Holley Efi Closed loop and learn functions explained

[Music] hey guys today I'm going to go over kind of closed loop and learn functions in Holley software but I wanted to preface this video about what it's all based off of and that is the oxygen sensor so for display purposes I've got this pin here that's going to simulate our oxygen sensor and the reason I'm making this video the way I am is because I've gotten a lot of messages as of late that people rely upon closed loop to do a lot of their their fuelling adjustments and I don't think that a lot of people understand how it works so I figured I would make this and explain it a little bit so this is a you know we're just gonna this is sitting on a bench here because it's easier for me to show it to you this way well you got a down pipe and we're coming off of the turbo here and we've got this is off of my car and I've got two o2 sensor bungs here okay now they tell you the minute to mount this between 12 and 18 inches after here okay so ideally you'd be 12 to 18 inches after this okay so the reason I have this laid out the way I do is to explain to you why this is here for my car I'm not telling you that this is the way you should do your car but you know this is just for reference so we come on from the turbo you want the o2 sensor after the turbo okay so come over the turbo you got no two sensor bone now my core has two different exhausts for it okay so this one here that you see this one exits out the front bumper okay then I have another one that swaps over right here at this flange and goes out the back of the car so that's why these are the two sensor bungs are the way they are because this is where the only spot I could really put a V ban flange in order to make them swappable so we why I don't have you know bungs down here at the outlet which is you know this is the outside of the car right so this is where the exhaust coming out the reason you don't have a bow to bow like here or here to get that 18-inch number it's because we've got a big five inch straight pipe that is open to atmosphere so what happens is that idle your o2 sensor reads lean because you know to sensor measures oxygen okay it doesn't measure fuel it measures oxygen all right so it reads the amount of oxygen that's going across it not fuel so that's the first thing that a lot of people seem to mistake now if you're measuring oxygen okay at idle right there's not a lot of pressure coming out of this pipe okay so you have oxygen going in okay so we have oxygen going in like that and we have a sensor right here what do you think the sensor is gonna show us the sensor is going to show us lean even though the engine way up in here okay could be very rich we have a false lean here so it seems rather common lately that a lot of people are using closed loop and learn to kind of get the car to run completely and you know and race it off of that but I always suggest to you know get this car to idle and you know low rpm manually and then enable closed loop you know a little higher rpm where you'll have a better feedback from your o2 sensor this car my car has fantastic o2 sensor you know feedback from it that idle and it's partially due to the fact that we've got a good bit of distance and you know some bins before we get out here so the bins slow down air flow right so they say if you can make a pipe twelve inches long off the back of the turbo it'll be better yada yada well the caveat to that is if you make a pipe that's only twelve inches long and it's coming out the top of your bumper your o2 sensor is pretty much useless so it has to meet her it has to meet her oxygen inside of that big freaking hole so if the hole is really big the five inch pipe there's a good chance that's going to pick up a false lean condition at low engine rpm because this isn't spinning very fast and moving a lot of volume so that's the first thing o2 sensor placement now I'm going to we're going to go over the software and look at you know sending up closed loop and learn in the software you know I guess I would say the right way and explain what all the differences are between all the different tables so let's go over to the computer alright so now we have an understanding of what the two sensor does where we should put it now we're going to go over what closed loop and learn actually does so this is our base fuel table right so what first we're going to look at you know these these are all pounds per our numbers but first we're going to look at what a target air fuel table is right so we're in the fuel ICF right up here and we're gonna hit target air fuel so this table right here is basically what we're telling the ECU what we want to target for an air fuel number at X rpm and Y boost pressure or map signal so vacuum weather so we are going to what will do is will populate this table based off of what we want for our target air fuel if you don't have an understanding as to where to start with target air fuel there's there's a there's a hundred one different ways to look at it you know some people tune cars leaner than others depending on the fuel a lot of it has to do or all of it has to do with what type of fuel you're using and also the engine right so every engine is a little different every engine wants a little bit different target air fuel but a lot of this comes from experience in from you know pulling spark plugs and reading them so I'm not gonna get into what numbers to key in here because that will be your decision I'm just gonna explain to you how this works okay so if we are targeting 13:5 air fuel in this area right here okay what that means is if closed loop is enabled what that means is when we are in that same area of the fuel map if the o2 said you know as the cars running this you know two sensors read and say forty know I have but we're targeting thirteen five it's gonna start adding fuel and so we get to that thirteen five all right so if we're targeting thirteen five and we're reading fourteen oh it's going to start to add fuel it's gonna start reaching it up in order to get the o2 sensor to read the target number that it's looking for so now you could probably see why it's rather important to to kind of tune this area of the map manually to get the car to run start idle you know that kind of stuff for sure this is like your first step right so when you're when you're messing around in here you can make your manual adjustments but you're gonna have to disable your closed loop and your learn function before you do because otherwise as you're making adjustments close loop is gonna be in the background telling you to knock it off and you know start coming back to that same target air fuel number so what we do is we go into the system ICF and we go into the closed loop learn right here closed loop slash learn alright now this is a global folder from a car work on and what I do is this is at 4,500 rpm so after you release the transbrake it'll it'll you know allow adjustments in these ranges okay and then the learn parameter is the same so it doesn't matter what's in here for values on this demonstration I'm going to explain to you why it matters for you to do it a certain way so the easiest way to explain that there was between closed loop and learn is closed loop is real-time modification through your base if you have a table okay so if you're familiar with like HP tuners this is short term this is your long term right so fuel trims so learn is when this scene a amount of closed loop addition or subtraction from the fuel table it starts to populate a learn table and these are the limits that were allowing so we'll go box by box do we want to enable closed loop so you can disable this completely on the ECU will not make any adjustments to your fueling in the form of closed loop okay now so we're going to enable that right and then you can enable a minimum coolant temperature for closed loop so the reason you want to do that is because as the car sitting there warming up and idling it could read the air/fuel could be off from what you're actually targeting once the cars you know hop then you have a minimum RPM to enter closed loop so this is this one's pretty important so if you've got a car you know whatever a turbo blower nitrous does really matter if it's got pretty big exhaust on it there's a good chance that you at idle the o2 sensor is gonna read kind of erratically okay so this is this is where you kind of need to focus on that first all right so typically where if it's a bit a well-designed exhaust system you know and everything's sealed up and leak free that's the other thing if you've got one of these V bands that are leaking let's introduce an oxygen you'll have some false readings so I typically like to start at like 2200 rpm to enable closed loop right so we will allow closed loop to make any changes under 2200 rpm so that's a good starting point now if you've got a car that's got full exhaust all the way out the back and it's pretty mild combination the camshaft doesn't have a lot of overlap or something you know you can enable closed loop if you want but this value here is the minimum rpm before the ECU will make any changes to your fueling okay so we go back here the fuel ICF that right here all this from here over it will not do anything here okay so as you're watching the car run live on the laptop and the hold of bubbles bouncing around all over the place right it will not do anything over here if we have a we have a minimum rpm to uh to start closed loop functions okay next you've got a TPS amount before you enter closed loop so if you do wind up putting bar p.m. at close you know at the minimum rpm at close to enter closed loop let's say a thousand rpm right but you don't want to touch your idle all right so it idles great you're real happy with how the thing idols but it idles around nine hundred to a thousand you enter a TPS value minimum before it will enter closed loop okay so it won't sit there and do anything volatile so you can enter this value at if your car drives around town fantastic and you don't want to fool with it you know you can put this at 50 percent right so that means it doesn't matter what RPM you're at if you don't go over 50 percent RPN or a 50 percent TPS then it will not modify your your fuelling then and then there's also the ability to enable TPS to enter open loop open loop is where the ECU makes zero correction based off of what you've keyed into the target or a fuel table okay now these values here this is notice this little plus sign right and then you got a minus sign here right so this is the addition of fuel right so if these parameters early that's been checked these parameters are met right so we're over 50% TPS and we're over a thousand rpm right we are allowing the ECU to add 50% fuel or remove 25% okay so if we go here back in our fuel ICF right and just find oneself here you go 100 miles per hour if you go right there so 1.4 pounds of boost and 3100 rpm okay that means that it will allow it to come all the way down to 50 pounds per hour or go up to 125 pounds per our school okay so pretty simple math but if you put numbers here that are ridiculous like 300% or something it will allow it to triple the fuel volume and then you know typically you'd like to tighten these windows up okay so tighten these windows up to maybe you know ten ten percent or something you this is kind of your you're tuning style what you decide you want to do the closed loop has in over the years you know you read people all the time you see the little memes or people say oh man Holly closed engine yadda yadda typically it's because they've had you know twenty or thirty percent correction allowed in these tables right so if you've got a five percent if you're only allowing the ECU to say at five percent at thirty point 6 psi and fifty 188 rpm and up right if you're only allowing it to be within five percent that means that you're up here all right you got 926 pounds per hour of fuel right so it's going to have five percent of that so you're kind of limiting its ability and that's perfectly fine as long as one keep up with your with your maintenance on the engine right so keep up with your fuel system make sure that you know your injectors don't sit forever in your clogged this isn't as much of a problem on gasoline as it is a problem with ethanol and methanol fuels but uh or even q16 is pretty bad about you know taking a set of injectors and turning it to trash so as long as you stay on top of you know your maintenance on the engine and you feel like you've got the tune-up dialed in very well there's no issue with with knocking these values down to say you know 10% or 5% and then again you could do the same thing here if the removal of fuel okay so this is the addition of fuel this is the removal of fuel so all the same things happen in the learn parameters okay so you enable based fuel learn okay and then you have an RPM that you can enter learn and then a TPS you enter learn same thing values all the same stuff okay what the difference here with learn is it populates a table so here is a learn table where we're adding you know 15 H percent fuel here down in the Cruz area or a very light pull out from a stop sign type of area right and then up here we're removing 15% fuel right so this was probably from a pass that you know didn't have a lot of power in it or something because we're only at like you know one six pounds of baby or something like that and then and then as we increase looking at we got a spot right here this cell is uh it's kind of out of the loop here right so what's the deal with this cell twenty seven point five pounds of boost and 6,400 rpm we go over here and right there that spot right there it wanted some more fuel so if you look it was a little low on fuel so we had seven hundred and fifteen pounds per our fuel 745 so what it did was it right there in that spot the learn table populated a 13.5 percent edition of fuel okay so this this is a sign that says hey we're off by 13 percent here we're off by 10 percent here somewhere around there and then we're we're off by 15% here through the middle of these these numbers here you know 2 3 4 % 5% don't chase your tail but if you're confident in what this learn table has spit out right if you like what it spit out for you you can do a couple things you can you can just hit transfer learn the base and what it'll do is it'll make these do it will make these changes to your base fuel table that you have hot that that's lit up here and it will either remove or add fuel if it is something that you are you say hey you know what I we had a pump going battery at low voltage and this is why I started to add fuel right up here we don't like this we can highlight that area and we just press the zero cage and now we can just transfer this to the base fuel table or a this this area here this whole area here was when we were driving the thing around and around town and then I found that I had a v-band clamp that was that was leaking right so we can highlight that whole area zero there we go but if we're happy with all this stuff here and I'm not telling you to just make these big wholesale changes I'm just showing you how it works if we're if we're happy with this area here right and this is what we want to do we can hit transfer learn to base and it's gonna ask you do you want to smooth the fuel table with the learned values I always say no the reason being is what it'll do is it'll modify a couple cells away depending on how large the value is okay so like if this value subtract 10 percent value was here it's going to subtract fuel from here and all of its surrounding areas ok so I just I said no and come back over here to your base fuel table and you'll notice you'll see these little see those little black dots right so those little black dots are indicating that those cells have been modified and so all these cells were modified because from the the fuel the transfer learned to base table so hopefully that explains the difference between closed loop and learn both of you very helpful tools but understand that you need to get the tune up pretty close you know beforehand before relying upon closed loop and learn to do basically your job for you but I will say out of the I've worked with you know quite a few handful of ECU's over the years and Holly's closed loop correction seems to be about the best on the market as far as following a target but good info in is the only way that you are going to get good results out so if your target or a fuel table has got like ten oh here and it's got like nine five here and it has eighteen oh here right at that it's going to do radical things here in these cells so make sure that it doesn't look like trash when you're you know when you're looking at your turn in air fuel table the heat map is nice because it's kind of is a quick easy way to spot check like hey you know this is red this is purple something's wrong here so hopefully hopefully all understand you know how Turner fuel and how your closed-loop and learn actually works in your ECU so alright guys have a good one [Music]

Channel: devin vanderhoof

Views: 19,388

Rating: 4.9390864 out of 5

Keywords:

Id: CrEwT3a782E

Length: 22min 6sec (1326 seconds)

Published: Fri Nov 29 2019