🛠 Boost Control: How to map your boost against gear | TECHNICALLY SPEAKING

hi guys and welcome to another  episode of technically speaking   it's good to be back and it's even better to  be back in the seat of an evo 9 what a car today we're talking about boost control more  specifically boost by gear so basically what's   going to be happening we've got our evo 9 test  mule here this one's actually davos car it was   the mighty car mods car it's a perfect test meal  for this because it's got a really reliable 4g63   evo 9 engine with the mybeck so the variable inlet  cam control got really nice turbocharger on it   it makes about 280 kilowatts of the wheels but  it can also make 220 kilowatts of the wheels   when we're on wastegate pressure so it runs  somewhere between about 18 and 24 pounds of boost   but what we want to talk about today is  being able to configure it to have different   boost levels in each gear so what we're going to  do is first configure our target boost pressure   configuration in the software and what's going to  happen is as i drop to say fourth gear for example   the engine management system is going  to see that i'm in fourth gear it's   going to see that i'm at say 50 or 60 or 70  throttle and it's going to look up our boost   target and say okay i know that he only wants 18  pounds there but when he goes to full throttle   he's gonna want 24 pounds for example one of the  things that we can't do on the dyno is set it up   and do full power runs in first gear  and second gear and probably third gear   on the full drive chassis dyno because of the  torque multiplication of the gearing if we try   and do a first gear full throttle run on a chassis  dyno it's not going to end very well we're going   to end up lurching off the front we'd need a  million straps and it would all be too hard   so i'm just sort of getting a bit of a feel for it  now we'll go back to the shop we'll get it on the   dyno we'll configure the closed loop boost control  strategy then we'll figure out how we're going to   target the boost pressure versus whatever we've  got throttle position versus engine rpm versus   gear even versus this little intercooler water  sprayer button here so i could turn that little   button on and i could get all the beams or flick  it off and we'll go back to wastegate pressure but i am going to have to do plenty  of test driving in this car it's um   evo 9 was my first sort of real first new car i  bought at evo 9 brand new and i absolutely love   it i regret selling it what a beautiful car the  noise of it let's see if it's got the beans too ah what a car now there's a whole bunch of different ways you  might want to manipulate your boost pressure   you might want to have a target boost pressure  versus engine rpm you might want to have it   versus road speed or length of your drag race  you might want to have it if it's a circuit car   your manifold pressure or your target boost  pressure might be versus throttle position   because mid corner at 40 or 50 throttle you don't  want full boost then as soon as the car starts   to straighten up and you start to come out of  that corner you mash the pedal you then go to   your high boost your flat out boost pressure  and it makes the car a lot more controllable   you might want to do something like have a high  low boost switch in this car really good example   it's got an intercooler water sprayer off the  front of it which is factory on this evo 9.   it's got an automatic button you press that little  light comes up on the dash telling you that the   intercooler water sprayer is working well not  so much about the integral water spray what's   important about that is that input goes into the  engine management system that's a channel that's   in there that tells us whether the water spray is  on or off we can use that channel to map the boost   pressure against that so the driver of the car  if the water spray is not on we might target say   20 pounds of boost pressure if the water sprayer  is on we might target 24 pounds of boost pressure   if you're not lucky enough to have a built-in  switch like that in whatever car you've got   you might be able to use like a rotary trim  knob so you could have a 12 position switch   that you'd mount somewhere on the dash you could  have position one as the lowest boost pressure or   the wastegate pressure you might crank it up to 11  or 12 and that's kill mode that's that's as much   boost as the engine is going to take maybe even a  little bit more so the first thing we're going to   do is tell the engine management system what gear  we're in so some gearboxes have got a position   sensor for each gear or a potentiometer that  changes voltage depending on what gear it's got   some automatic transmissions are can based  and they send the gear detection system or   the gear detection strategy via can to the engine  management system evo9 the last of the old-school   mechanical cool evos in my opinion hasn't got  any fancy stuff like that so we need to use a   gear ratio detection in order for the engine  management system to know what gear we're in   it's pretty straightforward all we do is cruise  the car in first gear we go to our gear ratios   tab on the left hand side here then we come  up to this button here what's going on here   i've already configured this but what's  happening here is that 9.1 is what we   detect as our gear ratio for first gear so that  means that we're going 9.1 kilometers per hour   per 1000 rpm so if the clutch is is out and  we're truly engaged in first gear the engine   management system will know that we're in  first gear because that relationship between   engine rpm and road speed only changes when we  change gears the first thing that we'll need   to do the boost control target pressure this  is where we're going to make the decisions on   how the boost control target works so at the  moment you can see that this car is configured   so that if the boost control if the intercooler  water spray is turned off it targets 18 pounds of   boost pressure if the intercooler water spray is  turned on it targets 23 pounds of boost pressure   it's also mapped the second table axis versus  engine rpm so at no matter what the engine rpm   it's always targeting the same boost pressure  in this case so i can change that straight away   all i'm going to do is press f3 or go to the  setup table options and i'm going to change   this around a little bit so i'm going to set  it up so that we've got engine rpm on one axis i'll set it up so it's got throttle position on  the other axes being an evo it's nice to have   a bit less power when we're at light throttle and then you'll notice that i did lose my inner  cooler water spray set up down the bottom there   so i'm going to enable down here we could map it  versus fuel composition so that's a very common   thing so say if the thing was running on petrol it  might run a lower boost pressure if it's running   on e30 we might add a little bit of boost to it  e50 a bit more once it's on e85 we'll run as much   boost as we possibly can in this case i'm going  to change this to inter cooler auto input state and we're going to either select it as a one or a or an on or and off if i press ok what we'll see down the bottom  here in the software all of a sudden that little   bar has turned up down the bottom so if the  inner cooler spray is turned on or turned off   i'm pressing the button at the moment and we can  see the little indicator down the bottom it's on   little blue arrow over here saying it's looking  at this map off looking at this map over here   if i pull that little scrolling bar across  what we better do so if it's if the intercooler   water sprayer is off let's put it at say 18  pounds if it's on let's put it at 23 pounds   that makes it nice and easy and we can flick  back and forward and see how that's working so this car has already been  tuned remembering this was one   of the mighty car mods cars that got  done a couple of years ago since then   davo bought the car he loved it that  much he's been daily driving it it makes   about 280 285 kilowatts at the wheels and  everything's been going really really well   we're using it for the demonstration here because  the boost control sort of configuration and setup   on this car works really well for an example  where we can increase the boost two psi at   a time and see what that result is this car's  got an 18 pound wastegate spring meaning that   with no electronic intervention it's going  to run 18 pounds of boost pressure so   for the examples today we'll go up here we might  target say up to about 24 pounds of boost pressure   but like i said before at lower rpm and lower  throttle positions we might not want to run   as much boost pressure in order to make it  drive a little bit nicer and be a little bit   more controllable mid corner so i might go here  and run 18 pounds of wastegate pressure up to say   or up 18 pounds of boost pressure i should say up  to 40 throttle then i'll go across here i'm going   to go l for linearize to smooth that across and  down low in the rev range as well just to not give   it such a hard time we might go l for linearize  and end up with a boost map something like that   you can choose all different ways to do it if it's  a street car and you want unlimited power all the   time just put one target number remembering  the whole purpose here you can map it against   anything you want engine protection wise  if the car goes into engine protection   we can also change the target boost pressure so  that if it's a light engine protection warning   so something that's not critical and that's  not going to turn the engine off to save it   we could choose to say pull half or as  much boost pressure out of it as we can   and we could also set a boost limit based on  that engine protection we did gloss over a   bit of this stuff in the r35 boost control video  i'll go through this in a little bit more detail   in this particular video because it's all well  and good to tell you yep you type in the boost   pressure and it achieves it and that's as simple  as that but it is a little bit more complicated   like everything in cars it's always going to be a  bit more complicated this is a closed loop system   and what that means is that the engine management  system is looking at the manifold pressure   it's looking at the target then it's doing a whole  bunch of magic in between in order to pulse that   solenoid more or less bleed a bunch of air off  that solenoid in order to achieve the target   and how it does that well it's pretty impressive  but it does need a little bit of input from the   tuner to help it get there the more input the  tuner gives it the more accurate the boost control   is going to be starting from the top the closed  loop base duty cycle if i have a look across here   these have got my target boost pressures so  that top axis is based on my closed loop target   pressure if i was targeting 20 psi of boost  pressure at 2000 rpm before we go into any   closed loop or any strategic boost control  strategy the engine management system is simply   going to start pulsing that solenoid at 19 duty  cycle it's going to do that before it even comes   on boost before anything happens it's just going  to things that's a start position i'll start there   it's going to keep pulsing that at that duty  cycle for two and a half seconds our delay   or if we're at 4000 rpm for example it'd be  at one and a half seconds once that delay   finishes the engine management system is  then going to look at the target pressure   versus the actual pressure and  it's going to drop into its closed   loop strategy using our p id our proportional  our integral and our derivative controller   now this is a pretty complicated topic i'll do my  best to sort of explain it in a couple of words we   will do a future video on pid control stuff with  a few more examples to show you how sort of things   are working in any of the closed loop strategies  whether they're boost control idle control   o2 control so anything that's got an  actual pressure and a target pressure   it's using a closed loop system and it's using  a pid controller in order to achieve that target   once we've got our target of let's say 20 psi we  already know that we said oh well guess about 19   will get us to that target let's say that  19 only achieved 19 psi not 20 pounds   that's where our proportional gain comes in it's  going to look at the actual boost pressure it's   going to look at the target boost pressure well  we're out by one psi in this example of 19 to 20   because of the number i've put in here 0.69 that  means that the proportional portion of the closed   loop strategy is going to increase our output  duty cycle by 0.69 per psi of error so i'm out by   one psi it's going to add 0.7 close enough  0.7 of a percent of duty cycle to our output   for that one psi that should bring it up once we  get up and we have no more error the proportional   part disappears but then we would fall back down  right and we would be back down at 19 psi because   we've got an error again that's where  the second part of the formula comes in   the integral controller what happens here is that  once our proportional comes up and gets us to the   target proportional is based on the target error  if there's no target error there's no proportional   think of that sort of the proportional like what's  happening right now the integral controller's   job is to sort of look at the history of what's  been going on so if we required more duty cycle   in order to meet our target the proportional is  there to say okay and just keep a rolling tally of   what's going on it's also in output duty cycle per  psi of target error but when we meet the target   the integral has already kept a running tally of  what's going on it's sitting in the background   there and it just adds that one percent and it  just keeps that one percent so we stay on target then we've got a derivative gain typically not  used as much as the proportional and the integral   part of the pid strategy the derivative think of  it like we're sort of future proofing what's going   on if the manifold pressure is rising at such a  rate that we know that it's going to overshoot   the target by a mile simply by looking at for  example if we're trying to achieve 19 pounds   of boost pressure and the manifold pressure is  accelerating at 10 pounds per second for example   the controller can look at that and say hang on  that makes no sense because in not much time at   all it's going to accelerate straight past the  target that's way too aggressive that's where   the derivative controller will step in it'll  pull some duty cycle out of the system in order   to get us to not overshoot the target so that's  proportional integral and derivative proportional   what's going on right now integral sort of  looking at the history of what's been happening   and the derivative looking into the future to  make sure that we're not getting too carried away   this is a huge topic there's a million  different ways to explain this i'm going   to think of a better way to explain this on the  bench maybe with some balancing beams or some   remote control helicopters or something like that  but if that gives us a really basic idea of sort   of what's going on in that area and at least  gives us some units to look at so that we know   when we're typing in a number of one or two  or three in the nsp software we get an idea   of what's going on and what the system's doing but  remembering in life we don't want to keep making   the same error over and over and over again makes  no sense same in your engine management system so   if we had set our base duty cycle correctly for  every temperature situation every engine situation   we wouldn't need any closed loop stuff because  you'd ask for the target it'd go to that base duty   cycle and it'd just work but engines are difficult  life's difficult the duty cycle does change on   temperatures on operating conditions and that's  why we've got that closed loop strategy there   so you can get it in the ballpark with your base  duty cycle table then the closed loop will come   and fix up any little mistakes if the closed leap  keeps picking up the same mistake over and over   again we've got this next value here the long  term trim table so if we look over here at our   long term trim tables we've got a bunch of stuff  we've got to enter first of all we need to be over   80 throttle position in order to start the  learning that's because at light loads and   part throttle on boost we're not going to get a  consistent result because there's a restriction   in the engine bank the throttle blade that's  continuously changing that manifold pressure   we want to be above two and a half thousand  rpm because under two and a half thousand   rpm it's probably too laggy to actually come  on boost and make that full boost so we would   end up the controller would just keep learning  and learning and learning but could never actually   achieve it we've got a maximum rpm in this car  i'm going to change that to 10 000 something   we're never going to get to and i just want  it to keep learning as much as it possibly can the minimum gear we have to be in third gear  or above in first and second gear because of   the ratios because it's so aggressive down  there we don't we've got such a high engine   rpm and manifold pressure rate of acceleration  that any learning there's probably going to be   null and void then down the bottom here we've got  a couple of buttons we could either reset it so   we'll just clear all of the learned data and apply  to base table i'll come back to that in a second we've got our long term trim gain so this is  a number that basically is asking us about how   aggressively do you want this thing to learn at  light boot low boost pressures and when we've   got uh not very much target error we don't want it  to learn very much if we're a long way away from   the target we want it to learn very aggressively  so i'll change this to numbers of maybe 5 or 10   when we're pretty close to the target and 50 or  100 when we're a long way away from the target the long term trim table this is the  one that fills in and tells us how far   out our base duty cycle was so if we were out  i'm just going to say along here say our target   of say 19 pounds the closed loop strategy might  decide okay it actually needs two percent extra   there and it might need six  percent or five percent extra there   and for example that might be some learned  data that it would pick up something like that   the engine management system will look at those  numbers it will add them to the output from the   base duty cycle table and that will be the result  that goes to the boost control solenoid remember   before how i said that i would come back to the  apply button well if i press the apply button   here it's going to take all of those learned  values it's going to put them into our base table   then it'll put the learned values back to zero  so you can tune the car you can send it out on   the street it can do a couple of days couple of  weeks months years whatever when the car comes   back we can actually use this as historical data  as well because we could look at this and say   oh okay well it needed to add a bunch of duty  cycle there either i was having a bit of a lazy   day and kind of near enough's good enough which is  obviously never the case right or maybe the things   lost efficiency maybe something's going on where  we need a hell of a lot more effort into that   boost control in order to achieve the same target  boost pressure so have we got a wastegate problem   have we got a boost leak have we got something  else going on so you can look at this and see   historical data it's really useful for that as  well as maintaining our target boost pressure all   right before we go and give this thing a power  and we'll do a couple of different power runs   at a couple of different boost pressures i just  noticed that this video is called boost by gear   when i was setting up the target boost  pressure table you're probably confused because   i set it up versus throttle position engine rpm  and whether the intercooler switch is on or off   so i'm just going to quickly flick down to  rpm and i'm going to change that to gear   that's our calculated gear i'm going to delete  out all those crazy numbers and i'm going to go   first gear second gear third fourth  fifth being at evo nine it's a six speed   okay done okay so there we go so now in my table  here i've got gear versus throttle position   versus whether the intercooler water  sprayer is turned on or turned off so and there's the manual sprayer right there so  everything's working what i better do i'll do   a base run with 18 pounds of boost pressure as  the target so we get a baseline so we can watch   the duty cycle output and see what's going  on i'm going to come down here to the data   logging section of the elite series ecu and i'm  going to add all of our boost control channels   so that i can do some onboard data logging  to the ecu i'll give it a pull then come back   pull the data out and see what's going  on within the software here we've got   three sets of channels we've got 20 40  we've got 60 channels that we can data log   all at different sample rates anywhere between  once every 10 seconds to once every 5 milliseconds i've also got it configured so that the onboard  data logger is going to turn on when we go over   three pounds of boost pressure and then when it  comes back under three pounds of boost pressure   it's going to keep logging for one second and then  turn off one of the beauties about this software   package is that the engine management system all  the elite platform now do the loop data logging   meaning that there's eight megabytes of  on-board memory on the elite 2500 series ecu   that's what this car's got in it that means  that it's always going to be logging we're   always going to have the last eight megabytes  of data once that at eight megabytes fills up   it's gonna start overriding the old  data so we've always got the last   eight megabytes right so that's all the theory  out of the way now it's time to give the thing   a few pulls and we'll see how this works in  practice so the first thing i'm going to do   i'm going to target 18 psi everywhere i'm going to  do a pull in fourth gear watch what power it makes   then i'll bring it back to idle i'm going to go up  to 20 pounds give it another pull up to 22 pounds   another pull up to 24 pounds give it another pull  we'll look at what power level it makes each time   we increase by two pounds of boost then we'll  pull the data logs out and have a bit of a look at   how to compare all of those and make sure that  our target pressure is meeting our actual pressure   make sure that all of our duty cycles look  good and our long-term trims are working well   then all we'll need to do is  configure what boost we want where and she's still got it a few years later over  280 kilowatts of the wheels in this evo 9.   you'd tell i'm excited i've started tuning in  my evo 9. um geez i love these cars i might try   and get this one off devo but back to the  story at hand we just did a power run on   18 pounds on 20 pounds 22 and 24 pounds if we  look over at the dyno screen we can see that   each boost pressure made corresponding power  increases of sort of roughly 20 kilowatts per   2 psi or roughly 10 kilowatts per 1 psi that's  telling us that the engine's healthy and happy   the turbo charge has got plenty of half left  in it leaving it at about 280 or 285 kilowatts   fantastic the thing will drive great down the  bottom there we've got our air fuel ratio so   that's the one that's in the tailpipe of the car  that's coming off the mainline dyno independent   of the haltech wide beam controller that's in  the car nice to have two when we're tuning and   sometimes the car simply doesn't have a wideband  in it so it's nice that the dyno's got one   on the right hand side there we've got our  independent manifold pressure sensor so that's   t pieced into the inlet manifold of the car  it's measuring our boost pressure so if we   look over to the right there we can see that  we've got the red one roughly 18 pounds there   the blue one is telling us 20 pounds the purple  one is 22 pounds and the green one is 24 pounds   going to pull some logs out of the engine  management system we'll talk about the 24   pound run probably the biggest and most exciting  one but looking at the graphs on the dyno there   i'm really happy with how that's come out it's  almost the perfect demonstration coming back to   the engine management system i'm going to go up  the top of the page here we're going to click on   the data log manager it's been logging to the ecu  so now i'm going to extract those logs so that i   can view them in the data log viewer software so  we'll cruise down here and go okay that last log   just there open in datalog viewer i won't  open it there okay she's away so if i bring   up our engine rpm i'll bring up our manifold  pressure i might display that on a new trace   and that's showing us that we had 24 pounds  perfect and our boost control target pressure   i'll zoom in on that little bit there okay so  this shows us our power run so as the thing comes   up on boost it makes full boost at about 4500 rpm  something like that then sits right on our target   we've got about 0.3.4 psi of target error so i'm  not even going to worry about it that's perfect   if i come up here and i'm going to  open this one and go our boost control   output and our boost control base duty cycle  now as it came up it came on boost it sat at 33   duty cycle on the solenoid for the start delay  time so that means that it held at my get i   shouldn't say guess my educated guess or after  doing a bit of experimenting realizing that it's   going to need about 33 duty cycle in order  to obtain about 24 pounds of boost pressure   it sat on that start duty cycle then when it fell  into the closed loop strategy it started pulling   a few percent out it's gone back to 31 back to  30.7 duty cycle by the end of the power run so   we can see that there and we've got 30.9 percent  to achieve 24.2 pounds of boost pressure at   7200 rpm what i wanted to show you is what the  pid controller was doing so the proportional   affects the base the output the integral affects  the output and the derivative affects the output   so let's bring one up proportional output how much  work was the proportional doing to the output in   order to achieve that target and you know the  truth is it did very very little because our   start duty was so close in the first place it's  pulling out throughout the run 0.4 0.5 under 1   but because we're so close to the target and  remembering that proportional is percent based   on the target error so if the target error is  zero our proportional is going to fall to zero   if i bring up our integral output we're going to see by the end of the run so  remember that's the historical value so that's   looking at sort of not not cumulative but it's  looking at what the proportional has needed to do   in order to achieve the target and kind of keeps  that rolling average so that once the proportional   drops away the integral is there to hold the  target if we cruise along here to the right   here we're going to see that in order to achieve  our 22 psi by the end of the pull our integral is   pulling two percent out of that base duty cycle  so that means that we've got two percent integral   is getting removed we've got point two percent  of proportional that's two point two percent our output in total let's say somewhere  there so what should happen here   is we should end up with we've got what i thought  was going to be 33 minus 1.9 minus 0.1 results in   31 the actual output required in order to maintain  that target boost pressure there is our p and i in   action that's how it's working but all the way  back to the beginning again this video is called   boost by gear and what we've just done is just  tuned the car and just put more and more and   more boost in it but i haven't gone off on a  tangent i promise in order to do boost by gear   we first need to tune the maximum boost and we  need to know that when we target 18 pounds we   get 18 when we target 20 we get 20. target 24  we get 24. so now what i can do is go back and   have a bit of a think about what boost pressure  i want where so if i flick back to our tuning   software i'm going to come back out of our log  viewing software which i'm really enjoying using   then i'm going to come up here and this is where  the magic is going to happen and this is where   we talk about boost per gear so i'm going to go  say here and i'm going to tell this guy davo if   the intercooler water sprayer is off he's going to  get 18 pounds of boost pressure that's all there   is to it and that's going to be our base pressure  that's the lowest power the car is going to make   if i now go to on i'll flick on our intercooler  water sprayer and i'm going to say okay in fifth   and in third fourth probably probably fourth  fifth and sixth gear 60 throttle onwards 24   pounds of boost pressure in third gear 22  pounds in first and second 18 pounds then   at zero throttle or 20 throttle so the smallest  throttle opening we can have i'm going to target   18 pounds just so that if he's part throttling  20 or 30 mid corner we're not going to be sort   of spiking between 18 and 24 pounds as you're  pedaling it so it gives it a little bit more   drivability i'm going to come across and  do something like this and i'm going to go   h for horizontal so it'll horizontally linearize  all of those values and i'm going to end up   with a table something like this so if he's  cruising at 40 throttle in third gear he's going   to get a target of 20 pounds of boost pressure so  you can see how that's working you don't have to   specifically set this up exactly the same you can  think of all the different conditions that work in   your particular applications there's it's a four  dimensional table so we've got the x y and the   z axes the sky really is the limit in setting up  your boost control strategy versus your throttle   angle versus your inner cooler sprayer versus your  valet switch you can put some rocket switches in   this is the way to get it done it's a  really really nice really simple solution   all contained within the engine management system  so you don't have to add any other complexity   if you've got a haltech ic7 dash in the car you  can also display your trim position you can also   display your target boost pressure on the dash so  that when you flick your button on the dash it'll   tell you target 22 24. if you get really excited  it'll say target 30 and that's when things start   getting exciting remembering as well we haven't  gone through the whole mechanical boost control in   this particular car we did do a heap of that with  that r35 video from the other week and we'll put   a link to that in the comments so if you want to  know more about power management and boost control   strategies flick over that r35 video and take a  look there as well well we've come to an end today   i've had an absolute ball with the evo 9 it really  makes me feel at home in here i absolutely love it   i'm going to have to organize with davo that  we might need to use this test mule for a few   extra tests you know maybe drive it home back  and forward a few times just to you know really   get a feel for it as always thanks so much for  watching i know it's always a bit of technical   content i appreciate you sticking to the end as  always my name's still scott catch you next time you

Channel: Haltech

Views: 41,827

Keywords: haltech, ecu, engine management, tuning, modified cars, race cars, technically speaking, tuning fork, efi tuning, boost control, engine tuning, street car tuning, boost by gear, haltech elite, haltech nexus, boost tuning, turbo tuning, boost controller, ecu boost control, car tuning, how to tune a car, reflash tuning, engine management system, tuning efi

Id: rbi8zO5Icto

Length: 36min 11sec (2171 seconds)

Published: Thu Oct 28 2021