Martini, using your timing log- Got VAG LOG q's

[rxrep]

Using Ryan's +5 degrees spreadsheet as I don't have blocks 003 and 032 on mine.
Can someone explain to me what to look for in the Ignition Timing BTDC column and also the Lambda columns on the far right?

http://spreadsheets.google.com/pub?k...RF53BFLYzlDCXw

I've found out tonight that Unitronics lets me advance in .75 increments. I ran car at +4.5 and then at +5.25. It was at 3.75 over the summer, and last winter I had it up to +6, but I was only reading CF's as a measurement in 2nd through 5th gear pulls.
The +5.25 seems to pull harder than the +4.5, but I couldn't get a long enough strait section of road near my house to wind it out. I managed to log one 3rd gear 020 block 3k to 6200K RPM WOT under full load. But the cops are all over the place tonight because of the local high school football game.
My highest CF was a 4, with 0's until about 4K then mostly 2.3's from there with a 6 in cylinder one and a 6 in cylinder 4.
I want to do some logging tomorrow and I'll post, but I want to know what I'm looking for as "ideal" in the BTDC and Lambda columns so I can tweak before I post logs.
Basically, I want to know what besides CF in the logs am I looking for to estimate the most aggressive yet safe (for a non-built bottom end) timing advance? What is the best "mix" of BTDC, CF, and Lambda?

[actlsub9]

Just keep going up with with the timing until you get CF's. As to how far you go after that is your choice. Some like to keep CF's at zero, some push it to 2, 3, 4, 5... Martini has decent timing with low CF's

As for lambda, I don't know what is up with his log in your post, but check out his other two logs for lambda values...

Base
http://spreadsheets.google.com/pub?k...RF6Q3uYpjaGXPg

+3
http://spreadsheets.google.com/pub?k...RF6Q3uYpjaGXPg

[rxrep]

Thanks Greg. Still hoping for an explanation on what the BTDC and lambda numbers tell me.
I'm not too concerned with CF's that show occasional 5 or 6 at WOT under full load. But I want to make sure my BTDC and lambda are ideal based on those CF's. I'm guessing lambda should read 6.4 and 0.8, but what is that actually telling me? And what am I looking for in BTDC?

[Trev]

^.....Correct me if im wrong but both those logs like exactly the same...?

[actlsub9]

Thanks Greg. Still hoping for an explanation on what the BTDC and lambda numbers tell me.
I'm not too concerned with CF's that show occasional 5 or 6 at WOT under full load. But I want to make sure my BTDC and lambda are ideal based on those CF's. I'm guessing lambda should read 6.4 and 0.8, but what is that actually telling me? And what am I looking for in BTDC?

Your want to know what the actual numbers mean? Your lambda is used to calculate you air/fuel ratio. Higher lambda is more lean, lower is more rich. Your BTDC is just telling you how many degrees your timing is advanced. The higher the number, the closer to TDC your piston will be when the combustion hits it.

[HTA A4]

CF's look good. About what temp. was this pull made?

EDIT: I log my 031 block for lambda. How do you figure A/F ratio with the Lambda %?

And you're timing BTDC looks really good for what CF's you're getting. I've never been able to run that much advance.

[actlsub9]

CF's look good. About what temp. was this pull made?

EDIT: I log my 031 block for lambda. How do you figure A/F ratio with the Lambda %?

And you're timing BTDC looks really good for what CF's you're getting. I've never been able to run that much advance.

Those are not his logs, they are martini's.

Lambda 1 is 14.7:1 A/F at sea level.

[HTA A4]

Those are not his logs, they are martini's.

Lambda 1 is 14.7:1 A/F at sea level.

Ah I see. I just used block 031 Lambda Control and multiplied the given decimal number by 14.7. But Greg, what would you say about that timing with those CF's? To me, it seems like he's running a good amount of timing advance with minimal CFs.

[actlsub9]

But Greg, what would you say about that timing with those CF's? To me, it seems like he's running a good amount of timing advance with minimal CFs.

Yep, as I said in my first post, the timing on martini's logs looked good.

[HTA A4]

Just keep going up with with the timing until you get CF's. As to how far you go after that is your choice. Some like to keep CF's at zero, some push it to 2, 3, 4, 5... Martini has decent timing with low CF's

Yeah, and there it is. Sorry about that lol

[F16HTON]

Lee, if you look at the log you posted regarding Lambda, it is block 032 which is the Lambda correction factor it is a percentage that the ECU has to correct based upong the injector size, the first valure on the left is at idle, the right is long term fuel trims...those two values look good as they are well within the range that the ECU can correct.

If you want to know what your air/fuel ratio is in respect to the O2 sensor readings with the VAG-COM, the log block 031 which will give you the Lambda value, this number can be multiplied by 14.7 to get the A/F ration as in respect to the O2 sensor.

[rxrep]

Thanks to the Gregs.
So, the layman's version is that I want a combination of the highest BTDC with the lowest lambda, and CF's of my choosing (which for me is some spikes to 5-6 for short period is OK but I try to keep 0's with 2-3 max).

[F16HTON]

That is how I prefer things to be...

My reasoning is that when logging, typically you only get a chance to do maybe 20 seconds of a pull before you run out of road, or about to lose you license and get you car towed.

Sure, you can crank the timing up but all you are doing is kill the top end power if you see CFs in the 10-12 range. (add six degrees of timing, only to see 10 degrees get pulled back, your net gain is -4 degrees.)

Lemmiwinks or the uni version just add a voltage offset to your timing map, the voltage offset shifts the whole curve up.

I am sure if you get much more agressive with the timing, you may squeak a couple of more ponies out, however I prefer to keep my motor in one piece, it has stayed that way for four years now, being punished on a regular basis.