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Practical Standalone Tuning: Step 9: Full Power Tuning

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Step 9: Full Power Tuning


00:00 - We're now at a point where we can progress through and we're going to start performing some ramp runs to fill in the higher load areas of our RPM curve that we haven't been able to get to or haven't tried to get to currently, using our steady state tuning process.
00:14 Now before we go ahead and start doing this, we're going to make a couple of changes to basically make sure that our maps for both fuel and ignition are safe and conservative before we start doing our ramp runs.
00:26 So let's have a look at our tuning software here and what we're going to do is start with our fuelling.
00:33 And we're going to highlight our 100 kPa and our 95 kPa rows and we're going to go all the way through from our lowest RPM zone all the way out to 7500 and we're going to start just by adding a little bit of additional fuel, hopefully this way, we're going to if anything be a little rich when we first start doing our runs.
00:52 So in order to do this we can use our multiplication symbol and we're just going to add in this case, 3% fuel.
00:59 Now it may turn out that that's not quite enough, it may turn out that we've gone a little bit too rich but it's going to be easy to change that if we find we need to make further adjustments.
01:09 So that's our fuelling dealt with.
01:11 What we're going to do now is head across to our ignition table and we're going to make a similar magnitude change there, what we're going to do is simply highlight everything down to our 95 kPa cell and we're going to use the minus symbol and we're going to remove two degrees there so just safing up our fuel and our ignition slightly.
01:31 Now for our first run, we know that we've already tuned out to 4500 RPM so we should be reasonably confident that our fuelling and our ignition are relatively well dialled in up to 4500 RPM.
01:44 So for our very first run, let's just have a look at what we're going to actually get if we go out that far.
01:50 So let's head across to our dyno, we'll go to our setup here and what we're going to do is at the moment just adjust our end speed.
01:56 So at the moment this is rated in terms of hub RPM but we can see our RPM is shown directly below here so we're going to set our end speed down.
02:04 So for the moment we're just going to try and get out to about 4500 RPM or thereabouts.
02:12 So let's just get that dialled in.
02:14 That's going to be close enough for our purposes right now.
02:16 We can see that we're also starting our run from basically just on 2000 RPM.
02:20 So we'll click OK here, we'll get our fan up and running and let's get our first run on the board.
02:26 Now while we're doing this, we're going to be able to watch our air/fuel ratio directly on the dyno screen.
02:32 But at the same time what we're going to do is if we come across to our graphing and logging tab here in our TunerStudio software, what we're going to do is click start datalogging, we can save that datalog and this is going to log while we're performing this ramp run, makes it really easy to make specific changes to individual cells.
02:50 So let's get our first run underway here.
03:05 So we've got our first run complete there, on the dyno screen we can see we've got a fairly uninspiring 73.7 horsepower at the rear wheels.
03:11 The more important thing for our first run though is just we're makng sure that our fuelling is under control.
03:17 So we can see our red plot there showing that we're probably a little bit richer than our target of about 0.90 for the majority of that run.
03:24 Let's jump into our tuning software though so we can be a little bit more specific with this.
03:30 So on our graph views here at the top I've got our RPM and I've got in our second graph, I've got our target lambda as well as our measured lambda and these are really the most important things for us right now.
03:41 So what we could do is zoom in a little bit so we've got a better idea of exactly what's going on.
03:46 So in this instance we can see in purple our target lambda was consistent, stable flat line there at 0.91 lambda.
03:53 Remember that comes from our air/fuel ratio target table.
03:56 Our green line here is our measured lambda and we can see that that moves around a little bit.
04:02 It's actually pretty good with that 3% that we added in, you can see that we're right on our target here, 0.91 lambda.
04:08 Right out at the end of our run here, 4500 or 4800 RPM we got out to, we can see that we're going just a touch rich, we're only 1% there so I'm really not going to be too concerned with that.
04:19 What I know is that I've got safety in there, we're comfortable to run the engine out a little bit further.
04:25 Now we can see here at 3100 RPM, let's call it, we are a little bit rich here, we're 0.87 so now we're about 4% rich.
04:34 And the advantage with using the logger here is that we can see exactly where abouts we were accessing in that VE table at any particular point.
04:44 Given that we're pretty close to our target here, I'm not going to make any changes for this round, instead what I'm going to do is actually extend our RPM range.
04:52 We will start our datalogger again and what we're going to do this time, because we're pretty good there with our fuelling, we're going to save this run and we'll call this Run 1 so that we can get a little bit of an idea of where we're going in terms of overlays as we continue to set up runs.
05:10 That's going to stay live on the screen there.
05:13 I'll just cancel that for the moment though and we'll change our setup here and what we're going to do is extend our RPM range.
05:19 So we'll come out this time to, let's go a little bit further than that.
05:26 So that's going to take us out to about 5500 RPM so about 1000 RPM beyond where we had already tuned.
05:34 So we're going to be able to see what sort of effect the fuelling, or what sort of consistency we've got with our fuelling compared to our target out in that higher RPM range that we haven't reached.
05:43 Now it's important to mention here that we are going to be watching our air/fuel ratio so if we do start to see it go excessively lean or for that matter excessively rich, it's easy enough to abort our run and we can come back, make some changes and then try again.
05:56 So we'll click OK here, let's get our second run underway.
06:13 Alright with our second run complete, we can see that our air/fuel ratio still was pretty close to our target right through that run.
06:18 We've got just under 90 horsepower at the wheels right now, still nothing to write home about but we are getting further through that rev range.
06:25 Let's have a look at our logging in our TunerStudio software here.
06:30 And again we're looking at our green line here for our measured lambda.
06:34 And again we're pretty close, right out into the higher RPM range we're actually right on our target, 0.90 so that's all looking pretty good.
06:42 We can see at this point here we do have a little bit of a lean hole, we're only 2% lean there so again it's nothing that I'm going to be too worried about at this point and again we've got that same rich spot at about 3100 RPM.
06:57 Now because they're so close, at this stage again I'm not going to make any individual changes to those zones.
07:03 So what we're going to do is simply extend our rev range out because our guess to the shape of that VE curve when we've finished our steady state fuel tuning, has turned out to be a pretty good guess.
07:13 And this is one of those advantages of just adding in a little bit of shape, preempting what you're expecting the engine VE curve is going to look like and if you get that right, it's going to really speed up this process.
07:24 So we've done two runs now, our fuelling is still really good.
07:27 Let's save this particular run and what we're going to do is call that Run 2, again this will stay on our board and before we make our third run, we're going to just extend our RPM range out again and we'll go about another 1000 RPM, so let's go out to, in this case, 6350, we'll go a little bit further than that.
07:51 So we will get our third run underway.
07:55 Again we will log the results while we're doing this run.
08:15 Alright our third run there, 96 horsepower at the wheels.
08:18 What we can see again, as we extend out into that untuned area of the map, again our fuelling is looking really good.
08:24 So let's jump into our TunerStudio software and again we can see our green line here nice and consistent.
08:31 Right at the very top here, we're possibly just marginally rich but we're within 1% so realistically with a run to run variation, not something that I'm going to be too worried about.
08:43 So before we do our next run, let's start by seeing how we can address these areas here which aren't quite right.
08:50 So we've got a very slightly lean area here which is at 3700 RPM and we've also got this slightly rich area here which we've got at about 3000 RPM.
09:01 So again we can use the little trace function in the VE map to decide exactly where to make our changes.
09:07 So let's look at our first change there.
09:09 And if we just use the arrow keys we can sort of cycle through and see where abouts that rich spot starts.
09:14 So we can see from around about 2700 RPM we're just about 1%-2% rich and that continues through to around about 3500 RPM, 3300 RPM.
09:27 So the problem we've got here is we are interpolating a little bit.
09:30 If we go through all the way to 3500 RPM, you can actually see at 3500 RPM, we are right on our target.
09:38 So we do need to be careful how we make these changes.
09:41 For this first round of modifications I'm only going to make the change at 2900 RPM and we'll see how that actually works out.
09:49 So if we just scroll back a little bit before we make our change, we'll see what we've got here at 2900 and we are about 2% too rich so what we're going to do here, we'll highlight the two cells that we are interested in changing, we use the multiplier function here and what we're going to do is remove 2% fuel by typing in 0.98.
10:10 So that's our first change made there.
10:12 As we cycle through, we get to 3500 RPM, 3600 RPM, this is where we start going a little bit lean here.
10:21 So again interpolating here, initially as we go through 3500 we actually look like our fuelling's pretty good but as we move a little bit higher, it goes a little bit lean, so what I'm going to to here and you can actually see the shape of the curve here between these numbers, we've now got, at 100 kPa, sorry 2900 RPM, we've got 84.3% VE.
10:42 At 4000 RPM we've got 89%, we actually drop into a dip at 3500 so that could simply explain our situation there.
10:49 So what we're going to do for our next round of modification, is we'll just highlight the 3500 RPM column, 100 kPa, 95 kPa, the cells that we're going through and what we're going to do is multiply those by 1.02, so probably a little bit less than the magnitude of our error but we'll see what that looks like.
11:06 So again if we just scroll through, I'm really not concerned about the very marginal rich spot we've got there right up at 6500 RPM, it's close enough.
11:15 So what we're going to do, remembering we've set our rev limited at 7200, we're spanning our tables out to 7500, but I really want to limit our RPM here to about 7000.
11:26 So we can also see if we look over on our dyno graph, our power has peaked at about 6200, 6300 RPM so there's no real benefit in revving the engine that much further.
11:35 What we'll do is we'll go into our setup, we'll just save our third run there first and what we're going to do is just extend our RPM range out very slightly.
11:44 We just want to try and creep ourselves right out to that 7000 RPM point.
11:49 Probably go to 1950 for our next run.
11:53 So on this run we want to see if that's cleaned up the rich and lean spot that we've got in our mid range there and we'll see what happens to our fuelling once we get out to 7000 RPM so let's get our next run underway.
12:25 Alright we've got our latest run up on the dyno screen, we can see we're making 98.3 horsepower there.
12:30 We can see that our fuelling was pretty good, again getting some more detail on that though, let's jump into our TunerStudio software.
12:38 So first of all looking at that area we had in our mid range and it is looking better, there's still a little bit of work to do but to be honest it's so close now, it's almost not worth making any changes.
12:48 We've cleaned up that area we had at about 3500 RPM and we've got down at 3200, 3300 RPM, we're about 2% too rich there so really really close to our target.
13:05 We can choose to make some further changes if we want.
13:07 Probably if we're going to do anything there, it's still at 2900 RPM so what we'll do is we'll highlight out 2900 RPM zones, again using our multiply symbol, let's take out 2% so 0.98 and we'll see what that gives us.
13:23 If we look at the high RPM area though we do see that there is a bit of a tendancy for that to taper off rich right in the very top end.
13:33 We're still pretty good here at 6800 RPM, 6500 RPM we actually have a zone, we're basically right on our target there, 0.898, I'm going to round that to 0.90, our target's 0.90 so we're right there.
13:51 So it's really right up at 7000 RPM that we want to make a change.
13:55 And while this has been really easy going so far, we haven't had to make dramatic changes, I just will show you that when we find that we need to either add or subtract fuel in an area beyond what we've tuned in steady state, because remember we just extrapolated out and then made some changes to the entire columns beyond 4500, what we're going to do here, 7000 RPM I'm going to , instead of just highlighting the area we're running in, 100 kPa and 95 kPa, I'm going to highlight the entire column there.
14:25 So what we're going to do in this case is we're going to multiply that by 0.98, we can take 2% out.
14:32 Now we're starting to see the VE taper off so we're going to also extend that change that we've just made out to 7500 RPM.
14:38 We've taken 2% out at 7000 RPM and at 7500 RPM, I'm going to guess that we are probably going to need a little bit more fuel out of that, we'll go 0.97.
14:50 Alright so we've made those changes, let's get another run up and we'll see what we've got.
15:14 Alright another run up there, we've got 99.4 horsepower, we're dangerously close to that 100 horsepower mark.
15:20 And let's have a look back into our laptop software and we'll see what our fuelling looked like.
15:27 So looks like we're moving in the right direction now.
15:29 We've definitely done a pretty good job of getting rid of that little hole that we had down around about 3000 RPM, it's all looking pretty good now.
15:38 And we also ended up getting rid of some of that rich area we had right up at the higher rev range.
15:46 We're still a touch rich there but 0.898 versus 0.905, it's really not something that we're going to try chasing there.
15:55 Generally if I'm within about 1% of my target there, I'm going to be pretty happy.
16:00 So at this point I'm pretty comfortable with my fuelling so what we can do now is try adding in a little bit more timing and see how the engine responds.
16:07 So what we're going to do before we do that is we'll head back to our tuning dyno views graph.
16:13 We're on our ignition timing table here and what we're going to to is start by highlighting the entire area that we removed two degrees from and we'll just start by adding those two degrees back in.
16:23 We know that those two degrees were beneficial when we were tuning under steady state so we'll see if that pans out when we're doing our ramp run.
16:30 So that two degrees added back in, let's get another run underway.
16:52 Alright so our latest run there with our additional two degrees of timing, now it's really hard to see this now, it's overlaying on top of the other graph.
16:59 And the differences we were seeing are very minute but we can see we've picked up to 101.4 horsepower and we did essentially see an improvement in our torque and power everywhere there, we're only displaying power of course.
17:11 So this indicates that we've gone in the right direction, the engine liked that additional timing.
17:17 Given the small magnitude of that change, and also the small magnitude of changes we saw when we were performing our steady state tuning, I'm not really expecting to see significant gains beyond here.
17:28 However for the sake of testing, let's add another two degrees, we'll go back into our laptop software, I've got that entire area that we've just added timing to still highlighted and the idea here is if we see a gain in power through the rev range, we know that we've gone the right way, we've moved towards MBT.
17:46 So any areas in the rev range where we see an improvement, we're going to continue chasing that improvement until it plateaus.
17:52 On the other hand if I'd only seen an improvement at higher RPM, we'd only select those areas to add our timing to.
17:58 So in this case, let's increase our numbers there by another two degrees and we'll save our run there and we'll perform another run and see what our results are.
18:26 Alright so this time what we've seen there is we've actually lost a touch of power, although we're going to always seen some level of run to run variation.
18:34 The important thing really is to watch what was happening during that run.
18:37 And while we've seen a little bit of movement up and down here and there through the ramp run, essentially it overlaid directly on top of our last run so what that shows us is that the additional timing that we just added in, really wasn't a benefit.
18:50 So in this case our wide open throttle ramp run tuning on our MX5 is essentially complete and it hasn't been a lot of work to do.
18:57 That's not always going to be the way it pans out though but you can see that when you've got your steady state ignition and fuel tuning dialled in correctly, and you've extrapolated that out into the untuned areas and applied a little bit of common sense, following the trends we'd expect, it does really speed up that tuning process.
19:15 Now before we finish off here, that last change that we made, as we've seen, no real effect on the dyno so what we're going to do in the laptop software is just remove that additional two degrees and we're going to leave that as it is.
19:26 It's important to mention here, if we found that our engine did respond and added a lot of power and torque above let's say 5500 RPM, instead of just adding timing between 5500 RPM and above and 95 kPa and above, instead of this, because we've copied the 4500 RPM column here, we've copied this out to the right, what again we know is that if the engine wants more timing above 5500 RPM and 95 kPa just in these areas, chances are it's also going to want more timing in these lower areas.
20:04 So in this case when we're making those changes, we're going to make the change to the entire column.
20:09 So at this point out wide open throttle tuning is complete.
20:12 It has been very easy on our MX5, it's not always going to be that straightforward however the process, regardless of the engine and regardless of how many runs you actually need to get everything dialled in, is exactly the same as what we've just looked at.
20:26 So at this point, we've completed the dyno component of our tuning and from here what we would do is take the car out off the dyno onto the road or the racetrack and confirm that everything we're seeing here on the dyno is exactly what we're seeing out in the real world, making sure that our tune is going to be reliable and accurate.
20:44 Now if you do have any questions on this worked example, please ask those questions in the forum and I'll be happy to answer them there.

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