Boost Control Set Up Part 1 Open Loop

subject is boost control setup part 1 open-loop topics for today will actually review some of the previous webinar that I have conducted on lose control and I would strongly suggest that people watching this webinar have previously watched the helpful hints on boost control plumbing webinar if the boost control Plumbing is not correct and sorted no point in trying to get the computer to do electronic boost control of the engine it will struggle all day long and get nowhere so that really is a must to previously watch the helpful hints on boost control plumbing so we'll go through some of the plumbing diagrams from that webinar we'll talk about some precautions again before we get into putting this engine under any load and briefly talk about that two methods that we have available for controlling boost two main methods I had a little bit of feedback from the last webinar that some people didn't understand the term duty cycle so we'll cover that to a small degree as well today and then I'm going to go through each of the menu items in the boost control setup just so you understand what each setup item means and that way it will help you understand and depending on the method that we use what what to fill in where we'll do some talking about the testing of your setup and some aim table examples the aim table of courses the boost control aim of what you would like the boost to be and then there's some logging results I've got at the end okay so just briefly again from the previous webinar just did some pictures of some basic layouts common layouts of boost control this was the older-style boost control where effectively there was no external intervention now I'm adding or subtracting anything to the boost line and boost is controlled by the spring pressure in the wastegate actuator and then in the early days people put on some manual taps into the boost line effectively wasting air away from this actuator and people rolling in just bear with me I focus on just just started so we're reviewing some of the previous webinars screens so back to the manual control system so effectively we have a spring controlled manual actuator that can be overridden by bleeding ear away so the air pressure doesn't get to the top side of the diaphragm therefore doesn't press the spring down therefore doesn't open the exhaust wastegate boost goes up open the tap more the more air is wasted away out to atmosphere therefore the boost less but it needs more boost in their compressor to achieve enough pressure to open the wastegate actuator not a bad system and particularly if you just want to lift the boost to a cent value it works fine difficult on the fly though if you want different boosts at different times so then the first vehicles arrived with a duty cycle based solenoids and effectively we have a solenoid in line on the bleed and the solenoid pulses on and off to bleed air out the computer controls the width of the pulse or the duty cycle and the amount of on time is off time as the duty cycle so if the valve is on for 50% of the time on for half the time and off for half the time that's called a 50% duty cycle and we'd expect to bleed half the amount of air away that the salt the solenoid is capable of bleeding so if it can flow 10 cubic feet per minute at 50% duty cycle we would hope that it would flow something like 5 cubic feet per minute away from the pressure line going to the waste gate then we got to three-way valve valves controlling boost and this was I'm not sure the reason they are invented but people started using them I just go back actually to explain some of the downfalls when you have a valve system like this bleeding air away from the boost line here the restrict unit require a restrictor if you want to bleed a lot of air away or if you want the boost to go up a long way the reason for that is if the solenoid can only flow and our example was 10 cubic feet per minute away at a hundred percent duty in other words the the valve is open the whole time and there is a capability of 15 cubic feet of air through the lines it might mean that you can't get rid of enough air out of the valve to the atmosphere to lift the boost high enough so the way to help that work better and in fact manufacturers factory install a small restrictor in the line so for instance Mitsubishi and and Subaru both the Evo series and WRX STI series for the Subarus have in line just before the t-junction a small restrictor so in our helpful hints on booster control webinar we talked about reducing the size of that restrictor to help lift the boost higher the duty on the valve is too high so if you have you can have the the whole system plumbed up perfectly and you might get to the point where the boost goes up as you increase the duty cycle but it may only get to a point where the where you're saved three or four pounds short of your aim boost value so for example maybe you're after 18 pound and it up at 50 percent duty cycle you get to 13 pound and at 80 percent duty cycle you get to 16 pound and you go all the way to a hundred percent duty cycle and you only get one more pound boost so the problem is that the the valve is not letting it up here away from the system and so decreasing the size of the restrictor allows more air to be bled away from this part of the of the the hose hoses etc not sure the word for that obviously anyway um tuning the plumbing goes a long way towards helping the computer get the boost control linear and within the range you want so it's quite important it's very much a two-stage deal setting up a good successful boost control system okay so but one of the ways of getting away from the restrictor thing is to use a 3-way valve now this valve if we're still plumbing on a an integral waist grade gate so that's a waste gate that you would see on a factory car where the waste gates part of the the turbo when the valve is off in this case the line between the compressor and the actuator is open and therefore the spring gets compressed and the boost goes down and but when the valve is on the line between the compressor and the actuator is closed as you can see there's no path here and it simply opens and bleeds out the air from the high side of the actuator so what this does without the need of a restrictor allows the duty cycle range of the solenoid to basically increase the boost to any any amount that the system is capable of so it's quite an effective way of doing it the valves I assume the reason manufacturers don't use these valves is they're expensive because I'm sure that maybe manufacturers that do use them but I haven't seen any the majority of manufacturers Japanese etc that um I've seen in use even up to last year's evolution 10 all using a system like this a single solenoid or a single path solenoid so aftermarket wise you can buy these valves motek sell em and there's a number of other valves that are similar that do a similar thing so if you plumb them up in this manner for this type of boost control system they work very well things get more complex when you start to use a remote waste gate so the majority of people running larger boost and aftermarket turbos usually find they have remote waste gates and we recommend the plumbing for those remote waste gates goes in this fashion here we buy you have a line underneath with no velvet going from the compressor to the underside of the diaphragm this line helps to lift the waste gate very quickly when the air is bled away from the high side here to reduce the boost so in this particular case when the valve is on the boost is released or the pressure is released from this side of the diaphragm note the spring is on the other side of the diaphragm in this case so in this case for a remote wastegate with a three-way valve plumbed in this fashion when the valve is on the boost goes down which is the opposite of the previous screen okay but we do talk more detail in more detail about that in the heads on lose control Plumbing webinar anyway so I'm assuming that you have your system plumbed up and that if we effect a change on the boost control solenoid that we should see a change in boost level assuming the plumbing is correct now as with the previous webinar I want to make it very clear that when you're doing this kind of work the situation for an overboost to occur is as quite common you get some of these settings wrong and you could make an enormous amount of boost and advertently and potentially damage the engine so some of the key things that can happen in an overboost situation is that you exceed the pressure of your manifold pressure sensor so in the example here many people use what's called a 3 bar map sensor which measures two bar boustan one bar of vacuum the two bar boost is which is approximately 28 pound but the total absolute pressure measured by the sensor is 300 kPa now in your mouth I'll pressure set up in the input pins you have an option to use a default value if that sensor goes into error now a Center will go into error more often than not when you over boost the or go beyond that senses boost rating so for instance if it's 300 kPa sensor then if you go above 300 kPa you'll had a diagnostic the voltage will probably go above 4.9 and the sensor will go into error now the default number in most of the setups around the basic motek start file of course we know what people are using that for the default number in here is a hundred kPa so if this thing happens to make 320 kPa a boost and you've got a rather excited man on the pedal and he's holding it flat there and that's at that boost level the sensor will go into error and if you don't change this default value when the sensor is an error it will use the existing number which often can be a hundred kPa so the computer then looks up the fuelling for 100 kPa and the engine if it was tuned reasonably well would lean out and potentially hurt itself so we need to prevent that by if we can so we can put in here a default value now you could even make this 330 kPa if you want it so if ever the sensor went into error on a high diagnostic voltage error we the computer will use a substitute value and if it used 330 kPa then that should be a nice safe amount of fuel obviously we can put up some warnings and a few other things but that's the first thing that I want you to check okay the second thing and in the boost control setup so under functions boost control and the first setup page there is a thing called over boost cut now this is a very severe cut and in fact it's a hundred percent fuel cut and what happens is that if the manifold pressure exceeds the value that you put here all injectors are shut off until the manifold pressure falls below so it is a severe cut but it isn't an all-out protection and to allow you to have some indication if you are driving the car writing the scheme driving a boat of knowing that the engine is over boosting by dramatic amount now I would run this say 20 to 30 kPa s kPa above your aim boost so if we had a name boost where you want it to run 220 kPa most of the time then an overboost cut of 250 might be appropriate because the last thing we need in the race is for this to the boost having a little surge a little over spike and we don't need it it touching this overboost cut so just use it wisely but on those first few runs when you're testing your system when any sort of booster could occur it's a good way of just making our safety some big turbos can make astronomical amounts of boost and blow hoses off and cause you all sorts of grief you're trying to get the tuning done so this is a way of just protecting it alright now there are two main methods used by the ECU to control the level of boost um the first method we call open-loop so this is where we sit in the aim boost table a particular duty cycle and that's what's used by the computer so for instance at 6000 rpm we might end up with a number of seventy in our aim boost table and what that means is seventy percent duty so the solenoid is on for 70 percent of the time and off for thirty percent of the time and this will mean a set amount of errors bled through the solenoid and the boost will get to a as measured by you a set number it's not closed-loop it's not an amount of boost that you're asking for not not like 10 psi or 16 psi it's simply a duty a duty of the solenoid so that that's therefore open-loop it doesn't try and achieve a certain boost it simply the computer simply looks up the aim boost table and runs that number whatever it is now this is when you're setting up a boost control system regardless of what you end up with even if you go to a closed-loop system have to start by using an open-loop system and recording all the normal duty cycles that are required to run boost levels different boost levels will require different amounts of duty cycle on the solenoid to achieve them so no matter which method you are using you need to start by using the open loop method the nice thing with the open loop method is that there's no unpredictability and doesn't rely on someone's skill on doing PID control and it does exactly the same thing every time now if the boosters bearing it isn't the computer doing it it'll be something to do with the system so it allows you to dial in your mechanical the mechanical side of your boost control system get that right get data as good as it can be and then you move to a closed-loop system using PID algorithms so but today's webinar is about open loop only and future webinar will be on closed loop that future webinar on closed loop will be following a separate webinar on PID control so you'll need to learn what the terms P I and D mean and have some idea of how they affect a control system alright just a not not the flashiest of drawings but a small small drawing on duty cycle and sometimes it helps to have a drawing and sometimes it doesn't maybe but anyway for that this is a scope trace or a voltage trace of a solenoid in operation a boost control solenoid so if we would have put an oscilloscope or a good multimeter on the wire of the solenoid we would see when the side was off we would see 12 volts and when that ECU turns a solenoid on it grounds it so that then energizes the coils on the solenoid and opens it now if we turn it off again before the coils get fully energized then the shuttle valve inside doesn't quite open the whole way and by varying the amount of on time versus off time we can move the shuttle valve like a needle valve inside the solenoid at different heights of the seat so different distances so by turning it on for a longer period of time we would normally allow the solenoid to flow more here and on some systems flowing more air means boost up and on other systems flying more ear means boost down so it can be quite confusing you need to understand what your system does and what the SOT the duty cycle is doing and by looking at your log data and looking at the setup so if the solenoid is at the computer is grounding the solenoid and the current is flowing that's deemed to be turning it on and so if it's on for a quarter of the time and so on for twenty-five percent or a quarter of the time and off for three-quarters of the time we call that 25 percent duty cycle so the cycle time is the time from the first between each each time it goes to open so at this point where the arrow is it's opening the the first time and over here is the next time it opens so that becomes the cycle time and then simply that if you were to measure the on versus off time that would give you a percentage of a hundred out of a hundred and that would be the juicer now it's useful to understand that most solenoids will do very little at 10 percent either end so from 0 to 10 percent you'll get virtually no air flow and from say ninety to a hundred percent you'll get virtually no more air flow and that very is very much affected by the type of solenoid now I've said I've got one at the moment actually on a jet ski I'd say I think they call it a Mac valve it's a blue one used by other some other ECU manufacturers and it's an extremely coarse solenoid it's got a lot of air flow and at the moment from my lost boost setting to my highest boost setting I only have a number change of 10 so 18 a duty cycle of 18 is the lowest boost I can get and a duty cycle of 28 it's the highest boost I'm prepared to run at this point and I'd suggest probably by 35 or 36 Judy it'll be out of anymore boost it'll be well over sort of full bar so so we need to find out what duty cycle range affects the boost in the area we want to run and so for different valves and different plumbing the numbers will be different so just to understand and to review some of the basic setups and the basic difference between open loop and closed loop as with all the all of the school most of the screens and the motek software if you press f1 and any table you will get an explanation of what's relevant so if you go to functions Boosh control and then terrain boost and get into that table which you see down here and press f1 you get a description of the differences between open loop or simple duty cycle control and closed loop and in that same help screen it will give you the numbers to put in all the tables that are not used during simple duty cycle control it's quite critical to get those numbers correct otherwise you're even the simple duty cycle control will not work you can always review this webinar all right and the other basic setup that you need to do when you're setting up your boost control is part four obviously why the solenoids to the correct output is to allocate the boost control function to the appropriate auxiliary output that you have why the sign too so most solenoids will be wired to 12 volts and the power goes through the solenoid and then to the ECU and then the ECU takes the the power or the ground or the cut the current sorry to ground by pulsing the solenoid so all we need to do is select the boost control function which was obviously our first function we ever did because it's number one and then go to the parameters and you can see them down here and then set their parameters as appropriate now you'll need to go back to the help winds on boost control plumbing for an explanation on the correct parameters alright so again just a quick review normal setup is bigger what we want to add in our aim table I'll just quickly go back so you can see that this is all about changing the aim table our aim boost table and the shortcut for that by the way is f7 on the on the keyboard so if seven should take you to the aim boost table and in this table we want to put a number that represents boost again reviewing an open loop that number will be the duty cycle applied to the solenoid when we're in closed loop that number will be the actual manifold pressure in kPa absolute we're doing a simple open loop today so that this is what we're looking for and if we get our polarities and everything set up right basically bigger number here should mean more boost if you find that you've got a bigger number making less boost then you've got the polarity wrong and the set up so as I said earlier different setups can mean different physical setups can mean judy articles boost up or judy up chemical boots down the polarity fixes that and you can see again also how that changes 30% on one system is 30% on and 30% and on another setting means 30% off if you're not confused now just wait alright anyway ah so testing we need to add or subtract judy by adding and subtracting numbers in this table we need to be take here and if the boosters low we we should lock the gate and find out why we'll get to that surely it's still a review from our last webinar but in there alright so menu items so I'm going to go through each item now and give a quick explanation of what what I have what happens in each screen so the setup we covered earlier the basic setup which will serve the type of control and the overboost cut the main table that you'll spend your time in is the aim boost table alright so this is the table where you put in the number that changes what the computer does so in open loop mode this number is the duty cycle of the solenoid so in the example you see here a hundred means basically that valve is on the whole time so it should be flying the maximum amount of air possible through the valve in closed loop we would be putting in here our aim booster actual aim boost that we want to run another and the computer using PID tries to maintain that now yeah if it's not tuned right it won't so I open loop whatever numbers here is what goes on the side right the next number down is the normal position table so in open loop mode that's not used all right and then when you read the help in the aim boost table pressing f1 we'll tell you to make sure this table is zero I've just given you a little example of what you might expect to see if it was closed-loop effectively the normal position is the position the the solenoid duty that we would expect to maintain a certain boost level at a certain under certain conditions so for instance at three and a half thousand at 200 kPa if we line up the number we've done all our R&D properly we expect the solenoid duty to be approximately 55 percent so when we're in closed loop mode we fill this table out and I'll speak a little bit more about that later right the next one the trim this is a very simple trim exactly like the overall fuel trim and the overall ignition trim so this is simply a plus/minus percent of the aim table and again if you press f1 it will tell you effectively that so it's simply a percentage of the aim boost table whatever numbers in the aim boost table this will add or subtract that this percent of that number next line is air temp and compensation now perhaps you don't need to worry about this under initial tuning but once you get this setup done it's quite useful to remove boost if there's any problem with the air temperature so if you look in the table at this example you'll see that at sixty degrees Celsius we're removing 20% boost and if the air temp gets to be eighty degrees Celsius we're removing a hundred percent of the boost that still means it'll run whatever the spring on the wastegate is but at least we've got it down to some sort of manageable boost level the fact is that an air temperature is determined by the tuner at eighty degrees is rather hot if 80 degrees is normal well you have zeros there but in a good race engine I'd expect to be trying to keep area temps under 50 degrees Celsius just a small note here that all tables in motek software virtually all tables interpolate so what that means is anywhere where there is not an actual number here and a corresponding number underneath the ECU interpolates the two so if we go exactly between 40 and 60 we get a number of 50 so if the air temperature is 50 degrees Celsius what would you expect the boost compensation division minus 10 it's an exact linear interpolation so at 45 degrees Celsius that would be minus 5 so don't assume because you see a zero at 40 degrees air 10 and I minus 20 at 60 that at 59 degrees air temp you'll have no boost reduction while you will so the moment it goes past 40 on its way to 60 the boosters start dropping okay engine temp same thing this example here shows some that the tuner is wanting to be kind to the engine so he won't let the boost go above above the gate value or the spring value in the wastegate until the engine temperatures at least above 45 degrees Celsius and you don't get full boost until it's above 50 just be aware that if this is a boat and if it's got an open water system maybe through just a little bit much water going through the engine the thing might only run 45 degrees Celsius someone's open the tap too much and you're looking for why you've got no boost you'll need to come here and have a look and make some changes all right and similarly up the top when the engines starting to get hot we can remove boost as well okay we've got also a couple of generic compensations so what that we get view a the first one is a 3d table and the second one is a 2d table so it's effectively three separate sensors that you can use influence the boost now I've got our full throttle timer configured on my first compensation table again it's a very simple plus/minus percentage so whatever the number is in here it's just a percentage of the aim boost and I use full throttle timers for testing initially when testing jet skis because you can't be it's difficult at least to take your laptop in the jet ski at 70 something miles an hour and start playing with duty cycle numbers to see if the boost goes up or down so a way of checking the response and off the boost control system especially when running closed loop is to start a timer at full throttle so I can run along at 95% rata land the engine settled at full boost or near enough to it and if I squeeze the throttle all the way to a hundred the timer goes off and then after in this case one and a half seconds I pull 10% out and then after two and a half seconds at 20% and this happens automatically now I can download the logging and have a look and see for how the boost control is responding to those requests I don't have to worry about doing it on the laptop the computer just does it similarly if you might find that you use a full throttle timer to reduce boost after say 10 seconds or 20 seconds of full throttle so if you need to get off the line and beat your competition to the first marker or what for whatever reason most engines will be able to stand a little bit more boost for the first short amount of time until the temperatures get high so this allows you to add that boost and then subtract it away for the rest of the race and then the next compensation and again it's just a generic compensation we can put any table on here in this example I have a channel called boost control komp2 and this is configured to a nine position switch on the chin up that i've got here and was an off-road vehicle where the customer has nine levels of boost and he can simply dial a boost in that he wants for the particular situation he's in and this particular customer does what's called prologues where is a very short race to get the seating for the main race so he dials it up maybe to position seven or eight or wherever he wants the extra boost to be and then for the main race he might leave the first part of the race on position five forty percent more boost in this example and if he's doing well he can just dial it back and just dial the boost back and not have to worry about what conserving the engine and not not have to worry about taking his foot off the accelerator to conserve the engine you can just dial back the boost runs this boost he can still just hold it flat and doesn't have to worry about it it's a way of quickly adjusting what the computer does without having a laptop or anything like that okay the next three terms are the terms that we use for closed-loop control I will very very briefly go over them so you can start to get used to what they are they're not easy to understand and as I say we will do a dedicated webinar on them now you only use these terms when doing closed-loop control the only time you have a number other than zero and here is for the proportional gain and and say it in each of these screens I'll tell you what numbers to put in for the open-loop setup so with open-loop setup we have a number of one in here and that's there's no cheating that's what it is in closed-loop we start with around point three but this number could end up being anything this is effectively the main effort or it's a gain factor that the computer uses to try and reach the aim boost when in a closed loop so if you aim boosters 200 kPa and the engine is currently 150 kPa the computer needs to add more duty to the solenoid and this number multiplies the amount of duty required by the error so if the error is 30 it's 30 percent away we multiply 30 times 0.3 which is approximately 10 so the computer automatically adds 10 percent duty to the solenoid to try and get the boost right basically the larger the number here the quicker or the more the greater the step the solenoid takes to try and fix the error closed loop control is all about fixing errors so the problem with too big a number is that at 10 that the tendency is that the tholly will overshoot so if the actual amount of duty required to achieve 200 kPa is 50 and the current Duty might be 20 and you put two bigger pea number in there the Scion might go to 90 and so what happens is too much air flows the boost goes too high and then the duty on the solenoid has to go the other way and you get a hunting effect up down up down in the boosters out of control so the proportional gain is kind of the main multiplier of the duty cycle to get the boost as close as possible immediately as possible not explaining that very well but anyway the integral gain is again it's a multiplication factor of it it is to do with time the longer there is an error the more this this number keeps adding or subtracting or multiplying to the to the algorithm to add and subtract duty cycle to get the boost correct now in open loop we set this to zero and that's the end of it and close loop we've got to play with this number to get the fine the fine tuning of getting the boost just exactly where you want it but basically it's a number that's used in conjunction with amount of time there era exists the derivative gain again is a multiplier for open-loop control you set it to zero or closed-loop you start with this 0.05 this is kind of like the brakes the brakes on a car and Mark's gonna probably do the PID control webinar and he'll talk about a go to whoa car and similarity of what that's like a go to a race car and how that's similar to PID and effectively this this puts the brakes on a large duty control if it sees the error diminishing very quickly and sees that we need to slow the Duty down to prevent an overboost situation occurring this affects how much the brakes work it's a very basic explanation all right away from that now back to some basics this is the minimum duty cycle in this table here we can simply clamp the minimum amount of duty that the solenoid will use no matter what the PID calculates the we can clamp the minimum to a set figure and that's then what this does is it stops a lot of boost oscillation so if if at a particular let's say 200 kPa in the example here and five thousand rpm if we log an engine for two or three races and we find that under no circumstance did it even need any less than 35 kPa to make China kPa a boost sorry 35 percent duty to make 200 kPa that's not a boost that's our actual absolute pressure so that's 14 pound boost then we have the minimum duty cycle can be set there so we would always wanted a little bit lower if we needed the boost to be lower so by working out over time what the actual normal numbers are we can put a clamp on them smallest number the computer gets to use and a clamp on the maximum number now of course or open-loop control just put the zero alright maximum Duty the opposite adjust of what I said obviously we can put clamps on the maximum amount of Duty used and this is the definitely the one you concentrate on because overboost is is the one we want to try and minimize for the health of the engine and sometimes for rules we don't want boost going over certain amount so again if we log and an example at 5,000 revs at 250 kPa we've logged that we have never ever needed to use any more than 65% duty to get that boost at that rpm well we can safely clamp that at 68 so even if the when we're in closed-loop control even if this the algorithm calculates that it wants say 80 the computer will stop it 68 and prevent that overboost occur now this these two figures here are to do with the integral figure because the integral figure is is to do with the tights to do with time and the time that the error occurs you get integral the integral calculation can wind up its call integral winder so that integral wind-up can cause the duty to get larger and larger and larger and larger and if there's an error that the computer can't fix the integral number or multiplier keeps adding up so these two figures the positive and negative clamps allow us to stop the duty cycle request winding up too far again we'll the next webinar or the PID webinar we'll go in into these in more detail alright so that believe it or not as a basic overview of the setup for your boost control now prior to testing now that you've got some table numbers filled out we want to go through some checks you really shouldn't be attempt a tempting to do proper booze control without having the data logging upgrade you shouldn't be attempting to do anything without the data logging so we always want to look at our logging and we need to make sure that after we've done our first test and opened i2 to look at the data that we've actually logged the duty cycle of the boost control solenoid so make sure you go and log that and the example I think we use today was either auxilary three or four so we need to make sure we've got those that channel logged the other thing I want you to do is make sure that you've got safe ignition numbers at those higher boost values so if you see this ignition table here normally allow 2 to 3 degrees for every 20 kPa the boost goes up so if we happen to have the it might have 14 pound springs and our wastegate and we've tuned all the way to 14 pound and we in this example maybe we've got 20 degrees of ignition at seven and a half thousand revs so we would want at least two to two and a half degrees of ignition out for every 20 kPa that the boost goes up and if you're sort of learning at this you'd almost make that three degrees and this is engine dependant fuel dependent and a lot of lot of things but as a rule that's kind of the ballpark of the amount of ignition that comes out per the amount of boost that goes in okay by all means be more conservative of that than that if you like but definitely make sure that when if you're doing boost control that in the areas where the boost could lift way up because the control is not right we don't need lots of timing in there otherwise the detonation will occur and you could have broken Pistons all right and similarly we want to make sure the fueling is safe there so if again if this is a picture of the fuel map if we have a point that we've tuned 200 kpa and seven and a half thousand red they're fueling as safe at that point let's make sure that all the numbers above there are the same or higher if it's got a rising rate fuel pressure regulator that may not be as much increase in map height here but certainly we need numbers going up it doesn't matter if it goes really rich if the boost goes high but the last thing we need is not smaller numbers at higher pressure so it'll mean that you're going to have problems with definition again potentially all right so are over booze cut thinning just review that and the default manifold pressure setting that we spoke about earlier as well I'll be very careful playing with ignition and boost are the two things that can cause you grief and engine parts to expire alright so testing start with small tests on I call it having a bit of a look now you could be on an engine dyno a chassis dyno you could be on the water you could be on the track what you need to do is is get some small request numbers in that boost aim table so start right down at 20 or even 10 and simply put your foot foot down and just quickly come up into the revs until you feel the boost coming on if you've got a boost gauge or a dash have a look just have a quick look and make sure nothing's getting out of control if you give it a you know a boot full and you get this big cut happening that means you've hit the boost limit and you've got you've got problems so don't move anymore like don't don't don't do any more testing come in and suss out why you got so much boost drop the number right down to zero and go out and try it again if you still got problems still massive amounts of boost maybe you've got the polarity wrong you could try the number the duty number at a hundred again very carefully and if all of a sudden with a duty number at a hundred you're sitting at your waistt gate spring pressure of 12 pound then you've got the polarity wrong now you can still you can tune where a hundred million low boost and low numbers mean I boost that's up to you but need to get a feel for what numbers in the aim table make what boost so if for instance I'm on the engine dyno it's a nice good controlled environment and I will now the throttle and we might be sitting at our nice safe if your ratio right on the gate pressure might be 10 pound I'll get set up have someone watch the engine and then I'll just start typing I'll go 20 enter 40 into 60 enter now if the boost doesn't do anything dramatic during that test or it might just climb small amounts I can stop download the logging and then have a look and see what Judy made what boost and it's somewhere along the line maybe 40 maybe 50 you'll find the boost really starts to climb because 20 is usually a big step so you might find it as soon as it went over it didn't do much until it got to 40 and only did a little bit of 40 but at 60 it made a whole heap then go back and do the test start at 40 and then maybe go up and fives or even twos and just need you to log and record what Duty made what boost if you're on the road or on the water what you keep basically you proceed with a bit more caution just enter 20 and the whole table go and have a test come back orbital logging try doubling at 40 go back do your test and again if you haven't made your maximum boost yet keep adding numbers as soon as you get to a number with a boo starts to climb then only small numbers after that so you the aim is to find what judy makes what boost this is this is the main task alright so eventually if you if you if you've been careful you should have an engine in one piece and some numbers written down that represent boost levels so we find a level of numbers that suit all those boost level what we do is we put those numbers in the aim table and then we can go and run the engine for some longer periods of time maybe it's in a car and you can go out and do a couple of laps at the track and try experimenting with different numbers have a look at the data logging after your test and have a look and see for certain floral positions rpms you'll have certain duties making certain amount of boost so callate all that information and then use it to fill out your boost control main table so as I said here it's likely that will be different numbers for the same boost in rpm and that the boost will be affected by the maybe the time extent held at full swaddle maybe the position of the throttle there's all sorts of things that can affect boost alright but once the numbers have been found we can then structure that aim boost table so here's three examples of three different aim tables on the first one here we've got rpm across the top and it's 3d with throttle position on the vertical axis on the y-axis now what this allows the tuner to do is kind of give the boost of the engine a more naturally aspirated feel so as the customer or the driver is at 50% throttle he's only got maybe 50% of the boost available as he goes to full throttle he gets the full amount of boost that he's after and often you'll find that depending on the compressor map of the turbo even if you were to run say an exact 20 pound boost across all the RPM often you'll need to run more duty as the RPM goes up to try and maintain a set boost level now that that's not what you may want to do but effectively change the numbers to change the boost where you want it changing the numbers proportional to a second sensor like the throttle position allows you to increase boost based on throttle position here's a very simple 2d aim boost table this one's more suited to potentially drag racing so here we have a ground speed channel which is coming from will speed sensor and the customer might find that he's got too much boost on the line normally he uses anti leg to to label on the line and but he can't run the full boost until the car is progressing down the track and he's got some traction so we find in the example here at 10 maybe 10 mile an hour 10 kilometers an hour whatever is configured we're running in table number of 56 which might be say 15 pound boost and then as the car goes faster we can get ramping more boost so we get the boost coming in to the limit of the tire or the track and this way we don't have problems with wheel speeding or loss of traction another simple table and all of these of course are open loop duty numbers a third example here is one where the we have a boost control channel which has been created can be created a number of ways this one was created off one of our dashes where the customer can dial a number in on the dash using a switch or a button customer dials are the big Center number on one of our dashes up just keeps pushing the UP button and as that number goes from 1 to 2 to 3 to 4 to 5 on the dash in front of them we add duty so simply adding extra duty for each time the number goes up on the dash and that information is sent back to the ECU on the canvas and then put on as an axis on the aim boost table so basically similar to the earlier example with a switch you can effectively dial up whatever boost level you want and often that's more appropriate than wanting to aim for a set value it's more the customer can control the boost that he feels is necessary at the on okay a couple of results some screen captures from Aitu from some logging I'd expect that you would set your page out like this when you're looking for what boost is being made by the duty you know what duty cycle is making what boost so I know I - someone coming in on our I to page here the key things that we're after initially anyway is our PM throttle position manifold pressure and the duty cycle of the boost control solenoid so in this example auxilary for duty cycle is what we've logged so if we have a look here we can see that customer is flat through the section so flat out and the RPM this is actually a PwC some PwC logging so effectively the RPM at our data point here is seven thousand three hundred customers been flat the whole time and the duty cycle at this point is 38 now the weather it's a wide-open throttle timer or a switch the duty cycle is increased you can see the duty cycle goes up if we were live in the software we could click it where the arrow is and see what their number is but it's approximately 70 we can see the manifold pressure going up and we can also see the RPM climb from the extra power so in this particular setup we can see immediately that we have a range of boost which is just under half a bus at 44 kPa a boost at 12 pound or something 13 pound at 38% Judy made 13 pound and if this is going to about 65 or something here we can see the boost has gone up to a little bit over one baraboo so maybe we went from 13 to 18 power so that's the kind of result we want and then we can take those numbers and put them in the aim duty table there's another example this is definitely one where I used a full throttle timer to vary the duty on the solenoid now it was I needed to hold it longer because the boost takes a while to build so it was I wasn't the time I was programmed to change too quickly but you can see at the point that I went flat in this particular case the duty cycle again to look he is 70% judy it went - you can see the RPM went well up here over 8,000 flat the whole time of this test part for this little lift here obviously so then we drop the the computer drop the duty cycle down here and it was a value of 30 you can see the RPM went down we can see the boost went down to write on the wastegate in fact very low amount of boost and 30 kPa then the computer stepped up the Duty again went back up to 70 and you can see the boost climb and doing this on and off when you're doing closed loop tuning allows you to see how well the boost responds to a given duty change so we'll be doing that in our closed-loop webinar all right that concludes a rather large and extensive webinar on boost control that's only half of it we didn't have too many of you nodding off and as I say before watching this one it's useful to also watch the helpful hints on boost control and coming up with part two of boost control setup will be the closed loop r1 now I noticed a couple people coming in late on this webinar the webinar will be up online within hopefully an hour and you'll be able to view it then and obviously that can be found on our website at moti comm hope everyone's enjoyed it and we'll catch you next time

Channel: MoTeC Global

Views: 11,293

Keywords: Boost, Control, Set, Up, Part, 1, Open, Loop

Id: l6qSFw7L7jk

Length: 59min 29sec (3569 seconds)

Published: Tue Jun 26 2012