NefMoto

Noob Zone => Noob Questions => Topic started by: Basano on April 12, 2015, 12:25:52 PM



Title: Timing Oscillations
Post by: Basano on April 12, 2015, 12:25:52 PM
Since I am a noob at tuning, I’m a bit puzzled about this one.

(http://nefariousmotorsports.com/forum/index.php?action=dlattach;topic=8110.0;attach=13389;image)

Some kind of intervention?

Audi S3 8P MY2008
2.0 TFSI MED9.1
8P0907115H
387951

Hardware is completely stock, tune is pretty basic stage 1 that I’ve been putting together myself (with help from all of you thanks :) )

I’ve logged some other variables as well for what it’s worth (assuming things are somewhat similar between ME7 and MED9.1) since there’s been a huge amount of work put into this on ME7. Bear in mind, it's a WOT scenario though.

(http://nefariousmotorsports.com/forum/index.php?action=dlattach;topic=8110.0;attach=13391;image)

(http://nefariousmotorsports.com/forum/index.php?action=dlattach;topic=8110.0;attach=13393;image)


Title: Re: Timing Oscillations
Post by: technic on April 12, 2015, 12:49:00 PM
What is VCDS block 020 showing? Looks like CF.


Title: Re: Timing Oscillations
Post by: Basano on April 12, 2015, 01:15:52 PM
CF's are very mild.

0 degrees correction on three cylinders and -3.75 on the fourth.

I've superimposed them here.

I'm wondering why zwout zig-zags around so rapidly even though the CF remains at a steady -3.75? Then around 6250 rpm, the oscillation in zwout dies down and still CF on that one cylinder is a steady -3.75

(http://nefariousmotorsports.com/forum/index.php?action=dlattach;topic=8110.0;attach=13395;image)


Title: Re: Timing Oscillations
Post by: ddillenger on April 12, 2015, 04:45:32 PM
Timing will always look like that during KR.


Title: Re: Timing Oscillations
Post by: vwaudiguy on April 12, 2015, 04:51:01 PM
KR = Timing correction while knocking (timing pull in at least 1 cylinder)?


Title: Re: Timing Oscillations
Post by: prj on April 12, 2015, 04:55:52 PM
I'm wondering why zwout zig-zags around so rapidly even though the CF remains at a steady -3.75? Then around 6250 rpm, the oscillation in zwout dies down and still CF on that one cylinder is a steady -3.75

Because zwout is the current output timing after correction.
So if you have 3.75 CF on one cylinder, then due to the sample rate it will randomly jump to 3.75 and back.
If you had some special per-cylinder logging, the germans call it "Synchroraster", then you would see a pattern of 3 1 3 1 3 1 and so on, but since your logger is just best effort fixed in time, you see random jumps.


Title: Re: Timing Oscillations
Post by: Basano on April 13, 2015, 12:13:14 AM
I have learnt something new today.

Thank you.