Practical Standalone Tuning: Step 4: Base Ignition Timing/Fuel Pressure

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Step 4: Base Ignition Timing/Fuel Pressure

07.18

00:00	The last step before we can actually start the engine for the first time is to set our base fuel pressure and our base ignition timing.
00:07	With our Evo running a completely stock fuel system, there's really nothing to do here in terms of our fuel pressure.
00:13	Typically, engines like this with a return style manifold pressure reference fuel pressure regulator will typically run a differential pressure of 3 bar or 43.5 psi.
00:24	This is important because this does essentially decide on what our injector flow rate is going to be which as we've already discussed is an important aspect of the VE based fuel model.
00:36	Even though we don't have any adjustability, it can be beneficial to at least test and confirm what the fuel pressure is, that way of course you can then correct the injector flow data as required.
00:47	In our case with nothing to do we'll move on and discuss our ignition timing.
00:51	Now, the process of setting our base ignition timing here is to essentially align the numbers that we're seeing on the laptop screen with what we're actually receiving at the spark plugs and this needs to be done with a timing light.
01:03	Because we haven't actually got the engine running at this point, this is going to be dealt with in two separate steps.
01:09	First of all, we'll check the ignition timing at cranking speed, just make sure that we're at least in the ballpark.
01:15	Then once we've got the engine up and running a little bit later in the process, we can come back and revisit this at idle or raising the RPM, maybe about 2000 to 3000 RPM actually, will give us a more stable idea of what our ignition timing's actually doing.
01:29	So, it's really important to make sure that we coarsely set the ignition timing now, then come back and fine tune this later on once we know the engine's running properly.
01:38	The reason we can't get this fine tuned right now is that at a cranking speed of 150 to 250 RPM, we are likely to see our ignition timing jumping around a little bit, it's not going to be rock solid, so for this part, don't beat yourself up too much, if you're within about 2 to 3 degrees, that's going to be absolutely fine.
01:57	This also does really need to be achieved with a helper.
02:01	Generally, we're going to have someone watching the timing with a timing light in the engine bay and then someone on the laptop actually making these adjustments.
02:10	Let's go through what's involved inside of our NSP software.
02:13	So, we're going to start by coming to our ignition tuning menu here and we can see that we've got this lock mode selected here and typically we would have this set to disabled.
02:25	What that means is that when the lock mode is disabled, the ignition timing is going to come from our ignition tables plus any corrections that may be applied.
02:35	So, if we look at our drop down menu here, we're going to select always on.
02:39	Now, we see that that also does bring up a little hazard symbol here, this can be problematic if we forget that we've done this because of course we will be running with a fixed ignition timing irrespective of load and RPM and we can be making adjustments to our ignition table and wondering why it's essentially having no effect.
02:56	Next we have our firing angle.
02:58	So, this is where we're going to set the actual ignition advance that the ECU is going to be delivering and what we want to do here is choose something that's going to be suitable so, we can actually see it.
03:09	It depends on the engine, a lot of engines will have multiple timing markers, maybe TDC, 5, 10 and 15 degrees, some will only have a TDC marker or in some instances there may be no, marks at all and you may need to make your own in which case we again will be left with just a TDC marker.
03:27	Now, a point to make here is that while we're setting our timing at cranking, it really doesn't matter what we choose here, zero degrees or TDC will be just fine.
03:37	However, we may find that once the engine's up and running, it might struggle to run or idle nicely if we are choosing zero degrees.
03:45	So, we need to consider that, if you've got no other timing marks other than TDC, that's really going to be sort of defining what we have to look for and here we may need to use a little bit of throttle to keep the engine running happily and bring that RPM up to that 2000 to 3000 RPM vicinity.
04:02	So, for the moment we'll leave that at zero degrees and what we need to do then is come across to our trigger system menu here and we are going to be adjusting this parameter here, our TDC angle until the numbers that we're seeing on the laptop screen, or zero degrees in this case, matches what we're actually seeing with our timing light.
04:24	So, in this case because again we're starting with a known trigger mode and a base map and there's no real ability to move the timing around in terms of the mechanical components, it's not like there's a distributor or a cam angle sensor that can be rotated.
04:38	We've got a fixed crank trigger on the crankshaft and we've got a fixed camshaft position sensor on the cam.
04:45	So, typically with a base file like this we should be able to expect the TDC angle to be correct, but of course trust, but verify, we always want to actually check this ourselves and there can be sort of variations here of maybe a degree or two each way based on manufacturing tolerances.
05:02	OK, before we crank the engine here we're just going to come across to our fuel system here and again we're just going to disable the injectors and we're going to reboot the ECU to make that change take effect and again just as we've already looked at, that's going to prevent the engine starting.
05:18	So, from here it's a case of cranking the engine and looking at the timing with our timing light and then making adjustments to that TDC angle until the two align, remembering at cranking we're probably unlikely to get this perfect and it will move around a couple of degrees.
05:34	Once we're happy that we've got the timing where we want it to be, we can come back to our fuel system, re enable our injection, reboot the ECU and then what we want to do is come back to our ignition tuning and we want to make sure that we turn our lock mode back to disabled and that again will just allow our timing to track the actual values in our table.
05:56	So, at this point we've got our fuel pressure checked and set, we've got our base ignition timing at least close enough that we should be able to get the engine to run and we're ready to move on.
06:06	I will make one more point here though because we do have two full engine revolutions per engine cycle and if you're running a direct spark system, what this can mean is that the timing will appear to be in the correct place, but it'll be one engine cycle or 360° out.
06:25	So, how we can fix this is we can come back into our TDC angle here and we can either add or subtract 360° from this value, that will give us the exact same timing, but just on a different engine cycle, the correct engine cycle.
06:39	This will become apparent when we try and start the engine for the first time.
06:43	If the engine appears to maybe be occasionally popping out the exhaust, this is a good indication that our base timing may be one engine cycle out.
06:52	So, that's just something to keep in the back of your mind.
06:55	In our particular case with the Evo 9, given that it runs a waste spark ignition system, this is not going to be relevant because essentially we're going to be firing on both the compression and the exhaust strokes anyway, so wherever we see that flash, as long as it is on our timing mark, that's going to be the correct location.
07:13	Let's move on with the next step of our process.