Pages: [1] 2 3 ... 31
Author Topic: Opinions: using KFLBTS vs LAMFA for fuel all the time?  (Read 178726 times)
elRey
Hero Member
*****

Karma: +21/-0
Offline Offline

Posts: 531


« on: July 12, 2010, 12:21:39 PM »

Opinions: using KFLBTS vs LAMFA for fuel all the time?

I really didn't like the idea of mapping fuel by requested torque% via pedal position, so I chose to use KFLBTS (current load).

Any thoughts why this may be a bad decision?

Thanks,
Rey
Logged
hammersword
Full Member
***

Karma: +29/-2
Offline Offline

Posts: 134

Revlimit owner


WWW
« Reply #1 on: July 12, 2010, 05:13:29 PM »

I think we have discuss that!

Lamfa axis is not PEDAL position!

KFLF is your answer if you like to have different fuel for different load. You have to calibrate ECU with a totally diferent way to make it work like that!

KFLBTS option is WRONG, there is the EGT model behind KFLBTS....
Logged

www.revlimit.gr
The Motronic Specialists....
elRey
Hero Member
*****

Karma: +21/-0
Offline Offline

Posts: 531


« Reply #2 on: July 12, 2010, 08:10:40 PM »

From my reading....

EGT is just a trigger for KFLBTS.

TABGBTS = on/off
FBSTABGM = EGT -> % of BTS correction to be used.

I set TABGBTS = 200*C (always on)
and FBSTABGM :
200 => 0
210 => 1
230 => 1
900 => 1

So, once 'calculated' EGT hits 210* I get full control of AFR via KFLBTS. It doesn't matter that my EGT model is off as long as 200*C is low enough.

KFFDLBTS all = 1 (deactivated)
LAMFA all = 1 (deactivated)

I tried, and it works as I expected.
« Last Edit: July 12, 2010, 08:15:05 PM by elRey » Logged
elRey
Hero Member
*****

Karma: +21/-0
Offline Offline

Posts: 531


« Reply #3 on: July 12, 2010, 08:18:52 PM »

Lamfa axis is not PEDAL position!

requested torque% via pedal position
Logged
hammersword
Full Member
***

Karma: +29/-2
Offline Offline

Posts: 134

Revlimit owner


WWW
« Reply #4 on: July 13, 2010, 02:59:11 AM »

ok didn't noticed the last!

KFFDLBTS = 1 is not disabled but enable the KFLBTS. If you set it to 0 then you deactivate with the RIGHT way the BTS!

When ECU understand "high temps" that means that you run over TABGBTS thershold, it calculates with different way a lot of things for high EGT!

So you have to calibrate the EGT model.
Logged

www.revlimit.gr
The Motronic Specialists....
elRey
Hero Member
*****

Karma: +21/-0
Offline Offline

Posts: 531


« Reply #5 on: July 13, 2010, 07:11:23 AM »

KFFDLBTS = 1 is not disabled but enable the KFLBTS. If you set it to 0 then you deactivate with the RIGHT way the BTS!

Sorry, you're right. I set this to 0 not 1. KFFDLBTS is an additive to KFLBTS.

When ECU understand "high temps" that means that you run over TABGBTS thershold, it calculates with different way a lot of things for high EGT!

So you have to calibrate the EGT model.

My EGT model would be off whether I'm tuning or not since my setup is no where near stock -> http://forums.vwvortex.com/showthread.php?4260387

For arguement's sake, say my EGT model was corrected. I would still try to use LAMBTS for fueling the same way.

TABGBTS looks to ONLY be used in LAMBTS and no where else. It doesn't look like it's used to affect anything else BUT on/off of LAMBTS which only affects target lambda. If I'm wrong, please give me one example where TABGBTS affects anything other than target lambda.



edit: I see EGT Limp mode, but several other conditions need to be TRUE also before that is enabled.
« Last Edit: July 13, 2010, 07:33:52 AM by elRey » Logged
ArgDub
Full Member
***

Karma: +57/-1
Offline Offline

Posts: 202


« Reply #6 on: July 14, 2010, 10:08:35 AM »

I've been following this in the other forum with much interest, great info!

Fotis, KFFDLBTS = 0 disables KFDLBTS not KFLBTS.

Rey, setting TABGBTS and FBSTABGM to 200ºC, gives you lambda control through KFLBTS, right?
Logged
elRey
Hero Member
*****

Karma: +21/-0
Offline Offline

Posts: 531


« Reply #7 on: July 14, 2010, 11:39:30 AM »

Rey, setting TABGBTS and FBSTABGM to 200ºC, gives you lambda control through KFLBTS, right?

Yes it did. I did a little more testing and 940*C TABGBTS = ~760*C pre-cat temp via vag-com and  810* TABGBTS = ~600*C.
I now have it set to 800-810. This makes LAMBTS off during lite cruise and on with any kind of load. But it's not quite a solid threshold. It moves depending of current airflow thru MAF and current IAT.
i.e.
with TABGBTS set @ 800-810*, logs showed LAMBTS coming on at different VAG-COM pre-cat temps in different situations:
low speed when AIT was high and airflow was low, ECU 'calulated' EGT a lot higher (relative to VAG-COM pre-cat temp) than when I was going faster where IAT was low and airflow was high.

I'll probably set it back lower. I don't think it matters as long as KFLBTS is set to 1 in areas where you don't want it (to let other functions use a higher AFR when applicable).
« Last Edit: July 14, 2010, 02:18:53 PM by elRey » Logged
ArgDub
Full Member
***

Karma: +57/-1
Offline Offline

Posts: 202


« Reply #8 on: July 14, 2010, 01:00:26 PM »

I'll probably set it back lower. I don't think it matters as long as KFLBTS is set to 1 in areas where you don't want it (to let other functions use a higher AFR when applicable).

Lambdabts is KFLBTS + (KFDLBTS * KFFDLBTS). Setting KFLBTS to 1 where you don't need it won't disable bts, you also have to set KFFDLBTS = 0 to disable it.

KFDLBTS is an additive correction for bts and is function of ignition timing efficiency.
« Last Edit: March 01, 2016, 12:09:34 AM by nyet » Logged
elRey
Hero Member
*****

Karma: +21/-0
Offline Offline

Posts: 531


« Reply #9 on: July 14, 2010, 02:15:02 PM »

I've already set KFFDLBTS = 0.
Logged
lulu2003
Full Member
***

Karma: +11/-1
Offline Offline

Posts: 242



« Reply #10 on: August 08, 2010, 11:03:10 AM »

Opinions: using KFLBTS vs LAMFA for fuel all the time?
I really didn't like the idea of mapping fuel by requested torque% via pedal position, so I chose to use KFLBTS (current load).
Any thoughts why this may be a bad decision?

I think the idea behind LAMFA is the WOT fuel-enrichment and not a base fueling map (like on many other ECUs).
This is why LAMFA depends on torque demand (by pedal) and not (actual) load. Demand is always ahead of actual load (timely)

2nd I do not like the idea of fooling the ECU to be in BTS to inforce a certain function. You always lose a bit of build-in security, don't you?

What is the intention of your way to fuel? did you get something you could not reach before?

cheers
Logged
lulu2003
Full Member
***

Karma: +11/-1
Offline Offline

Posts: 242



« Reply #11 on: August 09, 2010, 04:02:03 PM »

oh, I missed a very important thing: seems like that lambda'ing only by KFBTS (and leave LAMFA = (1x1)) is already done in at least 2 original files by Audi in 1,8T and 2,7T.  Undecided
Logged
Goszu
Newbie
*

Karma: +1/-0
Offline Offline

Posts: 4


« Reply #12 on: August 11, 2010, 03:03:30 PM »

Hello.
I have set my 1.8T ME7.5 fuelling only by LAMFA (flat at 1 plus some enrichment at WOT) and KFLBTS. KFFDLBTS all 0.
But I am trying to do it better. The KFFDLBTS and KFDLBTS tables works very good (seems that the ignition timing influence
on lambda is properly done by ECU), way better than simply KFLBTS, especially at middle load (part throttle).
The only problem is that this mechanism gives too rich mixture at high rpm and load (near 0.75). I would like to correct it,
but to make it working properly I think one information more is needed. What is on Y axis of KFDLBTS (%) ? Does anybody know ?
With that info we would know what to correct (KFFDLBTS, KFDLBTS or both) to make fuelling work yet better.

Cheers!
Logged
lulu2003
Full Member
***

Karma: +11/-1
Offline Offline

Posts: 242



« Reply #13 on: August 11, 2010, 03:27:41 PM »

KFFDLBTS all 0 would mean you disabled the Lambda changes on ignition eta.
part throttle should be another kind of focus with resulting lambdas very near 1 or slightly above?

KFDLBTS is f(nmot,delta-ignition eta)

Logged
Goszu
Newbie
*

Karma: +1/-0
Offline Offline

Posts: 4


« Reply #14 on: August 12, 2010, 12:16:49 PM »

Quote
KFFDLBTS all 0 would mean you disabled the Lambda changes on ignition eta.
Yes, it was disabled. Now it's enabled and the engine runs better. Timing is also affected.

Quote
part throttle should be another kind of focus with resulting lambdas very near 1 or slightly above?
The part throttle areas in my program were almost all set to 1 via KFLBTS except for high load & high rev (enrichment up to 0,805).

Quote
KFDLBTS is f(nmot,delta-ignition eta)
Thanks for info. I left this map stock, while KFFDLBTS is lowered by about 50% for now.
That is enough for the KFDLBTS & KFFDLBTS not to enrich the mixture too much.
I'm still testing, but I think results are better than with KFFDLBTS disabled.

How do you tune that ? KFFDLBTS disabled or not ?
And how rich do you go in your engines ?
Any comments highly appreciated.

Regards
Goszu
Logged
Pages: [1] 2 3 ... 31
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.023 seconds with 17 queries. (Pretty URLs adds 0s, 0q)