- Hey guys, it's Andre from High Performance
Academy here, welcome to another one of our webinars where this time we're going to
be delving into transient enrichment on the Haltech Elite 2500 platform. This will also translate across to any of the
Elite ECUs. Now transient enrichment is one of those
topics that I know a lot of enthusiasts and professional tuners alike struggle with. It can be one of those things that really does
make the difference between a car that's nice and smooth to drive just like a factory
tune and one that's absolutely terrible, bunny hopping and hesitating every time
you stab the throttle. So it's one of those things that we really want
to focus on getting right, it can make a massive difference to the enjoyment of your
car. If it's a racecar it's also going to make the car
potentially quite significantly faster and easier to control out on the racetrack. Now the reason that a lot of people I think
struggle with transient tuning is that it can be a little bit challenging to understand
first of all what is actually going on inside the engine and why we require transient
enrichment or additional fuel on a throttle input anyway in the first place. And I think just like anything, if we don't
understand what's going on, it's really hard to wrap our head around the
correct approach to fixing that problem or tuning out that particular problem. The other aspect of course here is that it's
important to not only understand what you're trying to do, it's important to
understand the correct technique or correct process to go through in order to
optimise each paramter in turn, in the right order to get the right result. Now as usual, we will be having questions
and answers at the end of today's lesson so if there's anything I talk about here that
you want me to dive into a bit more detail on please feel free to ask those questions
in the chat. Alright so what we're going to do is start
with the basics of why do we need acceleration enrichment in the first place? And this also really coincides with while
we're talking here about enrichment or additional fuel when we stab the
throttle, what we're also going to find is that if we are at high load and then we
tip out of the throttle or close the throttle sharply, we're going to see exactly
the opposite situation where the air/fuel ratio will momentarily go quite rich. So it's actually an acceleration enrichment
and a deceleration enleanment situation that is occurring. So in order to understand this, what we're
going to do is start by heading across to my laptop screen. Now for anyone who wants a little bit
more understanding, a little bit more detail around this, I'm only going to be
covering off the key topics here. This is actually a slide taken out of our
EFI Tuning Fundamentals course, so if you own that course, head across,
there is an eight minute long module on transient enrichment so it goes into a
lot more detail than I'll be going into here. But essentially, as you can see, we've got
a cut away of our intake port here. And I just want to explain what's actually
happening inside the port because it probably doesn't go quite like you'd
expect. So of course we've got our fuel injector
located here and it's spraying the fuel down into the intake port. We've got our valve, our valve is located
over here of course as well, the intake valve, opening and closing,
allowing the fuel and air to enter the port. And most people think that when the
fuel is injected, it simply all enters the combustion chamber and is burned. And that's actually not quite the
situation we get. Instead what we end up with is this
film of fuel that sits on the port wall. So this fuel film actually involves quite
a reasonable volume of the fuel being delivered by the injector. And the size of that fuel film is constantly
changing. The size of that fuel film will be affected
by the air speed, the air temperature. A really big factor of the size of the fuel
film will be our air pressure, so our manifold absolute pressure. And it's also going to be affected by things
like our port temperature as well. So under steady state conditions when we
are tuning, the effect of the fuel film is basically insignificant because what's
happening is that the fuel is being delivered by the injector, it's being used to top up
and establish the volume of that fuel film, but once we're under equilibrium or steady
state conditions, what's going to happen is that that fuel film will start to evaporate
off so the heat of the cylinder wall will essentially vapourise that fuel off the port
wall where it's then introduced back into the intake or into the combustion chamber. You're also going to get droplets that will
fall into the combustion chamber in a liquid format. So essentially what I'm getting at here is that
under steady state conditions, the entire volume of fuel that is delivered by the
injector does make its way into the combustion chamber, but it's in a round
about way. Some of the fuel goes to topping up that
fuel film as some of the fuel film is vapourised and enters the combustion
chamber. So under steady state conditions, don't
really need to worry too much about our fuel film, it has no effect. Where it really does have a big effect though
is under transient conditions. And if we take, for a moment, the RPM out
of the equation, we're at a steady RPM and we're at light throttle, what we're going
to have is a relatively low air pressure. What this results in, with our low air
pressure is our fuel film will establish, I can't tell you what size it's going to be,
because that's going to depend on so many factors specific to your engine. What's important to understand is that
when we go from basically a closed throttle, steady state conditions and we mash that
throttle open, the manifold pressure understandably is going to rise really
sharply. As that manifold pressure increases
sharply, what happens is that the size of the fuel film will increase. So what we then have is a situation where
momentarily the fuel that's coming out of the injector, instead of being injected
and then making its way into the cylinder, what it does is it goes into increasing the
size of that fuel film. And at the same time, while that fuel film
is increasing in size, we've got less of our fuel vapour being vapourised off,
our fuel being vapourised off I should say. So essentially for a very short period of
time until that fuel film reaches equilibrium again or it reaches a constant
size, the fuel or a portion of the fuel that's being injected, actually isn't making its way
into the cylinder, instead it's being used to increase the volume of that fuel film. So this is why we see a lean condition during
tip in, even when our fuel table or our VE table is correctly calibrated. Now we get exactly the opposite situation
occurring when we tip out of the throttle. So we're now at high manifold pressure,
wide open throttle, we're still at 2000 RPM, we take our foot out of the throttle and what
we find is as the manifold pressure decreases, we get the exact opposite effect. Now what's happening is that the size of
that puddle or fuel film on the port wall is going to decrease. And in order for it to decrease, it doesn't
need to be topped up by the injector, so now we get an excess of fuel entering the
cylinder, some of the fuel is still vapourising off our fuel puddle or fuel film,
it's entering the cylinder, but now because the fuel from the injector isn't necessary
to top up that fuel film, we're also getting additional fuel from the injector
going into the cylinder and that ends up with our engine running rich. So that's the sort of situation that
we're likely to see. Now what we'll find is that there are
a number of ECUs out there in the market now which actually attempt to properly model
the size of that fuel film in order to basically model the required additional fuel under
tip in and reduce the fuel under tip out or decelleration. The MoTeC M1 is one example, there is an
option to run this in the MegaSquirt ECU as well. When set up correctly, understandably it can
do a pretty great job. But the problem is, it's quite complex, it's
quite difficult I think for a lot of tuners to get their head around and it requires quite
a lot of fiddly work in order for us to do a good job of that. So for this reason, the majority of ECUs
still work on a relatively basic strategy when it comes to transient enrichment. Essentially the options we've got available
are to use the throttle position sensor as the parameter to activate acceleration
enrichment, or alternatively we can use manifold pressure. So that's what we've got in the Haltech Elite
ECU. What we'll do now is we will head across to
our Elite ECU and we'll have a quick look at a couple of aspects first. So what I've got here, just for the purposes
of this demonstration, I've actually added in a little time graph here and I
find that this is quite a nice easy way to visualise what's going on when we are
tuning our transient enrichment. This is just logging our wideband air/fuel
ratio over time. We can see it's moving around a little bit
because right now while I'm just talking, I've just got the air conditioning running so
that's why we can see it sort of moving a little bit rich and a little bit lean at idle. When we get into this I will disable the
air conditioning so we don't have anything upsetting what's going on. So before we attempt to tune our
transient enrichment, and I think this is probably the area that most tuners sort
of go wrong to start with, it's really important to understand that our
transient enrichment parameters basically act as an adder or multiplier
over and above the existing or main fuel injector pulse width anyway. So in a round about way what I'm saying
is we need to actually start with the basics which is making sure that our fuel table,
or in this case our VE table is correctly calibrated, correctly tuned. So what I mean there is that there's no
point trying to chase down a lean hole, let's say we're at 4000 RPM and we're at
cruise so we might be down somewhere around about this area, minus 60 to
minus 50 kPa, we smash the throttle, the manifold pressure's going to increase,
in this case we're turbocharged so we might momentarily end up somewhere around
about 20 to 40 kPa after we initially smash the throttle open before the turbocharger
starts building boost. So what's important here is to make sure
that under steady state conditions, we've done a really good job of thoroughly
filling in all of the area that the ECU is going to access so basically we're going to
be moving through about that slice of the table there. So I want to make sure that each of those
individual cells has been properly calibrated under steady state conditions. Remember under steady state conditions,
that fuel film plays no role because it's been topped up at exactly the same rate
that it is being vapourised off as well and entering the cylinder. So if you don't have this right, you kind
of get into a situation where you're chasing your tail, you might have a lean
hesitation or something like that on tip in and you're trying to fix this with your
acceleration enrichment but the real problem is that you might have a lean hole
in your fuel map and essentially in order to try and combat that, you've got to
overcompensate with the acceleration enrichment, then you get to an area where
your fuel table's actually right and now your acceleration enrichment is overkill
and you're all of a sudden too rich. So this is the most common problem,
trying to fix issues in your VE or fuel table with your transient enrichment. Don't do that, get your basics right first,
tune your fuel, tune your ignition, once you've got those right, then you can
start moving on to your transient enrichment. Now I've talked here about the transient
enrichment and transient enleanment. So as we tip out removing fuel. The other aspect that is worth considering
here as well, I think probably in the 18 odd years I've been in this industry now I've
only needed to use this on about three engines but I'll deal with it, which is
transient ignition trimming. Now obviously just what I've said there,
it is very rare in my own personal experience to need it. I have had a couple of turbocharged
race engines where for no obvious reason, on tip in at medium RPM, so let's say
4000-5000 RPM, where we are in a situation where the turbocharger can produce boost
very quickly, we'll find that on a sharp throttle input the engine suffers momentarily
from a couple of hits of detonation, you can audibly hear that. Now despite that happening, if we go back
and steady state tune all of those ignition cells, under steady state conditions we see
no knock occurring. So again, rare but some ECUs including the
Haltech Elite do give you the ability to retard the ignition timing as required. Alright so what we're going to do now is
go through and have a look at the setup for some of these parameters. So what we want to do is start by heading
across to our main setup. And we're going to be on our functions menu
which we're already on and we can see we've got our transient throttle function. Obviously if you want to use that, you're
going to need that enabled. So we'll go through each of the settings. And to start with you can select your load
type. So the options there, we can use our throttle
position or manifold pressure. In almost all instances, I've found better
results using a throttle position sensor. The only time that I would consider manifold
pressure is if you simply don't have a throttle position sensor. It's been a long time since I've even tuned
an engine where no throttle position sensor was included, it's one of the, basically what
I'd consider an essential input sensor, can't really do as good a job without that
throttle position sensor. So by all means, try each option but
generally in my experience you're going to get a better result using throttle position. Now we also have the ability here,
we've got a little tick box for enable disenrich so this is Haltech's term for tip
out enleanment or in other words, removing fuel when we back out of the
throttle. So you can see that I've got that enabled
there, that's absolutely up to you. What you will find is that while the
engine is incredibly sensitive to transient enrichment on acceleration,
so when we tip into the throttle, if that isn't right you're going to feel
the car hesitate, it's not going to be smooth, it's going to be horrible to drive. Generally the engine is going to be much
less sensitive to that overly rich situation we see on tip out. So while it's nice to have everything
rock solid, do the job as well as we can, it's definitely not as important with the
disenrichment as it is with the tip in enrichment. We've also got the ability to enable an
overall correction which I am not using in this situation. We're going to go through our enrichment
parameters, so what we've got available here. Now if you do need more information on
this, it is all available in the Haltech information but I'm just going to explain it
in my own language here. So the first thing we've got here is our
load rate deadband. You can see this is at 20% per second. Pretty straightforward, basically is defines
a value or a rate of change of our input, throttle position or manfold pressure
depending which we've selected, which we need to be above before the
Elite ECU will actually allow any transient enrichment. Now this is quite important and it's
actually something that's tripped me up, not with the Elite, but with a couple of other
ECUs where essentially this deadband was a little too small, a little too sensitive and
particularly with some older engines, we may find that as the throttle position
sensors age, they can be prone to a slightly erratic signal and what this can give if
we've got the sensitivity set too high, basically under steady state conditions,
we might be getting momentary hits of acceleration enrichment so you might
be wondering, why under steady state conditions you're seeing erratic
air/fuel ratios, this can be why. It's always a good idea for this very
reason to actually inspect or log your acceleration enrichment paramenters
so you can see if you're getting uncalled for accel enrichment. Off the top of my head I think the parameter
I'm using, the number that I'm using here, 20% per second, is pretty close to the default
Haltech value so there or there abouts should be a good place to get started. The next parameter which is our load
acceleration dead band. Now not a particularly well explained term
in my opinion. Let me break that down, essentially this
is a decay parameter. So basically it defines how quickly the
additional acceleration enrichment fuelling can be removed and you can see this is
in percent per second squared or percent per second per second. So basically in this case it's allowing
100% of the fuelling to be removed per second. So the smaller the number you put in
there, the longer the acceleration enrichment will remain active,
the bigger the number the quicker that acceleration enrichment will be
removed. Next we've got our detect duration and
this is essentially a filtering if you like, so how long the signal must be active
above that parameter for before any transient enrichment will be added in. So the danger here is if we set this too
high, it's going to naturally create a latency before any transient enrichment
will be used. So you want to keep this as low as you
can, you can see that I've got one millisecond. We've got our ignition correction decay
time, we're not going to be talking here much more about our ignition correction
but that, as its name implies, is how long our ignition retard will be
decayed over, in this case, 500 milliseconds or half a second. Now the next aspect here, our little
tick box, our little enable box for enable Async, so this is another thing that
I think is probably in my experience peculiar to the Haltech platform. When it comes to the acceleration
enrichment there's two ways you can add it in with the Haltech platform,
through either synchronous or asynchronous transient enrichment pulses. So let's break that down and explain what
it means. So normally in almost all instances,
we will be able to use just the synchronous acceleration enrichment and what that
means is that basically the existing injector pulse widths are extended. So the amount of normal fuel that will
be injected, let's say that that might be a six millisecond injector pulse width,
all the ECU does is just extend that six millisecond pulse width to provide
whatever additional fuelling that is calculated to be required. So this is timed with the existing injection
events. Asynchronous on the other hand gives
you the ability to actually add additional injection events. So we then have the option of both
synchronous and asynchronous, can get a little bit confusing and just a
couple of times I have played with this, it can be a little bit hard or a little bit
challenging to know where best to add your acceleration enrichment, do you do
it with your asynchronous or your synchronous enrichment? Don't worry if that's already scared you
off, the reality is that in 99% of situations, you're going to get away just find solely
using the synchronous acceleration enrichment, this is also how the majority
of aftermarket ECUs deal with their transient enrichment. The couple of times where asynchronous
can be an advantage would be peculiar engine setups. Maybe you've got a situation where the
injectors are fitted a long way away from the intake ports, obviously under that
circumstance there is a transport time for the fuel to actually be delivered to the
cylinder. So it can actually be an advantage for the
ECU to provide straight away some additional injector pulses to get that fuel delivered
into the combustion chamber as quickly as possible. So rotary engines and engines where the
injectors are a long way away from the ports, probably about the only times you really
need to worry about the asynchronous injection. We've got the disenrichment which is
essentially the exact same parameters that we've looked at with enrichment, this time
just removing our fuel. So those are our key parameters. Now important to understand here that the
default values from Haltech are going to be a pretty good place to get started and it
seems from my experience so far with Haltech that if you have got your main
fuelling under control with your VE table then the default values are actually
going to provide you with a pretty good starting point for getting the fuelling
dialled in. Alright so what we can do now is close
that down and now that we've got those parameters discussed, we can move down
and we can actually have a look at the transient throttle control parameters here. We'll find these in our ECU navigator
out on the left. So we obviously have our parameters for
enrichment, we've got enrich rate, enrich amount synchronous and we've got
our ignition correction. We've also got our disenrich rate, disenrich
amount and importantly here we've also got a coolant temperature correction. Now I'll just touch on the coolant temperature
correction first because it is relatively easy to explain. Essentially all we need to understand here
is that the size of that fuel puddle, the fuel from on the port wall is also
going to be affected by the port temperature, I mentioned that when we were looking
at that little slide of what's going on in there. So what we need to understand is that at
cold startup when the engine is warming up, we are going to require additional
acceleration enrichment so that's what this table is enabling us to do. We can see that this is a two dimensional
table versus our engine coolant temperature. And we are simply increasing the amount
of fuel added through our transient enrichment as our engine cools down. So the way we go about doing this is we
would start with our engine at operating temperature, we can see that
that's where we are now, we're sitting up above that 80 degree site, actually at 95°C. And we want to start by dialling in our
transient enrichment parameters with the engine at operating condition. Once that's done then we can come back,
do a cold restart and we're obviously, depending on our ambient temperature,
going to be somewhere down in the lower cells of this table and we can manipulate
those as required if we've got too much or too little transient enrichment. So this is the table that we're going to
deal with last. Let's head across now and we'll have a look
at our other parameters. So we've got our enrichment rate. So it's really important just to understand
what these tables mean and the interaction between these tables. So starting with our enrichment rate here. This is how quickly the fuelling is going to
be delivered. So actually it works in conjunction with our
enrichment amount, the two tables, two parameters are multiplied together
to give us the final amount of additional fuel. And what we need to understand here is that
this table, we've got our current throttle position on the vertical axis and we've got
our rate of change of throttle position on the horizontal axis. So if I just move through this table we
can see we do have a little blue circle, I'm trying to highlight in red over the top
of that, not working too well but let's try that again. You can see we've got our little blue
circle showing where abouts we're accessing. So at the moment this is drive by wire so
we're sitting at around about 2.5 - 3% throttle in order to make the engine idle at 800 RPM. So as I increase my throttle opening we
can see that we're going to end up moving up through this table. Got a little bit of latency in that. We moved up through that table just a
little bit there. And what that allows us to do essentially
we're going to need more transient fuelling when we are at a closed throttle. So if we mash the throttle to the floor from
closed throttle, we're going to need to add more fuel than if we were already at 70 or
80% throttle and we just smashed the throttle the rest of the way. So the other access here, this is the rate of
change of throttle so again the more quickly and more aggressively we open the throttle,
the more fuelling we're instantaneously going to need. So again if I just smash the throttle open,
hopefully what you're going to be able to see is that that little blue circle's going to move
out here to I think, depending how quickly I do it, around about 200%,
so let's just try that. OK did exactly that. Alright and at the same time just to show
that we need a little bit of work here, we can see we've got this big dip rich in
our fuelling. So that's how this particular table works. So it gives us the ability to add more
acceleration enrichment down where we need it which is where we've started from
closed throttle and we've been really aggressive with our throttle stab. If we've started from a high throttle
setting and we've only just moved the throttle slightly, we can see that we've got
much less down to basically no acceleration enrichment. So this table, as I said, works in conjunction
with our next table which is our enrich amount synchronous. Two dimensional table this time relative
to engine RPM. And essentially within this table we are
defining how much additional fuel is going to be delivered and this as I mentioned
gets multiplied by the value from our enrich rate to define the final amount of fuel to be
delivered. Sounds a little bit complex but when you
actually go through the process, reasonably easy. Just need to understand the interaction
between those two tables and in other words where abouts you want to make your
adjustments. Now we've done a similar webinar on this
topic in the past and one of the questions that came up was why are the numbers as
they are in this table? Generally what we find is that with
acceleration enrichment in any ECU, standard, factory or aftermarket, what we
find is that the amount of additional enrichment is the most, or required I
should say, is maximum at low RPM. And as the RPM increases we generally find
that we need less and less transient or acceleration enrichment. To the point where generally once we're
past about 4500, 5000 RPM, we need little to no acceleration enrichment just
due to that fuel film. So this seems to be a little bit counter
intuitive because we can see here our numbers are actually maximum at
high RPM. This is a relatively default table and you
can see the numbers in there from 4000 RPM and above, 160%. So in order to get some clarity on this and
make sure that I am giving you completely accurate information, I actually went to the
trouble of having an in depth chat with the tech team at Haltech earlier today. Now this is a little bit complex and there's
a few things to understand here but essentially what it's explained is that this
is a pseudo VE number. So this is looking at an assumed volumetric
efficiency number from the engine. So understandably as our engine RPM
increases, our volumetric efficiency also increases, within reason. It's not going to increase forever. So that's why we start seeing those numbers
actually increase with RPM rather than decrease like we'd traditionally expect. Now I have used that term pseudo VE. So it is not a true VE number, it just
works in essentially the same way as a VE number and that's why we've got that
default value. So again, the default value's not a terrible
place to get started and what I would suggest is that provided you've got your
volumetric efficiency table dialled in properly, what I'd do is start by making
wholesale changes to the entire table, rather than trying to tune individual cells. What we can do is we can find that by
increasing or decreasing the overall table, generally this is going to be enough
to get us into the ballpark of where we need to be. Alright we're going to go through a quick
tuning demonstration and once we've gone through this, we're going to get into our
questions so if you've got any other questions right now, this is a good time to
remind you to ask those. So what we're going to do here is we're going
to start by getting up and running on our Mainline dyno and we're going to come up
in fourth gear here to 2000 RPM and we're just going to get running under steady state
conditions. And what I'm going to do is come up to a
point where let's say we're at around about, let's say try and get us to about -15 kPa. So light load here and what we want to do
is initially just wait until our engine has stabilised, reached equilibrium, we can see
that our measured air/fuel ratio here, sitting between 14.6, 14.7:1, we've
obviously got pretty good control over that right now. And that's being shown also in our time
graph to the right with a nice flat line. So the next process here, I'm going to
simply stab the throttle, I'm going to move it as quickly as I can to wide open throttle. When we're starting with our transient
enrichment, I always start with the largest, sharpest throttle change I can initially and
then work back from that. And I'll explain why that's the case in
a moment. So what we're going to do is we're just going
to stab the throttle and we're going to look at what happens to that time graph,
let's do that now. OK so that's actually not been too bad,
so I'll just back off and we'll look at it. Unfortunately I can't pause it there but what
we saw is that initially on that stab, we went from 14.7:1 up to about 15-15.5:1
thereabouts. Now it is important also to mention here that
we are going to be using our air/fuel ratio plot as a metric when we are tuning our transient
enrichment. However to me that's actually not the most
important aspect. What I'm looking for above all else is smooth
and crisp response to the throttle input. So actually while you wouldn't have been able
to notice this from the other side of the GoPro, the car responded crisply, there was
no hesitation, everything was nice. So I already know that I'm pretty much there
or thereabouts in terms of that fuel tuning but what we did see was that the air/fuel
ratio moved a little bit lean before the boost started to climb and then we saw the air/fuel
ratio dip down and get back to where it should be for the sort of load we were
seeing. Now the other aspect that goes hand in
hand with that is even when our transient enrichment is dialled in really really nicely,
we're almost always going to see a brief lean spot on that initial tip in. Now again over my experience with 18
odd years in a career now, I would not suggest trying to chase a situation where
we get a perfect line from our partial throttle, low load air/fuel ratio, down to
our wide open throttle. If we do that, generally you're almost
certainly going to end up putting in excessive fuel and while on a graph it
might look nice and crisp, nice and clean, generally I find that that actually results
in a doughy response from the engine. So remember the key parameter that you're
looking for, the key metric is how does the engine feel, how does it actually respond
to that throttle input and if everything's nice and crisp and you've got that slight
lean spike, happy days, I'm quite OK with that. Alright let's go back to our same operating
point, so we know that we ended up going a little bit lean there, little bit
leaner than I'd like, we'll try and get back to our same operating point and we'll
go back and try and get into steady state conditions there. Now we are at 2000 RPM right now so
for the moment, even though I said initially I'd suggest making broad sweeping
changes to this entire table, let's just focus on our 2000 RPM cell. What we want to do, let's make a
reasonably big change for a start. So if I press the P key, that'll allow us
to enter a percentage change. What we're going to do is start by actually
just adding 50% to that value. So again initially when you're setting
this up, make a reasonably big change. Don't mess around with 2-3%, that's once
you're actually starting to really fine tune things and frankly, you're probably
never going to be in a situation where 2-3% is going to be make or break. So we're at that same point now where
we were, we're under stable conditions, our air/fuel ratio's under control. Now because again I can't pause this little
graph down the bottom, I want you to take note of what happens as I punch
that throttle, we'll do that in three, two, one, now. OK so what we can see there is we've
still got that lean initial spike, again not too worried about that. The engine's still responded quite
crisply and then unlike last time we actually start to move down towards our
target air/fuel ratio. So that's actually probably a step in the
right direction. Now the problem is that there are two
parameters that coincide here. The first is our fuel enrichment
synchronous amount and this also gets affected by our decay time. So in that instance it actually looked
like, to me, it pulled out the additional enrichment just a touch too early. So let's see if we can address that and
get that a little bit better. So we'll go to our main setup and we're
going to go through to our load acceleration deadband, now remember this
is essentially our decay parameter. Again, initially let's make a wholesale
change, let's just halve that value, doesn't matter, we can always come back
and make a change to that later, so we'll apply that change, let's go through
and we'll have one final look at that value there. Now it is also worth mentioning here that
the PC logging for the Haltech Elite is actually at a really low sample rate Off the top of my head, it's only sampling
somewhere between about 2-4 Hz, so it's a nice quick way of getting an idea of
what's going on but it's actually going to mask some of the real data which in order
to analyse that, you're actually going to need to take an ECU log and analyse that
separately. Anyway, we're back to about that same
operating point, let's just again smash that throttle open, again looking for what
happens in our trace. Let's do that in three, two, one. Alright so what we've got there,
we do have a little bit of improvement, again I can't pause it, we see that slight
leak spike, moves rich, probably if anything our decay time could be increased slightly
more but again at this point I am still getting nice crisp response. So the thing that I try and stay away
from is adding more acceleration enrichment than I need. This actually can be problematic and
particularly on multiple stabs of the throttle, if you've got too much fuel going in,
this is where we can really get the car, the engine start to bog down. So I will err on the side of basically adding
as little transient enrichment as I can get away with in order to get control over
my fuelling. Again, using the air/fuel ratio trace as an
input to help guide me with my tuning, but realistically the one that I'm most
worried about is how the engine actually feels, how it responds to that
throttle input. Alright we'll head across now and we'll have
a look at our questions and if you've got any more, please feel free to keep asking
them. Our first question comes from Vikrant,
I think it is, who's asked, how is the fuel load on the x axis of the table calculated? OK so on the volumetric efficiency or fuel
table, that fuel load is simply the manifold pressure. The reason it's called fuel load is that
depending how we've got the ECU set up, we could have that as throttle position
for example. So it's just generically referred to as
fuel load but in this case, manifold pressure. Looks like that is the only question that
we've got. So obviously I've done an outstanding,
stellar job on explaining everything and everyone who has been watching
now has a full understanding of how to correctly dial in their fuelling or their
transient enrichment on their Haltech Elite platform. Doesn't look like we've got any more coming
through so I will end it there but if you do have any questions that crop up after this
webinar has aired then please feel free to ask those questions in the forum and
I'll be happy to answer them there. Thanks for watching and hope to see you
all in our next webinar. Now for those who are watching today on
our YouTube channel, this is just a little insight into what we do every week for our
HPA gold members. We choose a particular topic, we vary those
topics between engine tuning, engine building and wiring and we dive in
deep for around about an hour and if you can watch live, you can ask questions and
get answers in real time. Now HPA gold members get to review these
webinars in our archive where currently we've got over 230 hours of existing webinar
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get access to the webinar archive, they'll also get access to our private member's
only forum which is the best place to get answers to your specific questions. Now if you are interested in gold membership
then that can be purchased on its own for $19 USD a month, however you will get
three months of free access with the purchase of any of our courses. If you want to learn more, check out those
courses at hpacademy.com/courses. Alright thanks team, thanks for watching
and hope to see you again next time, cheers.
