and we've now completed our wide open throttle tuning. |
| 37:58 | Let's complete the dyno-tuning segment of our tuning. |
| 38:02 | And next we are going to be looking at confirming that tune out of the road or the race track. |
