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Author Topic: Disabling EGT correction?  (Read 14330 times)
masterj
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« on: January 08, 2012, 08:37:20 AM »

Is it possible to disable EGT for part protection correction? Atleast temporary to test some things...
If possible which maps should I look at?

Thanks
« Last Edit: January 08, 2012, 08:40:33 AM by masterj » Logged

TheDSI
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« Reply #1 on: January 08, 2012, 09:07:41 AM »

you want to disable BTS ?
set tabgbts to 1250°C and it will never be active .
« Last Edit: January 08, 2012, 09:11:33 AM by TheDSI » Logged
masterj
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« Reply #2 on: January 08, 2012, 09:13:31 AM »

you want to disable BTS ?
set tabgbts to 1250°C and it will never be active .

Yes, thank you
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masterj
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« Reply #3 on: January 08, 2012, 09:23:34 AM »

BTW: Could someone explain me why my EGT skyrockets after I've disconnected aftercat o2 sensor?? Does EGT model takes some variables from post cat o2 sensor??
I have no cat, no postcat o2 sensor and no sai. They're coded out (with the help of s4wiki) and no DTC are stored, but my EGT model goes out of it's mind!

Please see attached log in EcuXPlot software or excel Wink

And this is with E85 and stock tune (except for KRTKE and TVUB)!
« Last Edit: January 08, 2012, 09:27:39 AM by masterj » Logged

phila_dot
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« Reply #4 on: January 08, 2012, 11:48:36 AM »

BTW: Could someone explain me why my EGT skyrockets after I've disconnected aftercat o2 sensor?? Does EGT model takes some variables from post cat o2 sensor??
I have no cat, no postcat o2 sensor and no sai. They're coded out (with the help of s4wiki) and no DTC are stored, but my EGT model goes out of it's mind!

Please see attached log in EcuXPlot software or excel Wink

And this is with E85 and stock tune (except for KRTKE and TVUB)!

Are you sure you're not running lean?

Do you have wideband?

Are we talking about BTS or ATR?

I wouldn't be so quick to disable BTS.
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Tifon
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« Reply #5 on: January 08, 2012, 12:06:09 PM »

I'm not an expert but E85 burns slower than gasoline. If you have stock timming then the combustion is too retarded, so fuel is burning in your exhaust. Just add advance.
« Last Edit: January 08, 2012, 12:15:19 PM by Tifon » Logged
TTQS
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« Reply #6 on: January 08, 2012, 12:16:39 PM »

A few thoughts.

You need to log tats_w (the actual EGT from the EGT sensor). Is it functional on your car? All I am seeing in your log are three modeled temperatures and EGT for component protection. mrfa_w would have been useful too and rl_w so we can get a handle on the engine load.

That said, when you get to high engine speeds, your EGT for component protection is hitting high 870˚C which doesn't seem unreasonable to me. You don't seem to be running especially lean either with AFR down to 0.75 (rich best torque rule-of-thumb). Have a look at my log here and see how it compares.

http://nefariousmotorsports.com/forum/index.php?topic=1296.msg12400#msg12400

The variables shaded in yellow are the bare minimum I would be logging on a routine basis. I measure EGT up to 930˚C region on extended high load pulls so I wouldn't be overly concerned about 870˚C.

I can only echo phila_dot's caution about disabling LAMBTS because you'll have no protection then given that you already have no pre and post-cat O2 sensors active.

TTQS
« Last Edit: January 08, 2012, 12:27:30 PM by TTQS » Logged
TTQS
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« Reply #7 on: January 08, 2012, 12:30:01 PM »

I'm not an expert but E85 burns slower than gasoline. If you have stock timming then the combustion is too retarded, so fuel is burning in your exhaust. Just add advance.

Surely a stock tune will cope with E85? I haven't heard of anyone requiring a remap because they have started using high ethanol fuel. I haven't studied it myself, but I understand that ethanol burns cooler than gasoline so that shouldn't be the cause of high EGTs. I don't see why it should be burning in the exhaust either.

TTQS
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masterj
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« Reply #8 on: January 08, 2012, 12:38:25 PM »

A few thoughts.

You need to log tats_w (the actual EGT from the EGT sensor). Is it functional on your car? All I am seeing in your log are three modeled temperatures and EGT for component protection. mrfa_w would have been useful too and rl_w so we can get a handle on the engine load.

That said, when you get to high engine speeds, your EGT for component protection is hitting high 870 degC which doesn't seem unreasonable to me. You don't seem to be running especially lean either with AFR down to 0.75 (rich best torque rule-of-thumb). Have a look at my log here and see how it compares.

http://nefariousmotorsports.com/forum/index.php?topic=1296.msg12400#msg12400

I measure EGT up to 930 degC region on extended high load pulls so I wouldn't be overly concerned about 870 degC.

I can only echo phila_dot's caution about disabling LAMBTS because you'll have no protection then given that you have no pre and post-cat O2 sensors.

TTQS

In my ME7.5 1.8T Passat there are no EGT sensors, everything is based on model... I have wideband precat o2 though... Smiley Now car is hitting 870C with only 0.5 bar of boost. Normally my stock KO3 would boost 0.7-0.8bar and that is what I have to sort out before going to the kmirl/iop/l....

I can log about 20 variables with me7logger at 20 samples per second. Could you tell me what 20 variables are most important to test what is limiting my boost?

  • gangi
  • nmot_w
  • lamfa_w
  • lamsbg_w
  • lamsoni_w
  • lambts_w
  • mshfm_w
  • plsol_w
  • pvdkds_w
  • ldtv
  • wped_w
  • mrfa_w
  • rlsol_w
  • rl_w
  • rlmax_w
  • tats_w  
  • tabgbts_w
  • zwgru
  • zwopt
  • zwist
  • dwkrz_0
  • dwkrz_1
  • dwkrz_2
  • dwkrz_3
  • tans
  • pu_w

BTW: If you're going to E85 you'll have to open your injectors for 30% more time than normal fuel
« Last Edit: January 08, 2012, 12:44:03 PM by masterj » Logged

TTQS
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« Reply #9 on: January 08, 2012, 01:52:33 PM »

If you're going to E85 you'll have to open your injectors for 30% more time than normal fuel

Why is that? I am confused as to how fuel retailers can sell E85 when engines require changes to use it.

I can't really shed any light on the boost issues, sorry.
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Tifon
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« Reply #10 on: January 08, 2012, 02:12:56 PM »

The stoich afr of e85 is 9,x (i don't know exactly) instead of 14,7, because e85 contains more oxygen. This is why you should increase 30% of fuel or you would go lean.
You can use e10 with stock tune because the ecu can adapt this little percent, but if you use e85 the ecu will throw a lean error.
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masterj
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« Reply #11 on: January 08, 2012, 02:13:49 PM »

The stoich afr of e85 is 9,x (i don't know exactly) instead of 14,7, because e85 contains more oxygen. This is why you should increase 30% of fuel or you would go lean.
You can use e10 with stock tune because the ecu can adapt this little percent, but if you use e85 the ecu will throw a lean error.

Yes, you are right
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masterj
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« Reply #12 on: January 08, 2012, 02:15:26 PM »

Why is that? I am confused as to how fuel retailers can sell E85 when engines require changes to use it.

I can't really shed any light on the boost issues, sorry.

TTQS, I logged data with every variable that was in your file yellow. Could you take a look?
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masterj
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« Reply #13 on: January 08, 2012, 02:50:46 PM »

As you see my engine load is lower than requested and boost is cut off
« Last Edit: January 08, 2012, 02:56:50 PM by masterj » Logged

TTQS
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« Reply #14 on: January 09, 2012, 02:52:00 AM »

The stoich afr of e85 is 9,x (i don't know exactly) instead of 14.7, because e85 contains more oxygen. This is why you should increase 30% of fuel or you would go lean.

Yes, of course. I should beat myself with birch sticks. Being an ex-chemist, I should have known that!  Roll Eyes Possibly I was reading E85 and thinking E15. The premium 99 RON fuel I use regularly at the supermarket is up to 15% bioethanol. The stoichiometric ratio is 9 exactly for ethanol going by the table of page 14 of Engine Management: Advanced Tuning by Greg Banish, so weighting for 85% ethanol and 15% gasoline would probably give a stoichiometric ratio of 9.855 for E85 fuel assuming it's a linear scale...

Some more info was posted here by rob.mwpropane:

http://nefariousmotorsports.com/forum/index.php?topic=1185.msg12763#msg12763
« Last Edit: January 09, 2012, 03:54:16 AM by TTQS » Logged
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