362 | Converting Your Engine to EFI? Watch This.
Summary
If you want to convert your engine from carbs to EFI there are some important decisions you’ll need to make in order to provide the right sensors and information to your ECU. In this webinar we’ll cover the process and talk about what inputs the ECU needs.
00:00 | Hey team, Andre from High Performance Academy, welcome to another one of our webinars. |
00:03 | This time we're going to be diving into what you're going to need if you're going to convert your car from carburettor to fuel injection. |
00:12 | And this is something that I've done a lot of over my career, but I think as time's gone on, it's something that has become maybe a little less prominent, I think that's probably just a sign of the times in terms of how many people are still messing around with carburetted engines wanting to convert to EFI. |
00:31 | Makes sense when we've got access to such a massive crop of quality late model EFI performance engines to start with. |
00:39 | But of course there's always reasons why you may want to convert an existing carburetted engine to fuel injection. |
00:45 | As usual we'll be having questions and answers at the end, so if there's anything that I talk about or anything related to this topic that you'd like to know more about, then please ask those questions in the chat and we'll get to those at the end. |
00:56 | Worth mentioning here as well, this process of converting from carburettor to EFI, it's exactly the same, it doesn't matter whether your engine is in a car, a motorcycle, a snowmobile maybe or a marine application really, the process of what the ECU does and the process of getting fuel and spark into the engine is exactly the same. |
01:18 | On that note, really what we're looking at here is those two elements that I just talked about. |
01:26 | It's about delivering the correct amount of fuel at the correct time and it's about delivering the spark at the correct time as well. |
01:31 | And we're just converting from a mechanical way of doing that to an electronic way of doing that, which obviously gives us a lot of control. |
01:41 | I'm going to assume that everyone watching this probably doesn't need a refresher lesson on the advantages of fuel injection over a carburettor. |
01:49 | So, we're going to break this down into a few of the key considerations that you're going to need as you go through this process and for a lot of people, the obvious starting point is what ECU should I use? That's actually probably one of the least important questions, because these days we are absolutely spoilt for choice and there's a wide range of ECUs that are all absolutely going to be capable of the job. |
02:15 | My advice here, and this isn't the area of this webinar that I wanted to focus on, my advice here is first of all, make sure that you are choosing an ECU that has the required number of injector and ignition drive outputs. |
02:30 | That's really really important. |
02:32 | So, if you've got an eight cylinder engine and you want to run individual cylinder coil on plug ignition, so a coil for each cylinder, and you want to run full sequential fuel injection, then you're going to need an ECU that has eight injector drives and eight ignition drives and these days that is obviously absolutely not a problem to find. |
02:55 | So, the only area I see people occasionally get themselves stuck with or into a problem is where they've inherited an ECU or maybe bought an ECU a bit prematurely where they didn't really know what the requirements were and they'll end up with an ECU that maybe has four injector and ignition drives instead of the eight that they need. |
03:13 | So, that's the first point. |
03:15 | Pretty much any of the popular brands that we use at HPA for our worked examples is going to be absolutely fine. |
03:23 | Really, what you need to kind of figure out here is the requirements that you're looking for. |
03:29 | So, it goes a little bit beyond just the considerations of running the engine. |
03:34 | That is relatively straightforward in most instances. |
03:38 | But what are you using the car for, is it going to be a street car or is it going to be a competition car for competition use? Do you need motorsport functionality such as maybe traction control, launch control, is the engine going to be turbocharged, what level of boost control do you need? Those ancillary functions are one of the parts that sort of separates the different brands of ECU. |
04:02 | Then we also have price point, obviously it has to suit your budget. |
04:04 | Lastly, and most importantly, I think if you are not taking on the tuning yourself, if you are relying on a professional tuning workshop to do this work for you, don't turn up buying the ECU that you found everyone on the forums was talking about and gave great reviews to. |
04:23 | I highly recommend that you purchase and use the ECU that the tuning shop recommends for you. |
04:30 | Now, they're not recommending this ECU because it's the one that they make the most money on. |
04:35 | Most tuning shops, and my shop was no different, would work with two or three main brands of ECU that covered their customers' requirements and price points. |
04:44 | And what this meant is that when you're only using two or three products day in and day out, you get really really good at using those products and you get really fast at using them, plus you learn all the little tips and tricks to get better results. |
04:59 | So, what I'm getting at here is if you turned up with an ECU that's maybe the best ECU in the world, but your tuner's never seen it, chances are that they're actually going to deliver you better results, better drivability, more power, more torque, more of all of that good stuff on a cheaper brand of ECU that they know inside and out. |
05:19 | So, always take some tips or advice from your tuners. |
05:25 | Ok, the next topic, and this really has absolutely nothing to do with the EFI conversion itself in terms of your ECU tuning. |
05:36 | This is where we get into our fuel system design because this is actually really really important. |
05:43 | So, we'll jump across to my laptop screen for a moment. |
05:46 | And things really differ when it comes to a fuel injection system versus a carburetted system. |
05:52 | So, with a carburetted system, we only really have the fuel tank , which we've got here. |
05:56 | We might have a lift pump inside the tank, maybe another external pump or only one pump. |
06:02 | And that will pump the fuel forward, in this case obviously not to a fuel rail but to our carburettor. |
06:09 | Now, the problem with this is that, well actually it's not a problem for the carburettor, with a carburetted system it runs at a low pressure, maybe somewhere in the 3-5 psi vicinity versus the 45 plus psi that we will see in a fuel injection system. |
06:25 | So, that's the first problem, the pressure is absolutely not compatible with fuel injection. |
06:31 | The other problem, which time and time again I see people kind of miss or overlook is the fact that the float bowl in the carburettor kind of acts as a surge tank. |
06:42 | So, we've got a volume of fuel that's in the float bowl at the carburettor and that's where it's then being basically drawn into the carburettor and delivered into the airflow. |
06:52 | So, at the same time we've got our fuel pump inside our fuel tank and obviously as we brake hard, go around corners, that fuel's sloshing around and it's sloshing away from the fuel pump from time to time. |
07:05 | With a carburettor application, that's kind of acceptable, because if the fuel pump sucks air for a moment, that's ok, because we've still got this float bowl full of fuel, which the carburettor can deliver to the engine until the fuel pump sucks fuel again and starts delivering that back to the float bowl to top up what it's used. |
07:25 | On the other hand, when we go to fuel injection, any interruption in the fuel pressure is going to be problematic, you're going to feel the car misfire, it can actually be quite bad for your engine as well. |
07:37 | So, it's really really critical that we maintain a consistent delivery of high pressure fuel any time the engine's running. |
07:45 | So, the normal problem we see is that someone takes a fuel tank that's designed for a carburetted vehicle, they change out the fuel pump for something that's rated for EFI fuel pressures, so 45 plus psi, and they call that good and it is not good. |
08:00 | It'll work probably quite well when the fuel tank's full but by the time you get down to maybe 3 quarters of a tank and we start getting that fuel sloshing around, we're going to be uncovering that fuel pump, it'll be drawing air and that's a real problem. |
08:13 | Easy to solve though. |
08:16 | So, all we need to do is one of two things, we can incorporate a surge tank, which is what we've got in this little graphic here. |
08:25 | Basically, this usually uses two pumps. |
08:28 | We've got our lift pump right here, which is then going to pump the fuel into the surge tank and then we've got the main pump that's going to draw out of that surge tank and then pump the fuel forward to the fuel rail, we'll talk about these other components in a moment. |
08:42 | So, the design of the surge tank, there's 100 of them out there but essentially they're all basically very similar in that they'll be a tall cylinder, maybe with a volume of maybe 1.5 to 3 litres, somewhere in that vicinity and the idea behind this is that the fuel is pumped in through the top and then it is drawn out of the bottom. |
09:02 | It's kind of a bit like the same principles behind a dry sump tank. |
09:06 | We've always got fuel above that outlet at the bottom, unless obviously we completely run out of fuel and drain the surge tank and therefore there's always going to be a supply of fuel to the main pressure pump. |
09:20 | The other option, which is also totally achievable is to go about baffling your existing carburetted tank. |
09:28 | There's a variety of ways of doing that, quite often what we'll see, if ground clearance is possible, is, or is sufficient I should say, is kind of almost a built in surge tank, welded onto the underside of that to basically retain a cup of fuel or a couple of cups of fuel around the pickup for the fuel pump. |
09:46 | There are actual baffles in there as well, always a good idea and that's kind of what you'll see in the design of a EFI fuel tank, a factory EFI fuel tank versus a carburetted fuel tank. |
09:58 | Alright, so that's the main problem that I always come across there is when people have converted without doing anything about a surge tank or baffling their fuel tank. |
10:10 | Then we've got the pumps, which I've already mentioned, we need to make sure that we are purchasing and using a EFI specific fuel pump that can handle those pressures. |
10:20 | I've mentioned their 45 plus psi, there is no sort of rock solid rule of what our fuel pressure will be. |
10:29 | There's two designs of fuel system that EFI use. |
10:32 | Up until probably about the year 2000, almost always we would see what is referred to as a return style fuel system, which is actually what this graphic is showing. |
10:43 | We get the fuel being supplied to our fuel rail here. |
10:48 | From here it comes out of the fuel rail and it goes into a fuel pressure regulator. |
10:52 | The regulator normally will be referenced to our inlet manifold. |
10:57 | So, basically what it's doing is it's maintaining a consistent differential fuel pressure across our injector. |
11:05 | So, what I mean by this is we've got fuel pressure here in our fuel rail and then the other end of the injector is inserted most normally into our inlet manifold. |
11:14 | So, what this means is that the pressure at the tip of the injector is going to vary depending on our throttle position. |
11:21 | So, if we're at wide open throttle on a naturally aspirated engine, we should have close to atmospheric pressure at the tip of the injector. |
11:27 | However, as we close the throttle, the inlet manifold pressure drops. |
11:31 | And why we want to maintain that consistent differential fuel pressure is that then, our differential fuel pressure remains the same, for a given pulse width delivered to the injector, we're going to get the same mass of fuel being delivered. |
11:44 | So, that's all about consistency there. |
11:47 | So, that's how it always used to be and then the unused fuel here as we can see, returns out of the regulator and in this particular installation it's going to go back into that surge tank. |
11:59 | Modern cars these days to simplify things run what's referred to as a returnless fuel system or a deadhead fuel system. |
12:07 | And in this instance, the fuel pressure regulator is actually most often relocated back to the fuel tank and we don't have a return, we just have a feed up to the fuel rail. |
12:18 | With these systems the fuel pressure is consistent. |
12:22 | So, normally, but again it's not set in stone, normally that'll be 4 bar, 58 psi. |
12:27 | And this time of course because the fuel pressure is consistent and the manifold pressure is varying, we now have a variable differential pressure across our injector. |
12:39 | That sounds complicated, but essentially as long as the ECU knows, which of those two fuel systems you've used, it can kind of do all of the heavy lifting in the background and basically account for the variations in fuel flow. |
12:51 | But essentially those are your two fuel system choices. |
12:55 | Which one would I recommend? Honestly, it really doesn't matter, I've used both and both will work really well. |
13:03 | What I would say is that if you are running a turbocharged engine, generally you're going to be better off using a return style system with a manifold pressure reference fuel pressure regulator, because what this will do is it will raise the fuel pressure as you come up into positive boost, maintaining that consistent differential fuel pressure. |
13:25 | If you're running a returnless style with a fixed fuel pressure, what you can find is as you raise the boost higher and higher, you start to run out essentially of effective fuel delivery through the injector, because as the differential pressure reduces, for a given pulse width, the actual mass of fuel being delivered into the engine will also drop away. |
13:48 | So, yeah, really it depends on your particular application as to how you're going to go about what your style of engine is as to, which way you want to go. |
13:57 | So, returnless does simplify things marginally but it's kind of a bit of a coin toss in my perspective. |
14:07 | Next, we need to consider the actual fuel injectors and how we're going to get those into the engine and this, along with our trigger system, which I'm going to talk about separately, these are the two more complicated aspects with an EFI conversion. |
14:23 | So, there's two main ways of converting to EFI, one is referred to as multipoint injection, which is where we have an injector for each of the cylinders on the engine. |
14:34 | Certainly, the preferable way of doing so, but generally a little bit more expensive and a little bit more work involved. |
14:42 | And then we've got throttle body injection style solutions, which I've got one here, which is a Holley Sniper, we'll just get this under our overhead. |
14:51 | These are a really popular solution for anything that runs a conventional four barrel style carburettor, so obviously pretty popular with the likes of small block sheave conversions and the like. |
15:04 | So, a common sort of bolt pattern, so it will replace a regular four barrel carburettor. |
15:12 | This one is a little unique in that it is an EFI conversion, but it's also designed to kind of be pretty stealth so we've got the injectors in here, but you actually can't see the fuel injectors and this incorporates a lot of the sensors as well. |
15:27 | So, it makes a fuel injection conversion really easy, we've got this flying lead that comes off the end of it, basically it's a case of connecting that all up and you're kind of just about good to go. |
15:40 | Obviously we've got the ignition system to consider and a few other bits and pieces in terms of getting the fuel into the engine, this is a nice quick way of doing so. |
15:49 | It also means that you don't need to change your inlet manifold, which is obviously going to save time and money. |
15:59 | So, it does work, it gets the job done, it gets the fuel into the engine, but there are some downsides with it, because you are not injecting the fuel right at the intake port , which would be preferable. |
16:12 | You also can see some discrepancies depending on the design of the intake manifold with the fuel distribution to different cylinders. |
16:20 | So, it's not exactly cutting edge and it can compromise your EFI system. |
16:27 | Basically, you're not going to get the absolute most out of it, but for a lot of people, that's also going to be more than adequate. |
16:34 | It's probably still, in most instances, going to be better than a moderately to well tuned carburettor anyway and it gives you all of that EFI control , which is why we'd be doing this in the first place. |
16:48 | Other options, which are a little bit nicer, if we jump across to my laptop screen, this is a multipoint fuel injection inlet manifold for a small block sheve. |
16:58 | So, what you can see here is that we've got now injector bosses basically machined into the inlet manifold right at the intake port. |
17:08 | It's configured for the injectors and the fuel rail. |
17:11 | We've got our throttle body up here, which we are still obviously going to need even if we aren't injecting fuel through it. |
17:18 | So, this is a much nicer, more complete solution. |
17:21 | This coupled with a trigger system and ECU that can run sequential fuel injection is really going to give you all of the functionality and niceties of EFI. |
17:32 | So, it's just a bit of a weighing up there of basically what you want versus what you're prepared to spend. |
17:42 | If you are running an engine that runs on a side draft carburettor, there are a range of other options here. |
17:49 | So, this one here's from EFI hardware but there's Gen V and probably a range of other brands as well that essentially make fuel injection individual throttle bodies that have the same bolt pattern as a side draft carburettor. |
18:05 | So, this allows you to basically remove your existing carburettors and bolt these electronic carburettors if you like straight on in their place. |
18:15 | So, nice and easy if you've already got the adapter manifold, of course these will work with any existing side draft adapter manifold as well. |
18:23 | So, a lot of control there. |
18:26 | This is multi point. |
18:28 | Obviously you've got the fuel rail and injectors that already bolt onto the top. |
18:34 | And another input that the ECU is going to need is throttle position. |
18:39 | We can see here, this is the throttle shaft, there's a two bolt flange here, we can bolt a conventional run of the mill D shaft style throttle position sensor onto the shaft there. |
18:54 | There's one already fitted as part of this combination on the Holley Sniper. |
18:58 | And that's going to give our ECU throttle position. |
19:01 | So, I'm kind of scraping the surface here, obviously the actual conversion to an EFI style inlet manifold and getting the injectors into it is going to be very variable depending on the specific engine that you are dealing with. |
19:17 | But for anything that's popular, chances are that there will be a number of companies out there that have kind of done all the hard work and have designed up an inlet manifold that allows you to mount the injectors, the throttle body and a throttle position sensor, meaning that that side of the EFI conversion becomes relatively straightforward. |
19:39 | In terms of injectors, a little outside of the scope of this particular conversation but clearly we also need to give some consideration to the size of the injectors and these need to be sized relative to the amount of power that we're expecting our engine to produce. |
19:56 | So, really doesn't matter whether we're sizing injectors for an EFI conversion or an existing EFI car, there's a lot of understanding out there on what size injectors are going to be required for a particular fuel power level application and that should be pretty straightforward to find, we cover that in our EFI tuning fundamentals course as well. |
20:17 | So, we've dealt with the fuel system and how to physically get the injectors onto the engine so we can deliver the fuel into the engine. |
20:26 | We've talked about the ECU, there are a range of other sensors that we are also going to need there. |
20:32 | The first and definitely the most important, so much so that I'm going to deal with them in their own separate section is we need to have engine speed and position sensors. |
20:43 | So, this is the most important information that the ECU relies on, it tells the ECU how fast the engine's spinning and it also tells it, which cylinder is firing at any particular time and all of the calculations the ECU makes are based on that. |
21:00 | So, we'll come to that in a moment. |
21:03 | Throttle position, which I've kind of already touched on, pretty critical, in some instances, particularly if we're running individual throttle bodies, we will actually have to use the throttle position sensor as the main load input for our fuel and ignition tables. |
21:20 | This is referred to as alpha N because the manifold pressure signal is really not useful for that purpose in an individual throttle body style manifold. |
21:30 | On top of that though, the throttle position sensor's used for a range of other aspects such as signalling to the ECU when to use idle control, as well as for transient enrichment, transient and leanment as well. |
21:45 | So, if you want your engine to drive really really nicely and replicate what we can expect from modern EFI, then a throttle position sensor is absolutely essential. |
21:56 | On top of that we're also going to want a manifold pressure sensor, we'll get this one under our overhead, this is actually a fairly old school design now, IBM style sensor. |
22:07 | So, basically these come in a range of shapes, sizes and designs but for all intents and purposes they are a three wire sensor, 5 volt, zero volt and an analogue voltage output and the voltage output is obviously scaled or calibrated relative to the manifold pressure. |
22:27 | These just need a vacuum line going to our inlet manifold. |
22:31 | Now, if we are running individual throttle bodies, I still actually do recommend using a manifold pressure sensor, although for some background fuel calculations as opposed to our main fuel table or main load input, with individual throttle bodies, gets a little bit trickier, because we actually need to take a pressure signal from each of the inlet runners post throttle butterfly and then run them into a little balance canister or balance tube and then take our manifold pressure signal off. |
22:59 | So, this kind of evens out the variations in the manifold pressure as each of the intake valves opens and closes. |
23:06 | We will also need an intake air temp sensor so again we'll get under our overhead here. |
23:13 | Not particularly tricky here, there's again a range of shapes and sizes and designs of these, some are faster acting than others but essentially they all work on the same principle, they're what's referred to as a negative temperature coefficient thermistor. |
23:28 | Simply put, they're a variable resistance, which is why there are only two wires and their resistance varies in relation to temperature. |
23:36 | To use one of these with your ECU, this does need to be connected to an analogue temperature input and what differentiates an analogue temperature input from an analogue voltage input is that it is designed for this variable resistance sensor, internally it has a pull up to 5 volts, without that pull up, this sensor won't read anything. |
23:58 | Don't have one of them here, but essentially exactly the same, we also want an engine coolant temperature sensor. |
24:06 | This is going to give the ECU information about the engine temperature, which can be used for cold start enrichment, we can use it for protection if the engine's getting too hot and we can also use this to signal when the ECU wants to switch the fan on. |
24:22 | For example, if we're going to go to an electric fan instead of a conventional engine driven fan, totally up to the individual though, either of those options for fans will be workable. |
24:35 | Alright, so that's the nuts and bolts of everything outside of this next topic , which is our trigger inputs. |
24:44 | And this gets a little bit complicated because it's going to depend a lot on the engine that we're dealing with and how we can actually go about getting this information. |
24:55 | So, in the perfect world, what we would really want is a crank trigger system, which as its name implies is a trigger wheel trigger system that is bolted to the crankshaft in some way, shape or form. |
25:08 | The reason for this is that that is going to give us the most accurate engine speed signal because we are getting that speed signal directly from the crankshaft. |
25:17 | It's quite common to instead take this from the distributor, which is run at half engine speed but there are some downsides with this in terms of the amount of free play in the distributor, it can move around, it can have resonance, it's not directly linked, because it's reduction driven, it's not directly linked to the crankshaft so there is a little bit of variation. |
25:43 | Now, is that going to be a problem? In most instances, absolutely not. |
25:48 | It's only really when you're starting to get into the more powerful engines that are running at higher RPM where the accuracy of the ignition timing is absolutely critical that we don't really want any chance of our timing drifting around by a couple of degrees, because that could be enough to do damage. |
26:04 | So, again we'll go to our overhead here, this is a trigger disc that's been homemade but a bit of an example of what can be done. |
26:13 | And we've got, I think this is a 60-2, I can't count these that quickly to guarantee it but essentially this will go on the crankshaft and we can see here we've got this gap of two missing teeth and why that's important is that the ECU can detect that gap in the teeth and that tells it essentially where the crankshaft is in its rotation. |
26:37 | This gives us most of the information we want, but not all. |
26:41 | So, this will tell the ECU whether the crankshaft is at TDC on number one or bottom dead centre, what it doesn't tell us is whether it's on TDC on the compression stroke or at the top of the exhaust stroke because of course there are two full revolutions of the crankshaft for every engine cycle. |
27:01 | So, for complete information we also need to get an input that works at half engine speed. |
27:06 | This can come from the camshaft or it can also come from the distributor, because of course the distributor works at half engine speed. |
27:14 | So, those are the two pieces of information we really need. |
27:17 | To give you another example of what another trigger disc looks like, this one is off a Kawasaki jet ski engine I think from memory. |
27:27 | So, again goes on the crankshaft, evenly spaced teeth and this one would also include a cam sensor that gives it the synchronisation or engine position. |
27:37 | Now, you can make your own, but again if you're dealing with popular engines, if we jump across to my laptop screen here, this is just one brand here from Holley that make crank trigger systems that are literally bolt on for a range of engines that are popular for EFI conversions. |
27:57 | So, you can often find something off the shelf that I absolutely would recommend. |
28:03 | Unless you're really handy with maybe a mill and Solidworks or Fusion and you really want to make your own parts, obviously in some instances if you're dealing with something that's a little bit more out of left field and there isn't a lot of support in the aftermarket, at that point you may have no option. |
28:23 | But there are a few other solutions. |
28:26 | As I mentioned, the best technique is to have a crank trigger with a synchronisation or home input based on the camshaft or the distributor. |
28:37 | That's going to give the ECU really clean information about engine speed as well as engine position. |
28:42 | This will be essential if you want to run, or this style of input with engine speed plus position is essential if you want to run full sequential fuel injection where we can time each of the injector's openings to the phasing of the intake valve as well as direct spark where we can have an ignition coil for every cylinder. |
29:03 | However, we can end up running a slightly dumbed down system , which is probably still going to be significantly superior to most carburetted combinations where we only have something like this on the crank, we've got the missing teeth so again it knows where abouts in the engine cycle it is or whereabouts in the engine rotation it is, but it doesn't know whether it's on the compression stroke or the exhaust stroke as the example I gave before. |
29:35 | In that instance we're sort of restricted to running batch fire fuel injection where the injectors are all operated together or split in groups. |
29:42 | So, some will be injecting against an open intake valve, some will be injecting against a closed intake valve and likewise we're restricted to either a distributor ignition system or alternatively we can run waste spark style ignition, where we fire one coil on the compression stroke and the other coil, the opposing coil will be firing on the exhaust stroke where essentially that spark does nothing , which is why it's called waste spark. |
30:09 | So, that solution is definitely not my preference, but it is much simpler and of course a little bit more cost effective to go down that path. |
30:19 | So, if you are on a budget then that is a solution that's definitely a possibility. |
30:25 | I do find that once you're sort of outside of the idle and very low RPM cruise, that the batch fire fuel injection actually becomes really kind of irrelevant. |
30:38 | It can make idle tuning, particularly with larger injectors, a little bit trickier but really once you're outside of that idle zone, it's much less of a consideration. |
30:47 | We're going to go into questions and answers really soon so if you've got anything on anything I've talked about so far then please ask those in the chat now, we'll get into those in a second. |
31:01 | One of the other problems we will come across is with a lot of carburetted engines, particularly older ones, they will run a mechanical distributor. |
31:12 | So, if we jump across to my laptop screen, I'm not going to try and explain how this works in detail but essentially the relationship of where the spark is occurring versus rotation of the distributor is going to depend on engine speed and vacuum. |
31:29 | So, basically there's mechanical weights, which work on centrifugal force so the higher the engine speed or the distributor speed, the more they move and that can advance the timing and likewise we've got a vacuum advance canister here so this can advance the timing at lighter load where there's more engine vacuum. |
31:47 | So, this is kind of a tricky way of trying to build up a full 3D spark curve related to both engine speed and RPM. |
31:56 | We do this all the time with fuel injection and it's no issue but much much trickier to calibrate something like this to get exactly what you want. |
32:06 | The problem is if we are going to retain a distributor and we're converting to EFI, we absolutely would want to get rid of this mechanical advance weights and the vacuum advance canister. |
32:22 | This is really a bit dependent on the specifics of your distributor, I've only ended up having to do this a handful of times, which is, I actually count myself fortunate, but basically what we need to do is find a way of locking this system up. |
32:35 | Usually, this is simply going to incorporate a few strategically placed dobs of MIG weld, basically making sure that the mechanical advance system is disabled. |
32:45 | And why we want to do that is that then the ECU is triggering the igniter to the coil and that's going to then decide when the spark is actually delivered to the cylinder that's firing at the time. |
33:00 | Now, yes you could of course run electronic fuel injection with just the ECU controlling the fuelling and leave the conventional mechanical distributor to do the spark, but we'd be giving away a lot of the advantage that fuel injection has, so I'd absolutely recommend going to a fixed distributor using the computer to provide the spark. |
33:24 | Now, of course again for popular vehicles, there will be off the shelf distributors available that will provide what we need for an EFI system. |
33:34 | The other solution here is often these will incorporate a trigger disc or trigger discs inside of them, which kind of fixes our trigger system problem that we were talking about earlier. |
33:46 | Again I mentioned having your trigger system inside of the distributor is not the perfect solution but it's absolutely workable and is obviously going to be much cheaper than actually changing your distributor plus also purchasing a crank trigger kit. |
34:01 | Right, we'll jump into some questions and again if you've got more, please keep them coming. |
34:08 | First question comes from Two Tons of Light who's asked, "What do you think about the Holley fuel mat?". |
34:20 | I'd actually forgotten about that product until you've just asked about it. |
34:23 | We saw it at SEMA many years ago, we've never had the opportunity to actually use it ourselves. |
34:30 | It kind of looks like it's actually magic. |
34:33 | If it works as well as the promotional videos suggest it does, then yeah it seems like a really really good solution to fuel surge. |
34:41 | For those who have no idea what we're talking about here, I would suggest jumping on Holley's website or YouTube and search up Holley fuel mat but yeah really nice solution. |
34:51 | We did look at this for one of our Toyota 86s, which obviously is already a fuel injected car, but in a race application we find that the factory fuel system suffers from really chronic fuel surge and it was just a little bit too difficult to get what we needed when we needed it so we went with a conventional fuel surge tank. |
35:14 | Alright, we've got a couple of questions here, I'm going to leave these, because they're not relevant to today's topic, I do apologise, but we try and keep all of our questions on these absolutely on the topic, so that when our members review these in the archive, it kind of keeps everything together. |
35:33 | So, it looks like that's all the questions we've got for today. |
35:36 | As usual if you are watching this at a later point in the archive, then if you've got further questions, please ask those in the forum and I'll be more than happy to answer them there. |
35:47 | So, hopefully we can see you next week. |
![](/resources/themes/base/production/images/contact-popup-taz.jpg)