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Practical Reflash Tuning: Step 5-B: Steady State Tuning

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Step 5-B: Steady State Tuning

06.21

00:00 - In this part of the process we're going to have a look at how we can use the dyno and our scanner in order to help us with the part load areas of our spark tuning.
00:09 Now in a lot of instances there may not be a lot of work to do here, particularly if we've got an engine that is relatively standard.
00:16 Maybe with just some basic bolt ons such as intake and exhaust.
00:20 Then the factory spark maps are probably likely to be pretty close and we may not need to do any wholesale changes or make any wholesale changes to those areas of the map.
00:31 However we will have a look and see how we can go ahead and do that.
00:34 Let's jump into our scanner software and we'll see what we need to do.
00:38 So we are already set up on a histogram here that I've got labelled as retard.
00:43 However this is set up for a GM ECU so right now it's not a lot of use to us.
00:47 We're gonna go through the process and see how to set this up.
00:51 Let's right click and we'll go to our graph's layout.
00:53 We'll go to our retard histogram.
00:55 Now we're already logging to correct parameter in here, this is our spark retard parameter.
01:01 What we want to do however is change our load axis as well as our brake points.
01:06 So what we wanna do for a start is come down to our row axis.
01:09 At the moment you can see this is set to cylinder air mass.
01:12 And we want to change this to air load, so we'll just type that in, and we see air load come up as one of our options.
01:19 We'll double click on that and now we've got the right axis but we don't have the right break points.
01:25 We can head back to our editor and what we're going to do is copy those break points from our spark table.
01:33 So we'll do that by right clicking, we'll go down to row axis, and we'll click copy labels, we'll head back to our scanner, we're going to highlight the current values that we've got in that table, and we're going to delete all of those so that we can paste in our new values, so let's go head and do that now.
01:54 Alright so now we've got the correct load points, we're gonna do exactly the same with our RPM points.
02:00 So we'll go back to our editor, right click, and this time we're going to column axes and copy labels, we'll head back across to our scanner, highlight the existing labels there, delete those and control and paste, or right click and paste, we'll paste those in.
02:19 Now we've got our histogram set up, we'll get our engine up and running, and we'll see how we can use this to help us with the calibration of our spark tables.
02:29 Alright we've got our engine up and running on our dyno now, and what we're going to do is use the dyno to allow us to run through this histogram, we're going to hold our RPM steady and vary our load using the throttle and then we're going to gradually increase our RPM and fill in as much of this histogram as we can.
02:48 And essentially what's going to happen is that any time we have some spark retard occurring, so any time the ECU is detecting knock, we're going to end up with some values filling in this table.
03:00 So we're going to be able to use that to help us make changes to our borderline spark advance tables.
03:07 Now in this case you'll understand as well that we've already calibrated our spark tables above around about 1.0 load.
03:15 So we're only going to go up in this instance to 0.7, gonna focus our energies here between around about 1000 RPM and about 3000, 3500, this is going to cover the majority of the engine's operating range.
03:28 So let's go ahead and gather some data now.
04:02 Alright we've gathered some data there and by looking at our histogram we can see that our knock retard isn't doing a lot, there is a small amount of activity occurring between about 1500 and 2000 RPM at a load of 0.6 and then again at 2500 RPM with a load of 0.7 So we can now use that histogram to help us decide exactly where to remove timing from those tables.
04:26 Let's head back across to our editor and we know that we had some knock going on between 1500 and 2000 RPM at a load of 0.6 So you can remove timing here, remembering again whatever timing we removed from our map point zero table, we're also going to replicate that through our map point one, two, three, and four tables just to be consistent.
04:48 Likewise we've got a little bit of knock retard occurring 2500 and 0.7 And we can actually see that at both of these points we do have quite a sharp jump in our timing as well.
04:59 For example between 2000 and 2500 at 0.7 load we've jumped from 12 to 20 degrees.
05:07 So it'd probably be a good idea to smooth that out a little bit, let's take two degrees out of there, and likewise we will end up taking two degrees out at a load of 0.6 Likewise we also want to be a little bit sensible about the timing changes we're making and generally smooth these.
05:26 So we can see here we've got 33 degrees at 3000, 32 at 2500, and now 27 at 2000.
05:35 So what I'd probably do here is just interpolate these numbers, smooth them manually and we'd set that at 2500 the value, set that from 32 down to 30 degrees.
05:46 Now we can go and apply these same changes to the rest of our maps, we can flash that in and we can test again with our histogram to see if that's removed our knock.
05:54 Now the great thing with that histogram is that we can also use that histogram when we're out on the road gathering data in the cruise and transition areas of our map, just to ensure that no knock retard is happening out in the real world.