Dropout
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« on: April 22, 2014, 01:13:33 AM »
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Hi guys,
I've bean reading this forum for quite some time and it's has bean very helpful. However I couldn't find the answer for the best way to tune for loads above 10ms ? In all the definition files for the me3.8.3 the maximum value for the load column is 10ms (KFLF and KFZW ), but the max load value is 12.750(FF - hex), so how does the ECU calculate fuel and timing for values above 10ms, does it extrapolate or use the last value (in this case the value for 10ms load ) ? What is the best method to tune for loads above 10.00ms ? I was thinking about rescaling the load axis so the last column is max load (12.750) and the one before it is 10.00, this way the ECU should interpolate between the two values.
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overspeed
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« Reply #1 on: April 22, 2014, 08:52:42 AM »
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Based on a plenty of guys said you don´t want to reach 12,75ms  In this point, 10ms will be enough... ECU will use same value above 10ms The only interesting point I can see, is if you want to make some kind of protection when actual load is bigger than you expect... in this case you use the last colum just to maker a huge enrichment and advance decay to try to protect engine... |
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Dropout
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« Reply #2 on: April 22, 2014, 11:59:48 AM »
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Yes, I've read that if you hit loads 12.75 or more you have to downscale KHFM which leads to changing/scalling of the ignition/fuel maps. I've seen some tunes where the tuner just capped of the load protections and tuned the car for the boost it runs (load above 12.75ms) i.e. the fuel and ignition values at 10ms load were set for the boost/load the car run, but in my opinion that's not good since you bypass the protections . Another drawback is that with this method that ignition and fueling will not be optimal for loads that are really around 10ms since they will be setup for high boost/loads.
I'm interested in rescaling the load axis since I have the following problem. I'm running an EBC which has two boost settings 1.0 and 1.2 bar (currently, I'd like to go 1.5 bar but after I rescale KHFM) . At one bar I'm hitting loads of ~10ms - 10.5ms, when I tune the fuel/ignition for 1 bar it is not optimal for 1.2 bars since at 1.2 I'm hitting loads ~11.5-12ms. My idea is to have the last load position say 12ms and the one before it 10ms so I can tune the ignition and fuel to be optimal for both boost settings (I assume load values between the two will interpolate?). Does this make sense or am I shooting in the wrong direction ?
P.S. My current setup is a t3/t4 turbo, bigger MAF (calibrated), 380cc/min injectors and FMIC.
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« Last Edit: April 22, 2014, 12:45:09 PM by Dropout »
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overspeed
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« Reply #3 on: April 22, 2014, 03:55:25 PM »
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Well... you´ll be losing resolution in lower load areas, that you are most of the time
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Dropout
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« Reply #4 on: April 22, 2014, 11:34:44 PM »
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Overspeed, thanks . I guess when modifying/rescaling an axis you always loose a bit of resolution . So in this case would it be better to just down scale KHFM so the target boost/loads fall into the 10ms region ?
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Dropout
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« Reply #5 on: April 22, 2014, 11:55:46 PM »
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Looked at down scaling KHFM and it looks like a lot of maps must be changed to get the timing and fueling right . KHFM,FGAT0,KFLF,KFZW.0-2,KFZWS,KFZWES,TLRAN.0-1,KFTLWS.0-2,TLST.0-1 and by the looks of it a few others. Looking at all this maps I get why some tuners just set the protection maps to FF and tune the ignition and fuel (rows at 10ms) to the max boost/load  . |
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overspeed
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« Reply #6 on: April 23, 2014, 06:42:58 AM »
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Don´t forget to mention that a lot of maps interact with other (IAT advance correction for example).
My opnion is the AFR (or advance) you want to use for 10 to 11ms will be not that diferent at all... the old "better be safe that sorry"
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prj
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« Reply #7 on: April 23, 2014, 02:11:26 PM »
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How are you going to control boost if the load is at 12.75?
If those "tuners" used MBC's then they are a joke.
Basically there are two things you do not ever want to happen on this ECU:
1. Hit 12.75 load.
2. Max out the MAF.
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Dropout
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« Reply #8 on: April 28, 2014, 11:14:34 PM »
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My mistake, I said tuners should have said tuned files. Your right some use MBC others EBC . I also currently use a EBC since I like the options it provides - 2 boost levels switched at the press of a button, easy and fast adjustment of the boost (if I want to modify them), over boost function, overboost warning and protection etc.
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ddillenger
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« Reply #9 on: April 28, 2014, 11:41:02 PM »
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My mistake, I said tuners should have said tuned files. Your right some use MBC others EBC . I also currently use a EBC since I like the options it provides - 2 boost levels switched at the press of a button, easy and fast adjustment of the boost (if I want to modify them), over boost function, overboost warning and protection etc.
You can limit boost with your right foot. |
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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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eliotroyano
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« Reply #10 on: April 29, 2014, 05:25:16 AM »
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Looked at down scaling KHFM and it looks like a lot of maps must be changed to get the timing and fueling right . KHFM,FGAT0,KFLF,KFZW.0-2,KFZWS,KFZWES,TLRAN.0-1,KFTLWS.0-2,TLST.0-1 and by the looks of it a few others. Looking at all this maps I get why some tuners just set the protection maps to FF and tune the ignition and fuel (rows at 10ms) to the max boost/load . Don´t forget to mention that a lot of maps interact with other (IAT advance correction for example).
My opnion is the AFR (or advance) you want to use for 10 to 11ms will be not that diferent at all... the old "better be safe that sorry"
How are you going to control boost if the load is at 12.75?
If those "tuners" used MBC's then they are a joke.
Basically there are two things you do not ever want to happen on this ECU:
1. Hit 12.75 load.
2. Max out the MAF.
Then scaling or modifing KHFM and changing all it related maps in those old Motronic ECUs could generate a new large and polemic thread. |
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overspeed
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« Reply #11 on: April 29, 2014, 12:03:35 PM »
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Bigger MAF + MLHFM => Right g/s readings, but load will increase in proportion (and shall be more than 12,75ms limit) Bigger MAF + MLHFM + KHFM => Rigth g/s readings and load will be lowered again to "normal" levels (10ms axis) The logic can bem simplified to Ld = K x MAF/KHFM If you raise MAF value (in g/s by using rigth MLHFM) then Ld value will raise it too... and shall touch 12,75ms/umdr to keep Ld in "sane" values you raise KHFM in same proportion... |
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checcoa3
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« Reply #12 on: May 01, 2014, 02:08:25 AM »
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I have tried to do many tests to get a good tune but the results are not satisfactory.
I have 72mm maf and 350cc injectors bosch red.
Can anyone give me advice?
Thanks in advance.
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prj
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« Reply #13 on: May 03, 2014, 04:20:09 PM »
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It's pointless only scaling KHFM, you then have to remap the entire ECU for it to work halfway decently, which takes absolutely AGES, even with an emulator on the dyno.
Much easier to scale KHFM far enough that you don't hit 12.75 load and then scale FGAT0 to compensate for the rest.
EBC's are for people who can't tune, and when the ECU is tuned correctly you modulate the amount of load you want with your right foot.
Anything an EBC does the stock ECU always does better.
Only point in them is when you have a NA car that you have turbocharged and are using the stock ECU, but most work like cr*p. Prime example apexi, which is utterly useless and creates huge amount of artificial turbo lag…
As for getting a good tune - need proper data logger with boost, rpm, wideband, VCDS, knowledge how the ECU works, and of course a realtime emulator, else it's impossible to get it tuned right.
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Dropout
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« Reply #14 on: May 03, 2014, 11:01:38 PM »
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But wouldn't only scaling KHFM and FGAT0 throw the igntion timing off ? In this case you still would have to retard the ignition tables in order not to have a lot of knock retard, question is could you get away with it if you only scale KFZW tables (log timing and modify these tables accordingly) .
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