# VAG-COM ignition timing and retard.



## big-jona (Jun 11, 2002)

Hi,
Have a cable throttle AGU engine. Did some logging of group 024 which
on my car is:
RPM, Load (ms - whatever that is), timing (20atdc-42btdc), sum retard (0-36deg)
I have some numbers like:
RPM Load Ign Timing: Retard:
1480	1.05	-16.5	0
1480	1.05	-16.5	0
1520	1.05	-17.3	0
2560	3.4	-34.5	0
2960	6.3	-24	0
4360	7.45	-28.5	0
4200	8.6	-25.5	0
4840	2.3	-33	0
4360	9.3	-24.8	0
4600	8.9	-24	6.7
5000	8.6	-24.8	6.7
5960	7.5	-27	6.7
5920	7.5	-27.8	4.5
5000	0.75	-12	4.5
4200	9.55	-21.8	4.5
4520	9.2	-22.5	11.2
4800	8.95	-23.3	15.7
5040	8.65	-21.8	15
5240	8.35	-25.5	12
5440	8.15	-25.5	6.7
5680	7.85	-26.3	5.2
5880	7.65	-24.8	5.2
6080	7.45	-26.3	8.2
6360	7.05	-27.8	1.5
What do the ignition timing numbers mean? I saw some other posts with numbers
nothing like these.
Also, the sum retard (I think knock control will retard timing 0 - 9 deg on
each cylinder hence 0 - 36deg total) - When this number goes above 0 is 
this when my ECU is pulling timing because of knock control???
Any help/advice would be great. Thanks.
Jon


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## Speedy G (Apr 1, 2002)

*Re: VAG-COM ignition timing and retard. (big-jona)*

Those numbers look like mine, I have an AGU as well and see 24 deg often. I've been wondering about this as well. What is atdc and what is btdc? The retard angle is already in the mid 20's does this mean we don't have much room for higher boost? I know Billy T was getting 32deg retard with a ton more boost.
Btw, what fuel grade were you running?
I'd love to hear more about this as well.
Speedy G


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## Speedy G (Apr 1, 2002)

*Re: VAG-COM ignition timing and retard. (big-jona)*

I really need to know.
Speedy G


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## Andrew Stauffer (Oct 2, 2000)

*Re: VAG-COM ignition timing and retard. (big-jona)*

There is a mailing list, set up by the VAG TEC creator, Use Ross. They discuss issues like this all day long, infact the answers to your questions are probably(most certainly) in the archives of that mailing list. You can link to the mailing list via the vag com website. I'll warn you, it gets a bit.....dry. Seems like the overly technical crew there can spend 3 weeks discussing things that I have a hard time knowing if it's even related to a car. Invariably, it is, computer issues, but well, take a look, you'll see what I mean. The info is there, and it's *good*, but there's alot to wade through....


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## big-jona (Jun 11, 2002)

*Re: VAG-COM ignition timing and retard. (Speedy G)*

Yeah I NEED to know too.
I was runing Optimax (98 RON) when those numbers were taken. The highest
MAF reading I saw was like 144g/s as well. What numbers do you run SpeedyG??
I am starting to come to the conclusion that the AGU is a POS, especially with
the K03 hairdryer. I am cranking my boostvalve right up and hoping the thing
blows up or something then I get an S3. Hhhmmmmmmm S3.
I have also put the stock airbox back on but I haven't done any logging yet.
When I get my new clutch I thnk I will have it dynoed, the stupid POS is really
starting to bug me now...
Cheers,
Jon


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## 9VW23yrs (Jun 22, 2000)

*Re: VAG-COM ignition timing and retard. (big-jona)*

From what I have seen VW used (-)neg values to denote BTDC in DB cable and positive numbers on DB Wire Cars. It's a bit confusing but why they changed is a big Q.


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## scotty_passat (Apr 17, 2001)

*Re: VAG-COM ignition timing and retard. (9VW23yrs)*

do a fixed gear WOT run up the rpm range, you must be getting off/on the gas which will cause timing to advance/retard.
you should see approx 8-12 DBTDC at idle, reatarding close to 0-5 DBTDC when the boost kicks in (2000-3000 rpm), then ramping (advancing) back up to ~20-24 DBTDC as rpms rise to redline.
from what i've seen, chipping will advance the idle, light load timing (this is your fuel economy increase) increase the retard at the boost onset point (to reduce tip-in knock), and result in a higher advance point at upper rpms under load (high octane required).
here's a plot of a chipped car on a cold day:








under light load or throttle overrun advance gets very high. optimum angle is something like 34 DBTDC assuming there is no knock.
i've seen the difference between dbw and non dbw, seems correct about the polarity.


[Modified by scotty_passat, 7:05 AM 2-5-2003]


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## big-jona (Jun 11, 2002)

*Re: VAG-COM ignition timing and retard. (scotty_passat)*

Thanks for the post Scotty.
So you think my numbers for timing look OK even though they are -ve??
Running about -24 deg with some retard (I think highest average is 4 deg per
cylinder) is OK?
I was worried about my fuel trim because of the timing (I think AGU has
crappy injectors alhough it, apparently, has larger intake ports than the
newer engines but no VCT). 
I thought car wasn't running right becuase the max g/s I see is about 144
which is, I think, too low for a car which is chipped with boostvalve and
2.5inch turboback (including 100 cell sports cat). Although it only has the
poxy K03. My N75 duty cycle was all at 99 most of the time during the
figures I posted - too much boost?
Also, wtf is load??? (is it simply an rpm vs throttle position map or is
it actually measuring something??) what are the units (ms)?)
Cheers anyway guys,
Jon



[Modified by big-jona, 4:31 PM 2-5-2003]


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## scotty_passat (Apr 17, 2001)

*Re: VAG-COM ignition timing and retard. (big-jona)*

well i don't know much about AGU but if it has the AEB type K03 you will get 99% N75 duty cycle at high rpms. If anything your timing looks quite advanced but it's load dependant.
Try the 3rd gear idle-redline WOT run, log block 3. block 20 and 21 will give you any knock related correction values, each cylinder needs to be less than 12 degrees of knock retard.
the plot was from an AWW with an UP chip @ 30 degrees F FYI.


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## scotty_passat (Apr 17, 2001)

*Re: VAG-COM ignition timing and retard. (scotty_passat)*

not sure if load is a valid parameter on cable cars.


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## big-jona (Jun 11, 2002)

*Re: VAG-COM ignition timing and retard. (scotty_passat)*






















http://****************.com/smile/emthup.gif


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## Speedy G (Apr 1, 2002)

*Re: VAG-COM ignition timing and retard. (big-jona)*

Something else to think about... The 144g/s is not bad actually, I have 120g/s, but I'm at 2600m altitude. I have a theory that AGU MAFs are different from the US AWD MAFs and our numbers are slightly lower. The ETKA name for them is actually "Air Flow Meter" for the AGU and "Air Volume meter" for the other engine codes (AUQ is like US AWP). Also about AGU, if you prefer paying for out of the box HP, get that S3, otherwise the AGU engine is the best for high HP mods in the 1.8t lineup. We have no DBW, no ASR, no VVT, which all get in the way of some serious HP.
BTW thanks guys for the timing info. The VAG-COM Yahoo! group also says nothing interesting about this stuff. I'm still wondering what ATDC and BTDC stand for btw.
Speedy G


[Modified by Speedy G, 4:58 PM 2-5-2003]


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## [email protected] (Jun 5, 2002)

*Re: VAG-COM ignition timing and retard. (Speedy G)*

quote:[HR][/HR] I'm still wondering what ATDC and BTDC stand for btw.[HR][/HR]​ATDC = After Top Dead Center
BTDC = Before Top Dead Center
MAF's give a signal to the ECU that is converted to g/s of airflow. It doesn't matter where in the world you are, what elevation, etc. g/s of air is g/s of air.


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## big-jona (Jun 11, 2002)

*Re: VAG-COM ignition timing and retard. ([email protected])*

After you posted that relationship the other day
between whp and g/s I nearly cried








The best I got with the Viper was 144g/s - need to do a run now
I have the stock airbox back in. The cars feels pretty quick though,
it will do 146mph (on the autobahn







) and it did 0-60 in 7.6
before it was chipped, it must be at least a second quicker
now.....


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## [email protected] (Jun 5, 2002)

*Re: VAG-COM ignition timing and retard. (big-jona)*

If the MAF is failing (giving incorrect data) that relationship wouldn't hold true. In general, a chipped 1.8T should see at least 160 g/s. Do a Butt Dyno:
http://forums.vwvortex.com/zerothread?id=521365


[Modified by [email protected], 12:25 PM 2-5-2003]


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## Speedy G (Apr 1, 2002)

*Re: VAG-COM ignition timing and retard. ([email protected])*

Yeah, I know g/s should be g/s, but it doesn't make sense that my car feels so much quicker than my mom's MX6 (160hp) at 120g/s. My car also has 3000km so it's hard to believe the MAF is bad, and it runs like it did when I first chipped it (1000km). I'll have to go to the dyno to see what's really going on. I don't know much about VAG-COM, but does the possibility exists that the VAG-COM tables are bad for AGU?
Speedy G


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## big-jona (Jun 11, 2002)

*Re: VAG-COM ignition timing and retard. (Speedy G)*

I figured that two. I logged the injector timing group (2 or 3
can't remember) and it seemd to max out at 16.32ms - wasn't sure if
this was the maximum (which in the a/f xls showed I was running about
17:1 - boom!) or just the upper limit on the vag-com group. How
wide are the data bits in the frame?
Basically, VAG-COM sucks for AGU








Will just have to dyno I guess...


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## Speedy G (Apr 1, 2002)

*Re: VAG-COM ignition timing and retard. (big-jona)*

John_s described the protocol somewhere, but I forgot where. Maybe in the serial programming thread. About VAG-COM, I've also noticed some numbers outside of the "normal" range at the top of the csv file. It could be a simple bug of the ECU, or in VAG-COM. Either is possible, since AGU's aren't too accessible in the States, and bugs live everywhere.
Speedy G


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## scotty_passat (Apr 17, 2001)

*Re: VAG-COM ignition timing and retard. ([email protected])*

quote:[HR][/HR] I'm still wondering what ATDC and BTDC stand for btw.
ATDC = After Top Dead Center
BTDC = Before Top Dead Center
MAF's give a signal to the ECU that is converted to g/s of airflow. It doesn't matter where in the world you are, what elevation, etc. g/s of air is g/s of air.[HR][/HR]​i'd think that at high elevation the thinner air would limit the mass of air you can stuff in...ie a car that pulls 160 g/s at sea level will be less at high altitude...assuming they both run the same boost pressure.


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## RR (Jan 22, 2003)

*Re: VAG-COM ignition timing and retard. (scotty_passat)*

I think Scotty's observations are spot-on. I live at 6000ft and can't get more than 120-125 gm/s out of the AEB on my Passat.


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## [email protected] (Jun 5, 2002)

*Re: VAG-COM ignition timing and retard. (scotty_passat)*

quote:[HR][/HR] I'm still wondering what ATDC and BTDC stand for btw.
ATDC = After Top Dead Center
BTDC = Before Top Dead Center
MAF's give a signal to the ECU that is converted to g/s of airflow. It doesn't matter where in the world you are, what elevation, etc. g/s of air is g/s of air.
i'd think that at high elevation the thinner air would limit the mass of air you can stuff in...ie a car that pulls 160 g/s at sea level will be less at high altitude...assuming they both run the same boost pressure. [HR][/HR]​I completely agree, but the MAF doesn't care about your elevation, or the density of the air. All it cares about is how many molecules of air smack against the hot wire per second. So, if the MAF is in good working order, it will deliver accurate airflow readings in Death Valley and at the top of Pike's Peak. 
big-jona wrote:
quote:[HR][/HR] Basically, VAG-COM sucks for AGU







[HR][/HR]​Please explain why it is VAG-COM's fault that your ECU doesn't have as many sensors as the DBW cars.


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## scotty_passat (Apr 17, 2001)

*Re: VAG-COM ignition timing and retard. ([email protected])*

quote:[HR][/HR] I completely agree, but the MAF doesn't care about your elevation, or the density of the air. All it cares about is how many molecules of air smack against the hot wire per second. So, if the MAF is in good working order, it will deliver accurate airflow readings in Death Valley and at the top of Pike's Peak. [HR][/HR]​agreed!








OT ahve you seen the latest edition of grassroots motorsports magazine, big article on the mini


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## [email protected] (Jun 5, 2002)

*Re: VAG-COM ignition timing and retard. (scotty_passat)*

Oh yeah! I got a subscription for X-mas.


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## big-jona (Jun 11, 2002)

*Re: VAG-COM ignition timing and retard. ([email protected])*

quote:[HR][/HR] 
Please explain why it is VAG-COM's fault that your ECU doesn't have as many sensors as the DBW cars.







[HR][/HR]​Hmmm, I didnt say VAG-COM sucks, I said it sucks for AGU - which it does.
I have AGU and VAG-COM which I think entitles me to say what I think on
a forum 
Thanks.
Jon


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## [email protected] (Jun 5, 2002)

*Re: VAG-COM ignition timing and retard. (big-jona)*

I understand that, I just wanted to know why you felt the way you do.


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## big-jona (Jun 11, 2002)

*Re: VAG-COM ignition timing and retard. ([email protected])*

Cool http://****************.com/smile/emthup.gif 
It's really only usefule for clearing DTC's. I suppose I should
have qualified it better by saying it's not much use for logging.
BTW, I am doing my best to understand what information it does
give and trying to make it useful (i.e. getting boost from MAF,
understanding the timing stuff - the subject of this post etc.)
No disrepect to the actual product intended.
Cheers,
Jon


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## [email protected] (Jun 5, 2002)

*Re: VAG-COM ignition timing and retard. (big-jona)*

Have you checked erWin for engine diagnostics documentation?
http://erwin.volkswagen.de/index.jsp
What version of Motronic is your ECU? In the US, cable-throttle 1.8T's were typically Motronic 5.x.


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## Speedy G (Apr 1, 2002)

*Re: VAG-COM ignition timing and retard. ([email protected])*

Nah, ours are Motronic 3.5 or something. I have etka, erwin and bentley, but only the etka is AGU specific. I also have an Octavia specific book, which has also been helpful, but isn't in as much detail as the Bentley. BTW, I love that AGU has less electronics, it makes our engines much more upgradeable. I also love my VAG-COM, just yesterday I cleared an airbag code the dealer forgot to clear after some interior work (they're pretty dense here). The point is we need more info regarding this engine, and it's hard to come by, since not enough people outside the US use this board. 
In any case, the MAF question can only be answered by a dyno and a VAG-COM. Regarding boost, I'm starting to install my AVC-R today along with some other minor mods, so I'll take some readings. I also wanted to take some readings of the O2 sensor voltage vs. calculated a/f, but I'm changing laptops due to a broken mouse.
My theory is that maybe our MAFs are callibrated to be more accurate in the lower rpms, and the Max value doesn't matter. One thing about sensors is that not only you need to know what voltager/unit of measurement you're talking about, but also in what range they're accurate. I'm thinking we have the cheap 50 buck sensors and not the expensive new ones you guys get in the US.
BTW that AEB... is that chipped at 120g/s?
Speedy G


[Modified by Speedy G, 4:23 PM 2-6-2003]


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## Speedy G (Apr 1, 2002)

*Re: VAG-COM ignition timing and retard. (Speedy G)*

Also, I think we just need more time to get the right spreadsheets together for an AGU engine. With the correct calculations we can get good guesstimates on a/f, boost, HP (and therefore torque), ignition timing, etc. The only other useful data in tuning is EGT's, and that's why I'm putting a sensor it. Again, I love VAG-COM since it cost me as much as my EGT gauge (peak and hold), but it logs many different variables TOGETHER!!! Give me a month, and we'll have all that calculated data.
Speedy G


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