Practical Reflash Tuning: Step 5: Optimising the Tune
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Step 5: Optimising the Tune
1.06.57
| 00:00 | - Because this vehicle is relatively stock, we don't have a need to work on the virtual VE system at this time. |
| 00:08 | So we're going to skip where that would normally occur on a more heavily modified system which can't do without it, and we're going to move onto other items. |
| 00:17 | I'm pretty happy with our air/fuel being on target in open loop now. |
| 00:22 | So here we're right there. |
| 00:27 | Little bit rich up top but for now I'm thinking in order to keep our catalyst cool, in order to keep this engine nice and reliable, we're already seeing a great gain and we haven't even touched ignition timing yet. |
| 00:41 | I'm not going to get any greedier with the fuel, I'm going to leave it as is and let's move onto timing. |
| 00:48 | Now in terms of tuning ignition timing on this vehicle for full throttle and heavy load operation, you have a few options. |
| 00:56 | One of those options are the main spark tables so let's go back to VCM Editor and take a look at those. |
| 01:04 | In the spark advance section we have the high octane table and unless your vehicle has experienced significant persistent knock, I really don't expect you to get into the low octane table a great deal. |
| 01:19 | However be mindful that the ECU will blend between the two and if significant knock occurs or a small amount occurs but sufficient enough and in a persistent nature, the vehicle will start to trend from the values in the high octane table towards the values in the low octane table. |
| 01:40 | For now, let's start with the high octane table. |
| 01:43 | What we can do is we can add timing here in the higher load areas that we're experiencing during a full throttle pull. |
| 01:54 | What's another way to do this? On this vehicle under the base correction section, under gas which is the fuel we're running since this is not a flex fuel application, we have a power enrichment cat over temperature spark advance correction table. |
| 02:14 | Now what does this do? What we see here is when we have no enrichment, we're essentially causing no change at all. |
| 02:26 | When the EQ ratio goes slightly over one, we have a mild amount of enrichment, still no change. |
| 02:34 | However, when significant enrichment occurs at a value of 1.15 or somewhere between 1.1 and 1.15, we start to bring in some additional timing advance. |
| 02:48 | So as we discussed earlier, the power enrichment system does kick in at a relatively consistent point but there's a bit of a delay and there's a bit of a transitional period where the air/fuel command blends from a stoichiometric one down to our power enrichment value. |
| 03:09 | During that transition, you don't necessarily want to apply all of your timing advance until the engine has received significant enrichment for temperature and detonation control. |
| 03:20 | So based on that, you start to see values above zero in this range and then if you look down here, with a great deal of enrichment, the factory calibration indicates that you can get even more timing advance in the motor without detonation most likely as they've made these decisions. |
| 03:44 | Based on this and based on my desire to only add the additional timing once we have enrichment in place, I'm going to go ahead and add some timing here rather than adding it in the main spark table. |
| 04:01 | I don't intend to enrich the vehicle beyond 1.2 but what I'm going to do is take this chunk here which is completely consistent between 1.15 and 1.25 and I'm going to add a degree of timing to that whole range. |
| 04:25 | Now in this particular case, I'm also going to assume that if there was slightly more enrichment we could certainly handle that same amount of timing advance so I'm going to make this area match and then here going to bring this up as well. |
| 04:50 | And while this is a relatively small change, it's always best to start small, that's your safe bet, if you make lots of changes at once, or you make big changes all at once, that's when you can get yourself maybe not into trouble but into unintended consequences let's say. |
| 05:09 | Any time we're looking to add timing, that's a great opportunity to do so with caution and care. |
| 05:17 | So we've added 1° of timing and I'm going to save this but I'm going to save it as BoostLim for boost limit change and PE timing increase. |
| 05:38 | I'll call it PE+T to indicate that I've added timing, not subtracted it. |
| 05:44 | We'll save that and now we're ready to flash the vehicle and see if that increases power. |
| 05:51 | Alright we've added some timing, we have not changed fuel, so what's the most important thing to keep an eye on during this run, knock. |
| 06:00 | So that's what I'm going to do, I'm going to really focus in on that and don't really expect air/fuel to change, other than typical run to run variance but that's been nice and safe so we're going to focus on knock during this run. |
| 06:15 | Again we're going to see that typical normal baseline knock response that we always do, we can always watch over here on the left side, the individual cylinder numbers and then on the top end of the run we can go back to looking at our typical knock retard and total knock retard to see what's going on. |
| 06:33 | Alright we're still in fourth, temperatures look good, coolant is up to temp, manifold air temperature is reasonable, let's see what we get. |
| 06:57 | Alright so looks like we picked up another 10 horsepower. |
| 07:02 | The owner is likely not going to be upset with that so let's see if we've done it without creating any knock. |
| 07:09 | So as we look at the start of the pull, we do have slight increase here. |
| 07:20 | Now let's see...yeah so no cylinder knock response. |
| 07:32 | Now I did get in the throttle really aggressively and all at once that time. |
| 07:37 | Sometimes when you ramp it up that quickly on the low end, you get into systems in place that are designed to mitigate LSPI or low speed pre ignition which is a common phenomenon on DI engines if you aren't careful to avoid it. |
| 07:51 | It typically occurs right around 1500 to 2300 RPM, mostly really close to 2000 and that's where this big change has been made here. |
| 08:03 | Now as soon as we get past that point, it looks like we go right back to what we've been seeing before and if that doesn't happen again when I roll into the throttle a little more gradually, I'm going to likely chalk that up to that type of system. |
| 08:24 | Now on the top end, looks like that typical response has gone by 5200, 5300 RPM, no knock detected on the top end, the dyno graph still looks perfectly smooth, I would say that we're good to go on the changes made on the top end. |
| 08:47 | What I do see is on the low end I'm not seeing a power increase up until about 3700, 3800 RPM and it looks like that brings us up to here so in this particular instance, I believe we've actually had significant spark reduction, yep you can see it right there. |
| 09:16 | So based on that, I'm going to do another run just to see if that repeats or not before we go ahead and make any other changes. |
| 09:24 | If it does it again without me really mashing the throttle really violently all at once, maybe it's going to be OK if it doesn't do it again but if it happens again without me really mashing the throttle, then we're likely going to take that timing we've added in that area and pull it right back out. |
| 09:45 | Alright and at this point I'm going to remove the middle run which is Modified2, that way when we do our next run, we're comparing directly to another run at the same calibration. |
| 10:00 | Because we haven't had a bunch of cooldown time while we're making changes, it's possible we'll get to see what a little bit of heat soak does. |
| 10:08 | Let's start a new log and see where our manifold air temperature is. |
| 10:12 | OK so manifold air temperature starting out about 10°F higher than the last pull was and because of that we may actually see a slight reduction in power output but let's just give it a shot and see what happens. |
| 10:28 | Alright and this time again I'm going to roll into it a little bit rather than just really aggressively slamming my foot down and see what that does. |
| 10:39 | As long as the transmission lets me decide what gear I want to be in. |
| 10:43 | Alright fourth gear. |
| 10:54 | Alright so we can see right away, now we're back to that profile we had earlier when I wasn't just absolutely matting the throttle all at once. |
| 11:04 | We've got that initial 1.9 and 3.9 on the knock response and ramping up to 2.5 and 4.9. |
| 11:13 | What we do have that's different is right here we have an actual knock retard event so cylinder 3 picked up some knock and pulled some timing out. |
| 11:25 | Where did this occur, at 4500 RPM and looks like our air/fuel was reasonable so chances are we've found a spot where we really didn't need that extra degree of timing. |
| 11:46 | Let's see what else we see. |
| 11:48 | Ah OK so if we look at the low end of this run compared to the other, we actually show more torque because we didn't get that response to me matting the throttle so aggressively so odds are the user would never do that on the road, it would absolutely blow the tyres off this thing, nobody's really going to be driving it like that so I'm pretty comfortable with the timing we've got in that area and I'm just going to focus on the area where we picked up a little bit of knock. |
| 12:17 | Now on the top end, it looks like we got just a couple of less horsepower and that's exactly what I expected based on the increased manifold air temperature that we started the run with. |
| 12:28 | So to be expected, totally reasonable. |
| 12:31 | At 4500 RPM where our knock event occurred, we have an equivalence ratio commanded of 0.86 lambda. |
| 12:39 | Now as I've mentioned before, we can work lambda back to EQ ratio by using an inverse function, so we do 1 divided by 0.86 which gives us 1.1627 or about 1.163. |
| 13:00 | Then if we go back to our calibration under engine, fuel, power enrichment, then go to the EQ ratio gas table, can see that at that RPM that is indeed what we're telling the computer to run. |
| 13:24 | So that's what we're attempting to do and the reason I wanted to look that up is now when I go back to my power enrichment spark advance table, you know exactly where to look right so we're somewhere between this row and this row and at 4400, I'm just going to go ahead and take that degree I added back out, going to take a little out there, just to blend it in and then let's just take a little closer look at exactly where this started. |
| 14:09 | Yeah potentially just after 4500. |
| 14:14 | So with that in mind, I've taken 1° out there, in the 4800 range, I'm going to take 0.5° out. |
| 14:24 | Now what we didn't see was an increase at 4000 RPM compared to the pull prior so as I look at the dyno graph, I'm not really seeing a gain and for that reason at 4000, I'm going to take that degree back out there too. |
| 14:48 | Next at 3600 there was a gain however it seems like it was mostly related to me not smashing the throttle so hard and not inducing what I assume to be, or presume to potentially be an LSPI mitigation system. |
| 15:09 | So I'm going to take half a degree out there as we likely don't need any more torque there anyway and I'm going to focus more on the top end where our timing did provide us with really maintenance of power despite increase manifold charge temp. |
| 15:30 | I'll open back up modified2, that way we can see where we really made a gain on our first pull, on modified3 before we got things heat soaked. |
| 15:40 | So it looks like we made a pretty significant gain from about 4800 RPM up, especially up top, it really seemed to like the additional timing so with that in mind, taken a little out at 48, at 52 there was a very significant gain so I'm going to go with another half degree there and see if we can continue to see a really nice sizeable gain from adding that timing. |
| 16:14 | In my opinion, even if you don't get into a knock event, if you stop seeing significant gains in ignition timing, you're running pump fuel and you're not in a race only application where you really need to push things to the limits. |
| 16:28 | Once you get to the point of diminishing returns, I feel like it's a great point to stop. |
| 16:32 | Always want to leave yourself some margin of safety and I think that's a fairly reasonable way to do that. |
| 16:39 | So we're going to save this as Modified4 and we're going to call this ModifiedT because we've both increased timing in some areas, decreased it in others. |
| 16:58 | Save that. |
| 17:02 | And go ahead and write the calibration. |
| 17:05 | I'm going to pull the Modified2 pull off here. |
| 17:09 | So we've gone from... |
| 17:14 | ...534 horsepower to 576, quite a gain. |
| 17:20 | I don't expect to get much more out of this, that seems like quite a lot so let's see what happens on this next run but we might actually be getting pretty close to looking things over more closely, getting ready to wrap them up in preparation for road tuning and validation. |
| 17:39 | We're in fourth gear, we're ready to start and again I'm going to roll into it rather quickly but not quite smash the pedal all at once. |
| 17:59 | Alright so on the low end we got our typical response. |
| 18:05 | Then we got a little bit extra, no that's our normal response, there we go, OK. |
| 18:14 | 2.5 and 4.9. |
| 18:16 | That trails off where it usually does, then we had a knock event. |
| 18:24 | So we had a single cylinder, just a hair on a second, then multiple cylinders started talking, by talking I mean offering knock retard and based on that it's safe to say alright, now we've tested the waters and there's really no room for additional spark advance on the top end so this started occurring at 5300, 5400 RPM so let's save this as Modified4, I'm going to make a note, knocked up top. |
| 19:09 | And when we look at our dyno graph, what we see is we had a really nice increase for a little bit and then we actually had a bit of a reduction because the knock retard resulted in a net loss of power on the top end so we're going to go ahead and make changes to make that a bit safer so that doesn't occur. |
| 19:33 | So from 5300 is where it started which is unfortunately because we had a really nice gain for a bit. |
| 19:44 | Looks like it was mostly one cylinder until we get here to 5700 when the second cylinder started retarding timing, that's where the power increase we were getting starts to go away. |
| 19:59 | So with that in mind, let's go back to our spark advance fuel related table and going to take 0.5° out here, full degree out here and that gets us a bit closer to where we were earlier. |
| 20:28 | Now in addition to that, I'm going to take a look at our power enrichment and see now that we've got the timing relatively dialled, maybe we'll be able to go with a slightly more conservative power enrichment figure and maybe get a little more out of the car with a different combination of spark timing and EQ ratio target in the power enrichment function so let's go back to fuel. |
| 21:00 | Power enrich. |
| 21:02 | EQ ratio, so one thing of note here, we started knocking here and at this point, the factory calibration hasn't really brought this heavy enrichment in place yet. |
| 21:14 | So I think what I'm going to try for this next test is I'm going to take this, I'm going to bring it in here then I'm going to use this function to horizontal interpolate, make those cells all the same and then I'm going to take this value here, drag it down to this one, blend those together. |
| 21:41 | So what have I done here? I've essentially ramped in a little more enrichment a bit sooner and ramped it up as the RPM increases. |
| 21:49 | So this is going to provide some additional temperature control and my hope is this way by the time we reach a higher RPM, less heat will have built in the combustion chamber, in the exhaust system, in the catalyst, and this will all reduce the likelihood that a knock event will occur. |
| 22:08 | Now I'm not necessarily going to use this to then go back and try to throw timing back in the motor, I'm merely going to use this in this street application to make this engine a bit safer and provide a bit of additional margin of safety. |
| 22:22 | So let's save these changes, last pull was Modified4. |
| 22:30 | So we're going to call this Modified5. |
| 22:34 | And this is -T and PERicher. |
| 22:47 | Shut the car down, get it ready to flash. |
| 22:53 | So in this instance, I've kind of gradually ramped in the power enrichment. |
| 22:57 | One thing that I try to avoid doing is just slamming all of it in at a super low RPM. |
| 23:04 | While there might be an application for that in a race only situation, in a street application, we want to be very careful of any additional enrichment we provide and make sure it's really just there to provide some extra reliability and temperature control and really want to avoid just throwing a bunch of extra fuel in the car, reducing fuel economy, reducing efficiency unecessarily. |
| 23:29 | While I'm waiting for that I'm going to go ahead and remove Modified4 since that one knocked a bit and I'm not really considering that a point of reference for future pulls, simply because this isn't a situation where we need to be pushing the car, I'm not going to reference against that area where we had a gain where really it was a bit on the edge and I just don't need to push it like that again so we're going to reference the pull prior which didn't have any knock at all and treat that as what we're shooting for, that or better. |
| 24:03 | And realistically, if this doesn't work out, we can always go back to that one, that's why I name the dyno graphs and the engine calibration files as I do. |
| 24:11 | If I really just find there wasn't any more left safely, all I have to do is load up Modified4 and off we go. |
| 24:19 | If we've been making some changes a little bit more quickly now and I just want to see where my manifold air temperature is. |
| 24:25 | Alright so we're up the 150s now and that's a significant increase. |
| 24:30 | At this point what I'm going to do, just for consistency and being able to really determine what types of gains or losses, improvements or detriments we're making, I'm going to let the car cool down a little bit so I'm going to give it a little bit of a rev, see if moving some airflow through the system drops things down a bit. |
| 24:52 | Get some fluid moving, get some air moving. |
| 24:56 | Yeah it's coming down. |
| 24:58 | If bringing the RPMs up, moving some airflow, moving some fluid through the water to air intercooler system hadn't brought the temps down like that, what I would have done is shut the car down, let it sit on the fans and wait but because things have come down to pretty reasonable numbers, which are actually pretty close to some of our early runs, I think now we're in a pretty good position to try and get a representative pull out of the car. |
| 25:23 | Alright fourth gear, let's do it. |
| 25:47 | Alright so on the low end, we had our typical behaviour. |
| 25:53 | Then it looks like we had a single cylinder pick up a knock event followed by a second one at about 5300. |
| 26:08 | And then a third so in this situation, you have two choices. |
| 26:15 | You can treat this as concerning, you can walk your way back, or you can give the car a little bit of time to cool down and in a situation like this, it is possible that while those air temperatures looked reasonable like earlier today, the reality is a lot of items in the engine bay really are heat soaked and give it another shot after it cools down bit and see if we can't run this tune without that knock occurring. |
| 26:44 | I have a hunch that might be the case because I know in this area we've now walked things back to where we were earlier today able to run that much timing so I'm going to give the car a bit of time to cool down since we've been doing some successive pulls and then we'll give it another shot on this calibration with no other changes and see where we're at. |
| 27:05 | Let's just save this file. |
| 27:10 | Modified5, knocked up top. |
| 27:17 | I'm going to call this heat soak maybe. |
| 27:20 | Alright so I've given the vehicle a chance to cool down a bit. |
| 27:25 | Just going to get it back up to speed, we'll do another dyno pull and see if we get the same knock we got before or if that was really just a heat soak situation. |
| 28:05 | Alright so looks like we have significant power gains over the Modified3 run. |
| 28:16 | We have our traditional knock pattern early on followed by nothing up to and at this point it's pretty safe to say that what we were experiencing before was heat soak. |
| 28:30 | Again we can see some very vital statistics like the intake air temperature, manifold air temperature, engine coolant temperature. |
| 28:39 | What we can't see is the latent heat in the engine bay, the supercharger lid, all of these items which get heat soaked during repeated dyno pulls so it's important at that point to take a step back, give the car time to get back into a condition you were operating it under previously and then see what you can do with it. |
| 29:02 | It's also a good reminder on the flipside that sometimes on a street a car could get heat soaked and we do want to leave some margin of safety for that as well. |
| 29:10 | What we did determine is that at this point, we've now gone back to timing values that worked before or slightly higher and were able to do a pull without any knock. |
| 29:22 | Now because that area at 5300 is so sensitive, I'm going to show you another option you have just to give you another way to go at this. |
| 29:32 | And again I've mentioned, I've been using the power enrichment based spark timing advance. |
| 29:37 | But we can get down a little more nitty gritty by using the high octane spark timing table and make some adjustment right around that RPM and amount of load that the engine is experiencing at the point where it's been a bit touchy. |
| 29:53 | So let's got to 5300 RPM and we have cylinder air of 1.4 at this point so let's remember that. |
| 30:09 | And go back to engine, spark, base high octane and we'll go down to this area which is right between 1.36, 1.44 over to 5200 which is the closest break point and it looks like here we have a good bit more timing, a full degree than the prior RPM break point, followed by a small increment right after it. |
| 30:49 | And what I'm going to do is just to demonstrate how this might work is I'm going to take this area here, I'm going to take 1° out of it by clicking minus twice and as you can see I've taken the timing out of not just 5200 RPM but 5200 to I'm going to take half a degree out here. |
| 31:18 | And half degree out here, just to blend that in a little bit. |
| 31:25 | And then if we go back into our table here, what I'm going to do is I'm going to add that degree I just took out back in here. |
| 31:48 | So from 5600 RPM up, and actually since we're revving slightly past 6400, I'm going to make a change here too. |
| 32:02 | I'm going to go with 3° there, just so when it interpolates between these cells, we don't lose all that timing advance and have power just totally take a dive on the top end. |
| 32:13 | Make that change there, so now we've added a degree here, we've taken a degree out there. |
| 32:19 | What's that going to do? Net, no change, however the way it comes in is a little bit different and the reason I like this is if we're in a situation where we're at a higher RPM and we're maybe on and off on and off the throttle, perhaps in a road course situation, we might not have full enrichment immediately and again this way we make sure we wait until we have solid enrichment before we apply this timing, especially in the sensitive area. |
| 32:49 | In this area we're also moving a great deal of airflow, exhaust temps have the danger or risk of getting really hot, getting the cats really hot so again it's important we don't want to go for the more aggressive tuning, in terms of the more aggressive spark advance until we have that enrichment in place. |
| 33:07 | Now I've blended down a little bit down to 48 and back here that would put us back here. |
| 33:21 | If I decide I want to bump that back in we can do it by putting the half degree back in here. |
| 33:31 | Alright so just kind of smoothing those transitions out and of course I didn't add any at 5200 because that area seems a little touchy. |
| 33:40 | If you want to play it slightly safer, we'll go ahead, take half a degree out here at 5600 and I think reasonably that's probably a pretty good approach for this setup. |
| 33:56 | Other than that, the low end's looking good, I'm going to save this. |
| 34:06 | Now we're up to PEAndMainTChanges, this is Modified6. |
| 34:23 | And I'm just going to double check our air/fuel again. |
| 34:29 | Yeah I mean we're staying pretty consistent, wideband's looking good on the top end. |
| 34:37 | OK so as I look at this dyno graph, power has slightly rolled over right at the end of the pull but I think that's because of that huge trough we had in this table here. |
| 34:52 | Also there's a huge drop between 6400 and 6800 here so what I'm going to do instead is in this area, which we're encountering, going to dump these values in, then I'm going to minus twice, take 1° out. |
| 35:18 | So we're still running a little less timing than at 6400 but we're not just totally cutting it off at the knees here. |
| 35:27 | Another thing I'm going to do is I don't like having increased spark advance with increased load and this 22.5 is now higher than this 22 so I'm just going to drop that down half a degree there. |
| 35:43 | Alright and then we'll look and see how this blends in. |
| 35:46 | I have no reason to touch these values up here, we're definitely not going to rev this thing that high. |
| 35:51 | What I am going to do at this point is I'm going to give us another 100 RPM to play with and see what happens. |
| 35:57 | So save this again before we forget. |
| 36:05 | And now I'm going to go back to our cutoff values, just going to go up 100 RPM. |
| 36:14 | So put 100 in here, add that in, really don't need it in reverse, these two question mark ones, sure we'll go for it, it's only 100 RPM. |
| 36:34 | And let's say, if the oil's really that cold, I don't need it up that high but because it's modelled, just don't have a massive amount of faith in that model or potentially right after a reset, the model value might reset something unreasonable so I'm just going to go ahead and mirror that block of values and increase all of them by 100 RPM. |
| 37:04 | Alright other than that, that limit's out of our way. |
| 37:11 | Not worried about these. |
| 37:14 | Yep so that covers our RPM limit so I'm going to save this again. |
| 37:22 | We've also now changed rev limits. |
| 37:26 | And at this point I think we've seen, or at least we have good reason to believe that heat soak is a significant factor on this platform. |
| 37:36 | Any time you're dealing with a supercharger, really any forced induction application, there's just a great deal of heat in the engine bay and with the fan setup we have right here, I think it's prudent that we give the car a bit of time here before we run it so I'm just going to give it a couple of minutes and then we'll go ahead and run it again. |
| 37:58 | Modified6 is now our new reference point. |
| 38:04 | And you may recall that we disabled the SD or dynamic airflow system earlier in the day. |
| 38:12 | That's why we were really focused on the MAF tuning. |
| 38:16 | What we'll do is after we get the rest of the tuning optimised, then we're going to throw that SD system back into play, run the car again, just to make sure it doesn't make any significant difference but because this is a factory engine, we haven't really significantly altered the VE of the motor, I don't expect that to be a problem. |
| 38:37 | One thing we can check in the meantime, just to confirm my suspicion is at an RPM where that system would potentially come into play, let's say here prior to the pull, 1600 RPM, let's take a look at the airflow that's being calculated by the mass airflow system, 2.42 pounds per minute and the dynamic airflow system, 2.434 pounds per minute. |
| 39:06 | Now that's really really close so what that tells me is not only are these very close to each other and I really shouldn't have a concern about swapping between the two in that dynamic fashion, it also gives me a pretty good feel that in addition to our fuel trim confirmation, this is just kind of another confirmation that we've done a nice job of our MAF scaling because we're accurately representing airflow and we can see that based on it matching up with a very complex and very well defined factory virtual VE system. |
| 39:41 | So in preparation for the next pull, I'm going to go ahead and set the dyno up to go 100 more RPM just so we see a little bit more of what's going on right at the end of the run. |
| 39:56 | I don't know if this customer's going to really use that extra 100 RPM but in my opinion if it avoids him hitting the rev limiter, great, if it gives him the opportunity to go a little bit further on a pull, get a little more performance out of the car, that's great too. |
| 40:13 | 100 RPM isn't going to make or break it so we've given him a little bit more, he can use it, he can not, either way, I'm pretty comfortable with that small change. |
| 40:23 | What I don't suggest doing is a really large increase in the rev limit unless you're absolutely certain that on that vehicle platform that's going to be OK. |
| 40:33 | Not only in terms of oiling, valve train, raw bearings, but also catalyst, so the higher you go in the rev range, the more accumulative heat you're dealing with, the more cylinder pressure you're potentially dealing with but realistically in the absence of cylinder pressure, you're still dealing with a lot of rapidly occurring cylinder events, they're each putting out a significant amount of heat and that heat continues to build in the catalyst, the longer the pull continues. |
| 41:23 | Alright looking good on the low end. |
| 41:26 | On the top end, looking like a little bit of knock so we'll take a little timing out there. |
| 41:34 | Let's see what the shape of the curve looked like. |
| 41:43 | Yeah looks like that knock on the top end actually reduced power a little bit so I'm going to go ahead and pull some timing out of that area. |
| 41:54 | Now we're getting really close to having something I feel is complete in terms of dyno tuning and what we can reasonably get out of this with a reasonable level of safety so what I'm going to do is I'm going to take a little timing out of that area and then I'm going to pull a little bit out of all high load areas just so I know I've built a certain amount of margin of error into the tune itself. |
| 42:19 | So even down low here, we're seeing cylinder air over 1.2 so what I'm going to do is take care of this area here from 6100, 6400 or so and then in addition to that I'm going to take a little bit of timing out of some other areas. |
| 42:46 | Back on our spark advance, high octane. |
| 42:54 | Looks like this has increased timing as compared to 6000 RPM which potentially we don't need so I'm going to take a degree out there. |
| 43:09 | Then what I'm going to do is from 1.12 up, just to start a little sooner than 1.2, I'm going to take half a degree out. |
| 43:22 | So we're so close to being almost done, I'm ready to accept the fact that we've pretty much found the limit of where we're going to get and start dialling it back a little bit, just to wrap it up for the customer and give them a margin of safety that's known and that I'm aware of. |
| 43:38 | So I'm going to do that, then I'm going to save this as Modified8 just in case I've skipped a number. |
| 43:56 | Safer timing. |
| 44:03 | Dynamic airflow on so what I'll do there is go to airflow dynamic. |
| 44:14 | Now I remember that it used to come on at 4000 but just to make sure I actually revert the values to stock, I've opened up the stock file for comparison. |
| 44:26 | I'm going to show differences and I'm going to zero them out. |
| 44:33 | Now we have stock values there, I'll save again, so now what we're going to do, it's really putting all together what we've done today. |
| 44:43 | So we finished the MAF VE tuning earlier. |
| 44:46 | I've just left MAF as the primary airflow mechanism for these pulls, just to really keep an eye on things, make sure that's all dialled in well. |
| 44:55 | Now I want to put the dynamic airflow system back in place though just so we can see how it all comes together and how it's going to be on the road for the customer. |
| 45:05 | So I've got that back on, I've made a timing change where we had some knock. |
| 45:10 | So that should get us back to a no knock situation then I've pulled a half degree in the high load areas out everywhere and that should build in half degree extra margin of safety from where knock has occurred. |
| 45:25 | In the end, we may end up deciding to take a little more out, just because this customer isn't looking to really push the limits but at least now we know where the limit is and we've applied a half degree safety margin. |
| 45:37 | While a half degree doesn't sound like a tonne, on a DI engine, with higher compression, and this one, also added combustion pressure from a supercharger, half degree's actually a significant amount and we know that this next run should be nice and safe and what we'll probably do is if the first run looks good, I'll give it a minute, I'll do a second one as a backup and then decide where we're going to go from there. |
| 46:03 | So I'm going to use Modified6 as my reference for this pull. |
| 46:09 | Looks like that was probably our best run, if not, very close to it. |
| 46:16 | And that way we'll see where we gain or lose in comparison. |
| 46:22 | I expect to have slightly less power pretty much everywhere because of that half degree we took out for added safety. |
| 46:29 | But up top I'm curious to see if these little wiggles we have in this area smooth out. |
| 46:36 | Since we've reenabled dynamic cylinder air, it's a good idea to take a look at fuel trims again, just make sure we don't see anything that looks amiss or anything that's surprising at this point. |
| 46:48 | So right now, got really tiny trims at idle, before I do the pull I'm actually going to drive the car gently for a bit, just make sure there's not surprises there either. |
| 47:21 | It's looking really good. |
| 47:35 | Yeah I'll take it. |
| 47:37 | Alright so we're up into fourth gear, let's get ready to do our pull. |
| 47:57 | So it looks like we didn't quite hit the RPM where the pull ends. |
| 48:01 | I'm just going to take that 100 RPM out to prepare for future pulls. |
| 48:07 | And in case this happens, can do a scattergraph, so it looks like happened here is we are definitely heat soaked. |
| 48:17 | It's not really showing up in the manifold air temperature but there was a clear loss of power and it occurred even here at 5300 where we didn't have any knock retard, air/fuel's on target, we're still showing a significant loss, we also got some knock that we don't really expect so it really really looks like I've let this thing get heat soaked again and I just need to really let it cool down for a bit so I'm going to go ahead and do that. |
| 48:52 | I'm also going to take this as a sign that we could probably take another half degree out of the car so I'm going to go ahead and pull a half degree out now. |
| 49:03 | It looks like on the low end, that half degree didn't really cost us much anyway so I'm going to take a bit out here where we got some knock, bit out here where we got some knock and then we'll go from there so yeah let's go ahead and save this. |
| 49:28 | Modified8, 5800, 1.4 cylinder. |
| 49:34 | This time rather than taking it out of several areas, I'm just going to focus on the area where the knock's actually occurring and anything above it. |
| 49:46 | Now where do we start encountering that much cylinder air, let's see. |
| 49:52 | Actually for most of that pull. |
| 49:57 | Yeah we're getting a little bit of extra pressure on that run. |
| 50:03 | OK so rather than taking it out everywhere, going to focus on here. |
| 50:15 | And you know what, that's a pretty big jump up to here so I'm just going to go ahead, take a little out there too. |
| 50:30 | OK now we also had some knock at Now let's go over to our PE based adder and you'll see here we already have a lower value there, it seems to be a little bit of a touchy area so what I'm going to do is I'm going to add half degree here and then I'm going to take timing out of the main timing table there. |
| 51:01 | So half degree to there, just to be safe, we've shown that we can make a good amount of power here but really don't need to push it so from here up where we have a bigger jump between this column and this one, I'm just going to take another half degree there. |
| 51:21 | So that'll have a net effect of taking a half degree out of that area that I just bumped up the PE timing. |
| 51:28 | This I'm going to bump down half a degree as well. |
| 51:37 | Just to kind of blend things in a bit so I don't have timing jumping up as much from 4400 to 4800 cause we also have a half degree increase in here too. |
| 51:48 | So we always need to think in terms of both tables combined to result in our final timing. |
| 51:54 | So we're going to call this safer timing again and since that was an improvement, just pull that run off, continue to look at our Modified 6 as our current reference run. |
| 52:08 | Alright the car's cooled down a little bit, I gave it about 10 minutes, we'll see what kind of difference that makes. |
| 52:33 | Let's see. |
| 52:45 | Alright so on the low end, looks like because I really ramped the throttle in quickly, we had a little bit of that extra timing reduction not induced by what appears to be knock, so not a concern, then we've got our usual 2.5 and 4.9, ramping out by the usual engine speed. |
| 53:11 | And then it looks like we've got just a hint of something here only on one cylinder, 0.8° timing being pulled so very little, let's take a look at the graph and then we'll make a decision on whether we want to do something about that or not. |
| 53:30 | And that occurred at about 6200 RPM, right about here. |
| 53:43 | Yeah actually looks like the curve we have now is a little but smoother for the most part up top except for that little dip right where that occurred. |
| 53:57 | Now we're making a pretty hefty gain over stock at this point so I'm going to go ahead and take a little more timing out from about here on up, just to make this extra safe for this customer who really doesn't need to be pushing it and I'd like to give this back to him with no knock at all. |
| 54:24 | Of course under certain conditions he might see some knock here and there a little bit but I'd like to give him a nice little margin of safety. |
| 54:34 | So 6200 ish RPM, 6100 ish, cylinder air 1.38. |
| 54:51 | So we can do this a couple of ways but I'm just going to take a half degree out there. |
| 55:00 | That's a little bit easier for me. |
| 55:03 | And that gives us, that makes this whole section relatively flat which realistically makes sense right, so we have a consistent amount of enrichment for the most part on the top end, so we should realistically expect to be able to get a consistent amount of additional timing advance in the motor without detonation that we can associate with that amount of enrichment. |
| 55:27 | So let's save that, going to be Modified10 and -T high RPM only. |
| 55:40 | Other than that, wideband's still looking good. |
| 55:49 | At this point I really don't expect to get anything out of leaning the car out, other than making it hot and realistically probably making it knock so I'm not going to add any more risk in terms of fuelling or timing. |
| 56:07 | We're really actually backing things off more now than trying to push for more and that's really something I like to do at the end, just that fine tuning. |
| 56:17 | Now realistically when we're done here, if I leave some margin of safety, I expect things to be OK on the street. |
| 56:24 | Depending on the dyno you're using though, the load on the road may be significantly different, you may find, if you're on a dyno that doesn't have enough load to support a vehicle of this weight and torque, that you may need to pull a little more out before you go out on the street so really all depends on the equipment you're working with and that's something you'll get a feel for over time. |
| 56:47 | Other than that, let's go back again and look at the gap between the torque that we're reporting and the peak torque value. |
| 56:58 | So we're in this section and yeah looks like we've got a nice healthy margin there. |
| 57:09 | In terms of peak manifold pressure, this run, 180 at the end, just under it for most of it so that manifold pressure maximum threshold we had bumped up from 180 to 200 is giving us plenty of room, at least under these conditions. |
| 57:30 | Other than that the car felt really good on tip in, you can tell from the datalog that it pulls a chunk of timing in that LSPI prone area but it's making so much torque that you can't really feel it, car still feels like it's really getting up and moving. |
| 57:49 | So that's all looking good. |
| 57:55 | We're still not having any drops in high pressure fuel. |
| 57:59 | If you're, again, you're pushing the car on ethanol or you've really increased airflow a lot and you might be in danger of exceeding the capacity of the factory fuel system, you really should be keeping an eye on this but I haven't really seen this budge much from the command so really doesn't appear to be a concern at this point and again I'm actually using a little less fuel than we were earlier, before we updated the MAF scaling because we've got the car back on target so that's actually helping us as we're using a little bit less of the total fuel system capacity than when we started. |
| 58:40 | Certainly doesn't mean we're using less than stock did but less than our baseline we started with today due to our mass airflow change from our aftermarket intake. |
| 58:52 | Other than that at this point, because we've got our MAF dialled in so well, there's actually no long term fuel trimming during our pull, that means what I'm getting now, I expect to consistently get, pull after pull. |
| 59:07 | There's always going to be some slight variation in air/fuel ratio from time to time but having that MAF dialled in so you don't have significant long term fuel trims that carry over into open loop operation during a pull, really helps with consistency of your air/fuel ratio. |
| 59:27 | Again back on the graph, it's looking smooth, this variation we see on the real low end of the pull, pretty much has to do with how I get onto the throttle. |
| 59:38 | I can't start the pull any sooner because the TCM decides to kick down into a lower gear so there's a little bit of inconsistency there but it's really just due to the mechanism of getting the car into the right gear. |
| 59:54 | If we had a manual, I could probably start the pull even lower and I could roll into it in a little bit different way and that might provide a result that's a little more consistent in that low end area but because we've identified why it's happening, it's not something that I'm concerned about. |
| 01:00:12 | So while we're writing this calibration, at this point, we've gone through a pretty thorough process in terms of confirming our MAF scaling we've got our air/fuel target set the way we want it in terms of power enrichment. |
| 01:00:27 | We've got our spark dialled in in terms of the high octane table and the power enrichment based spark adder. |
| 01:00:35 | And we've checked all our limits, we're not running into any, at this point I'm not really inclined to bump any of them up out of the way because they're there for a reason. |
| 01:00:45 | If I don't have a compelling reason to bump them any higher, I'm just not going to do that so any time I'm working with a street car, making as few changes as possible to get the desired result, while leaving factory safety systems in place, is just the way I like to do it. |
| 01:01:02 | They've spent a great deal of effort dialling these cars in, I would say compared to older generations, these calibrations are really high quality and in terms of making improvements, as you've seen, we haven't touched a ton of tables but on the dyno we're seeing a really healthy gain and that's a wonderful thing, so we'll stick with that method. |
| 01:01:25 | Car's flashed, I'm going to let it sit off, we know this thing gets heat soaked, we know it's going to happen, if I try to do a pull real quick after I've been sitting at idle heat soaking, really no need to put the car through that, just going to let it cool down before we run it. |
| 01:01:42 | And at this point, I'm no longer hunting for that power we made in Modified6, at Modified9 we are making, let's see about 576 horsepower vs a baseline pull of 534. |
| 01:02:07 | That's quite a gain, really happy with that, torque's up about 19, almost 20 foot pounds. |
| 01:02:15 | And we're seeing gains across the whole RPM range, can't really ask for more than that. |
| 01:02:23 | So at this point, we're just kind of confirming our work, make sure everything's good, then we'll prepare for our road test. |
| 01:02:52 | So we've completed our pull, I didn't let the car cool for that long and we got a touch of knock on a single cylinder. |
| 01:03:00 | But the other thing I noticed was this white line which is our wideband trace, tapered down very very gradually and it almost looks like power enrichment came in really slowly there so what I'm going to do is, let's go back to our power enrichment settings and we're going to touch on the ramp in setting. |
| 01:03:21 | So I don't adjust this unless I have to but it looks like we have a compelling reason to now, I think some additional enrichment early on would help mitigate some of this knock so let's go ahead and update the ramp in gain from 1 to 1.3. |
| 01:03:40 | So that's going to help bring in some additional enrichment a little bit quicker once power enrichment becomes active. |
| 01:03:47 | And let's make that change totally by itself. |
| 01:04:17 | Alright so we can see that our enrichment came in a bit sooner, the shape of this white trace changed a little bit, rather than being super drawn out, now it arcs down a bit more aggressively. |
| 01:04:31 | So we're still really on our target up top where full enrichment is applied and in this instance we had no knock events at all. |
| 01:04:42 | I'm pretty happy with that, I'm just going to run it again after saving this log and at that point, I think we'll be ready to wrap up the dyno portion. |
| 01:05:02 | Yeah so that's beautiful, looks like great power, even with things dialled back for a little bit of margin of safety. |
| 01:05:17 | So Modified 11 Pull 1. |
| 01:05:23 | Really happy with that, nice and smooth, that's what we're looking for. |
| 01:05:29 | Alright let me run it again quick, see what we get. |
| 01:05:46 | So now we have effectively done three runs back to back because the car decided to downshift into third that one time and we only had a hint of knock on a single cylinder in one spot, other than that really clean. |
| 01:06:01 | And that's a pretty extreme test doing three pulls back to back without tons of fans on the car, I'm very happy with that and confident that will not occur during normal operation on the road so I'm going to call that good, we're going to save this run. |
| 01:06:19 | Modified11 Pull2 Actually3 and let's take a look at the dyno graph. |
| 01:06:34 | Alright so what we see is really good power up to a certain point but then it's heat soaked up top, power falls off a bit, however we didn't have significant knock and I'm cool with that. |
| 01:06:46 | So we're going to proceed to our next phase which is letting the car cool down, getting it unstrapped and getting it out on the road for a proper road test. |
