NefMoto

Technical => Tuning => Topic started by: ricekikr on October 16, 2012, 10:54:24 PM



Title: 2.0 coils on AEB - Dwell time
Post by: ricekikr on October 16, 2012, 10:54:24 PM
Has anyone used the 2.0 dwell times?

2.0 - 11.9 v = 2.700 / 14v = 2.1
1.8 - 11.9 v = 2.340 / 14v = 1.98

Did you get better drivability or anything positive? Trying to eliminate some cold-start misfires been having.


Title: Re: 2.0 coils on AEB - Dwell time
Post by: professor on October 17, 2012, 12:20:20 AM
I use 2.0TSI coils too.
I have not changed dwell time and run with iridium BKR8EIX plugs.
No misfires on cold start.


Title: Re: 2.0 coils on AEB - Dwell time
Post by: ricekikr on October 17, 2012, 01:16:56 AM
I was just thinking that adjusting the dwell would band-aid this. And if 2.0 dwell is the proper dwell to use, it should have little effect of coil life (unless Audi/VW are pushing it with the 2.0 dwell values). Or maybe just add more dwell when engine is cold.

I don't think my cold-start is caused by the coils. I'm leaning towards:
--Wahlbro255(no checkvalve?) combined with Siemens870cc(poor atomization or dribbles when first started (low pressure) that it fouls spark plugs?)
--AHA throttle (some people also started having issues with AHA/vr6 tb - maybe because ECU thinks it has less load).

Never had issues with my previous setup 630cc / same wahlbro pump / stock TB / bkr7e .025 gap (.040 now).

Installed the 2.0 coils because I had it with me, and thought maybe it'd help. It lessened the misfires a lot (it was almost undrivable when cold before). But both stock coil and 2.0 perform perfectly @35+psi.


Title: Re: 2.0 coils on AEB - Dwell time
Post by: prj on October 17, 2012, 04:44:50 AM
2-2.5ms is right.

Stock on many earlier big coils is 4ms and up.

The coils will burn out prematurely if you do not change the dwell setting.
But it will not cause misfires unless they are already dead.


Title: Re: 2.0 coils on AEB - Dwell time
Post by: ricekikr on October 17, 2012, 05:10:14 AM

Stock on many earlier big coils is 4ms and up.


What exactly is "earlier"? The 1.8t values I got from both a me3.82 and me5.92 1.8t ecu file. They were both slightly lower than the 2.0 coils.

Guess I should up the dwell a little to get full advantage of the 2.0 coils?


Title: Re: 2.0 coils on AEB - Dwell time
Post by: professor on October 17, 2012, 07:14:00 AM
We are talking about KFSZT?

prj says optimal dwell time for 2.0 coils its between 2-2.5ms.

Unfortunately cant locate this KFSZT on 2.0TFSI ori (think does not exist can't find it on MED9 FR) either KFTSRKM.
Only KFTSRL.


Title: Re: 2.0 coils on AEB - Dwell time
Post by: prj on October 17, 2012, 08:42:05 AM
What exactly is "earlier"? The 1.8t values I got from both a me3.82 and me5.92 1.8t ecu file. They were both slightly lower than the 2.0 coils.

Guess I should up the dwell a little to get full advantage of the 2.0 coils?

You are most likely forgetting the fact that dwell is calculated dynamically based on load, and that there is a multiplier for these tables.
At least that is how it is done on ME7. I don't know if it is the case for M3.8 or if it was introduced with ME7. I know that in M2.3 the coil dwell table is in degrees.
Of course, if you mean the 1.8T's that had the "stick" round type coils without POS's then yes, for those the dwell time is also around 2 ms.

But on those that had the POS's and the square coils, like the 2.7TT, the dwell time is much higher.


Title: Re: 2.0 coils on AEB - Dwell time
Post by: rnagy86 on October 17, 2012, 11:09:02 AM
You are most likely forgetting the fact that dwell is calculated dynamically based on load, and that there is a multiplier for these tables.
At least that is how it is done on ME7. I don't know if it is the case for M3.8 or if it was introduced with ME7. I know that in M2.3 the coil dwell table is in degrees.
Of course, if you mean the 1.8T's that had the "stick" round type coils without POS's then yes, for those the dwell time is also around 2 ms.

But on those that had the POS's and the square coils, like the 2.7TT, the dwell time is much higher.

Hey.

I am also using 2.0 coils in my 2.7TT and I would like to check this out as well. So the map that I should check is KFSZT (closing time (from RPM, V)) but the
using the full M-box definition file, KFSZT does not really look sane for me unless I am totally misunderstanding something. Can someone have a look at it
and tell me if what I see is correct? Thanks


Title: Re: 2.0 coils on AEB - Dwell time
Post by: prj on October 17, 2012, 12:39:20 PM
Try my auto-generated XDF.



Title: Re: 2.0 coils on AEB - Dwell time
Post by: RaraK on October 17, 2012, 05:22:14 PM
I posted up dwell tables for med9 a while back on vwvortex site, lemme find pictar's

(http://i146.photobucket.com/albums/r272/rarak69/KFSZT.jpg)
(http://i146.photobucket.com/albums/r272/rarak69/KFFANZ.jpg)
(http://i146.photobucket.com/albums/r272/rarak69/KFSZSUB.jpg)
(http://i146.photobucket.com/albums/r272/rarak69/TSMX.jpg)



Title: Re: 2.0 coils on AEB - Dwell time
Post by: s5fourdoor on October 17, 2012, 06:17:26 PM
Hmm, probably going to need a bit higher resolution here or the explicit tables.  This is not easily readable...


Title: Re: 2.0 coils on AEB - Dwell time
Post by: ricekikr on October 17, 2012, 11:59:11 PM
But on those that had the POS's and the square coils, like the 2.7TT, the dwell time is much higher.

My stock ones were square. Does that mean that a lot that did the tfsi/tsi/fsi upgrade have too much dwell?
(http://www.ecstuning.com/Audi-B5_A4-Quattro-1.8T/Engine/Ignition/ES2538546/#)

I think Max dwell is limited to 3.480 (address 7797 on a 3.82 file)

Please check pics below, not sure if I should add or reduce dwell.

(http://i767.photobucket.com/albums/xx314/ricekikr/UB.jpg)
(http://i767.photobucket.com/albums/xx314/ricekikr/subsequentsparks.jpg)
(http://i767.photobucket.com/albums/xx314/ricekikr/maxdwell.jpg)
(http://i767.photobucket.com/albums/xx314/ricekikr/factor.jpg)


Rarak thanks for the info data.


Title: Re: 2.0 coils on AEB - Dwell time
Post by: AudiSportB5S4 on April 17, 2014, 06:28:44 AM
I realize this is an older thread, but it seems the question was left open.. My buddy has two liter coils on his 2.7 and I noticed he has cold start misses that I am thinking could be related to this.. Is KFSZT the table I would be looking to find?


Title: Re: 2.0 coils on AEB - Dwell time
Post by: AudiSportB5S4 on April 17, 2014, 06:42:06 AM
Ug sorry. Search was too specific.. I didn't think it was the only thread talking about this.

Found this thread which answered my question(s): http://nefariousmotorsports.com/forum/index.php?topic=445.45