Nottingham
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« Reply #195 on: July 19, 2015, 04:09:52 PM »
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Calculated EGT below TABGBTS and TLAFA limit met = LAMFA Calculated EGT above TABGBTS = KFLBTS + the scalars Final lambda is affected (KFLBTS + (DLBTS * KFFDLBTS)) by DLBTS and KFFDLBTS which are both scalar (delta) values. TAIKRBTS = 800°CTANHKSAO = 1263°C TANVKBTS = 1263°C TAVHKBTS = 1263°C TAVHKSAO = 1263°C TAVROBTS = 1200°CTAVVKBTS = 1263°C TAVVKBTSH = 1263°C TAVVKBTSP = 1263°C TAVVKBTSW = 1263°C TAVVKSAO = 1263°C TKIHKSAO = 1263°C TKIVKBTS = 1263°C TKIVKSAO = 1263°C TAIKRBTS appears to be the EGT threshold here as the other limits besides TAVROBTS are disabled. But still, if increasing the limits is wrong there is no way that the EGT limit won´t be reached and KFLBTS used for fuelling  |
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nyet
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« Reply #196 on: July 19, 2015, 04:20:37 PM »
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Ok so basically you´re saying:
- Using any BTS map for fuelling is wrong
- Changing BTS activation thresholds is wrong
No, I am mostly just making an almost semantic argument. Requested lambda is the lowest of lamfa, lamfawk, and lambts. The correct question is: "how do prevent lambts from dropping below lamfa, until I want it lower than lamfa". So please do explain how the hell one does one force the ECU to use LAMFA then?
I could set the LAMFA map to 0.6 and still the ECU won´t use it.
you're not looking to disable BTS. You're looking to make it do what you want to do to keep EGTs under control, but not at the cost of going too rich too soon. |
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« Last Edit: July 19, 2015, 04:22:19 PM by nyet »
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majorahole
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« Reply #197 on: July 19, 2015, 04:36:20 PM »
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Calculated EGT below TABGBTS and TLAFA limit met = LAMFA Calculated EGT above TABGBTS = KFLBTS + the scalars Final lambda is affected (KFLBTS + (DLBTS * KFFDLBTS)) by DLBTS and KFFDLBTS which are both scalar (delta) values. TAIKRBTS = 800°CTANHKSAO = 1263°C TANVKBTS = 1263°C TAVHKBTS = 1263°C TAVHKSAO = 1263°C TAVROBTS = 1200°CTAVVKBTS = 1263°C TAVVKBTSH = 1263°C TAVVKBTSP = 1263°C TAVVKBTSW = 1263°C TAVVKSAO = 1263°C TKIHKSAO = 1263°C TKIVKBTS = 1263°C TKIVKSAO = 1263°C TAIKRBTS appears to be the EGT threshold here as the other limits besides TAVROBTS are disabled. But still, if increasing the limits is wrong there is no way that the EGT limit won´t be reached and KFLBTS used for fuelling it won't be reached right away if u lower LAMFA and remove the timer on it. in my experience it can still be reached on a long pull, or sometimes in spirited driving with a lot of WOT pulls. not always tho, like I said, I raised my TAIKRBTS to 850°c, but I have a 3" cat-less downpipe |
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prj
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« Reply #198 on: July 20, 2015, 04:56:36 AM »
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I could set the LAMFA map to 0.6 and still the ECU won´t use it.
Of course it will. READ THE FR. LAMKO module. Stop posting until you know this by heart. |
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overspeed
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« Reply #199 on: July 20, 2015, 08:43:04 AM »
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Some ECU's are coded to work on the difference between basic ignition angle efficiency and retarded ignition angle efficiency. In this case with no retard DLBTS and KFFLDBTS will not kick in. Some ECU's look at ignition angle efficiency in absolute terms, i.e difference in efficiency from KFZWOP and zwout. Here you will get an AFR of KFLBTS multiplied by the relvant values in KFFDLBTS and DLBTS.
Correctly tuned, you will have your targeted AFR in normal conditions, and a richer AFR if ignition timing retards from your basic ignition angle.
Rick
Ok, we have two diferent ways to code, as I usually see lambda lower than KFLBTS and it disapers after "0"ed KFFDLBTS I assume that I´m in the second way ( KFZWOP different than zwout triggering DLBTS), considering I have no knock at all RPM ranges and loads : 1 - Can I assume KFZWOP is lower than it could be ? (perhaps 25% ethanol in blend here in Brasil) 2 - To achieve better behavior I should a - code to "first way" ( "difference between basic ignition angle efficiency and retarded ignition angle efficiency") (if it´s possible, and HOW to make it ?) b - decrease DLBTS / KFFDLBTS to keep lambda as it should be (don´t look too smart to me at now, but it work very good indeed) c - increase KFZWOP and keep DLBTS as an ultimate defense for knock (fuel quality)? 3 - I allways though KFLAMKRL was the enrichment related to knock, used to think DLBTS/KFFDLBTS was only to increase enrichment as EGT rises beyond the trigger |
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majorahole
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« Reply #200 on: July 20, 2015, 12:10:52 PM »
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this is med9, don't forget, so there is also a bts map with the flapper open
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Nottingham
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« Reply #201 on: July 22, 2015, 03:21:29 AM »
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I was looking for the maps reponsible for timing retardation at high EGTs but couldn´t find any.
Looked through "ATM" but the only even remotely similar map was KFATZWMS/2 (Kennfeld Zündwinkelkorrektur für Krümmerabgastemperatur).
I would like to temporarily disable the EGT retardation in order to get my ignition maps in the best possible order.
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prj
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« Reply #202 on: July 22, 2015, 05:32:27 AM »
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I was looking for the maps reponsible for timing retardation at high EGTs but couldn´t find any.
Looked through "ATM" but the only even remotely similar map was KFATZWMS/2 (Kennfeld Zündwinkelkorrektur für Krümmerabgastemperatur).
I would like to temporarily disable the EGT retardation in order to get my ignition maps in the best possible order. Timing retardation at high EGT? What? Why would you retard timing at high EGT? To grenade the engine? This is also why it does not exist in the ECU, it is absurd. |
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overspeed
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« Reply #203 on: July 22, 2015, 11:11:33 AM »
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So, that was a doubt mine too... ECU takes no action related to EGT x advance ?
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nyet
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« Reply #204 on: July 22, 2015, 11:13:17 AM »
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So, that was a doubt mine too... ECU takes no action related to EGT x advance ?
I don't know about MED9 but there is certainly no timing intervention from EGT in ME7. |
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overspeed
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« Reply #205 on: July 22, 2015, 11:20:21 AM »
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Make sense as advance make huge difference in EGT, what part of MED9.1 FR it would be (if there is obvioulsy)
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nyet
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« Reply #206 on: July 22, 2015, 11:38:46 AM »
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Make sense as advance make huge difference in EGT, what part of MED9.1 FR it would be (if there is obvioulsy)
Too much timing or too little timing BOTH cause high EGTs.... However, the ECU will already never add too much timing; it will only pull timing (for KR, torque intervention, etc), but why would it try to RE-ADVANCE timing to prevent high EGTs if it is already running at the knock or torque limit? |
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prj
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« Reply #207 on: July 22, 2015, 06:07:30 PM »
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I have a simple suggestion. Before tackling a difficult to tune ECU that is calibrated by many engineers at the factory at least get the basic concepts of an internal combustion engine straight. Such as timing effect on EGT, fuel effect on EGT, fuel effect on power and so on.
Small steps...
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Nottingham
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« Reply #208 on: July 23, 2015, 02:23:53 AM »
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Could someone post TLAFA offset for some binary, so I could look for reference?
I thought I already had it, but it´s incorrect.
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ddillenger
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« Reply #209 on: July 23, 2015, 02:29:44 AM »
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I have a simple suggestion. Before tackling a difficult to tune ECU that is calibrated by many engineers at the factory at least get the basic concepts of an internal combustion engine straight. Such as timing effect on EGT, fuel effect on EGT, fuel effect on power and so on.
Small steps...
I agree, and these threads lately are starting to get frustrating. I'm not sure where to go from here, but I feel that it detracts from the site to have a bunch of people that don't understand the fundamentals of what they're doing representing our community. |
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Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience!
Email/Google chat:
DDillenger84(at)gmail(dot)com
Email>PM
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