Couple of basic Auto VE issues for guidance?

[Bruce Melton]

I have been around her since the beginning but just now being dragged kicking and screaming into Auto VE for bigger cam and displacement.

Two questions after intitial logging.

Started with stock 6.0 VE table which worked decent with MAFtune but now>
I cannot sustain anything near idle either before initial log or after first cut.
I suspect it is way too rich to hold any idle so I must diddle the throttle above ~1600rpm to keep it running. AFR is about 10 in the range below 1600. Can I just put in some guesstimate #s in that lower range to catch an idle so that Auto VE can work on it? ( I revived my old MAF tune for a sanity check and it idles ok)
The tuning abouve 1600 seems to be leveling out fine.

Can I or should I just use my new derived B0101 valves in the backup (2000 OS) B0103 or is there some good reason why those tables should be different?

Thanks always,
Bruce

[dfe1]

I switched to SD Custom OS3 on my 01 C5 with minimal mods, just to get a feel for the changes necessary, and even with a stock displacement engine/stock cam combination, idle calibration was way off, just switching from MAF to SD. I could never get Auto VE to give me the results I wanted, so I worked with wide band AFR data and made changes manually based on the logged data. But before I could get that far, I had to completely rework the VE table just to get a place to start. The VE tables for MAF and SD tunes look like they're for two different vehicles. Don't worry about what should be-- just give the engine what it wants and you should be able to establish a reasonable baseline fairly easily. Also, if you haven't already, jack up the ETC Predicted Airflow table (C6101) to avoid setting P1514 and a dead gas pedal.

[Bruce Melton]

I just give the engine what it wants and you should be able to establish a reasonable baseline fairly easily. Also, if you haven't already, jack up the ETC Predicted Airflow table (C6101) to avoid setting P1514 and a dead gas pedal.
Thanks, I got 1514 from the start so that is fixed.
I will try to guess what it wants to baseline. Reaaly surprised the perscribed VE values are totally unrunable.

[TAQuickness]

If you are using a 98-00 OEM OS, you need to apply the changes to both the primary and back up VE tables. When in SD, for these OS's, the PCM is running off the back up VE table. The changes to the back up will effect your next drive, and the changes to the primary are setting the path for you to return to MAF operation and or upgrade to a more friendly OS.


Thanks, I got 1514 from the start so that is fixed.
I will try to guess what it wants to baseline. Reaaly surprised the perscribed VE values are totally unrunable.

Shouldn't be that shocking. The tutorial was written for a broad audience. On one end of the spectrum, there are folks such as yourself that wisely inquire to the why and proceed with caution. On the other end, there are folks that have not a clue as to what an Air Fuel Ratio is or how to avoid dangerously lean conditions.

Perhaps if you took row 400-1600 and reduced the values by 5% increments (reduce, flash, reduce, flash, reduce, flash) that will get you idling again and able to fine tune.

[Bruce Melton]

If you are using a 98-00 OEM OS, you need to apply the changes to both the primary and back up VE tables. When in SD, for these OS's, the PCM is running off the back up VE table. The changes to the back up will effect your next drive, and the changes to the primary are setting the path for you to return to MAF operation and or upgrade to a more friendly OS.



Shouldn't be that shocking. The tutorial was written for a broad audience. On one end of the spectrum, there are folks such as yourself that wisely inquire to the why and proceed with caution. On the other end, there are folks that have not a clue as to what an Air Fuel Ratio is or how to avoid dangerously lean conditions.

Perhaps if you took row 400-1600 and reduced the values by 5% increments (reduce, flash, reduce, flash, reduce, flash) that will get you idling again and able to fine tune.

The tutorial sets up 2 BEN MAPS one for primary and one for backup. The stock VE tables are similiar for Primary and Backup. Is it reasonable to use the AutoTuned Primary results for backup?
I should update OS but waiting for V2 I guess.

[TAQuickness]

The tutorial sets up 2 BEN MAPS one for primary and one for backup. The stock VE tables are similiar for Primary and Backup. Is it reasonable to use the AutoTuned Primary results for backup?
I should update OS but waiting for V2 I guess.

You could do a copy paste with labels from the primary to secondary. But, teh resolution of the tables is different. I believe the primary is in 5 kPa increments while the back up is in 10 kPa increments.

Prior to upgrading to an 02 OS, I had noticed minor differences in BEN's between the two maps.

If you have any interest in upgrading your OS, I would do it now, to an 02 OS. Makes the initial VE tuning easier (no back up VE table), and opens up a lot of nice options in the custom OS segment. OS5 is bad to the bone.

[Bruce Melton]

You could do a copy paste with labels from the primary to secondary. But, teh resolution of the tables is different. I believe the primary is in 5 kPa increments while the back up is in 10 kPa increments.

Prior to upgrading to an 02 OS, I had noticed minor differences in BEN's between the two maps.

If you have any interest in upgrading your OS, I would do it now, to an 02 OS. Makes the initial VE tuning easier (no back up VE table), and opens up a lot of nice options in the custom OS segment. OS5 is bad to the bone.

I am just a "Personal" guy so it is hard to upgrade my station in life. ;-)

[dfe1]

I am just a "Personal" guy so it is hard to upgrade my station in life. ;-) The price of an upgrade is really insignificant compared to the time you'll spend beating your head against the wall and cost of the head bandages. Besides, one thing about beating your head against the wall- it feels really good when you stop.

[TAQuickness]

I am just a "Personal" guy so it is hard to upgrade my station in life. ;-)

That's no problem. The tutorial was written while tuning my '00 bird on a stock OS.


The price of an upgrade is really insignificant compared to the time you'll spend beating your head against the wall and cost of the head bandages. Besides, one thing about beating your head against the wall- it feels really good when you stop.

I really like that.

[Bruce Melton]

BTW it is working. I have it idling and logging with increasing success. Another 10 sessions and I should be good to go.
Gas milage is really increasing as I get leaner.
First log was brutal, 1/3 tank in ~20 min. I guess 8x52#@~10AFR is a big pipe. My eyes, neighbors and the vegetation in my yard will never be the same. No cats and the feline is staggering too.
Sorry Al G.

[TAQuickness]

BTW it is working. I have it idling and logging with increasing success. Another 10 sessions and I should be good to go.
Gas milage is really increasing as I get leaner.
First log was brutal, 1/3 tank in ~20 min. I guess 8x52#@~10AFR is a big pipe. My eyes, neighbors and the vegetation in my yard will never be the same. No cats and the feline is staggering too.
Sorry Al G.


Good to hear. I recall being rather embarassed the on the first drive. things lined out really fast though.

[MSGHUFF]

Bruce,
I'm in the process of tuning my 402 also and I tried and tried but was getting frustrated with trying to update both ve tables and couldn’t seem to get it right. So I upgraded to commercial and changed my OS to an 02 ZO6. It’s a lot easier and for the first time I was able to dial in my VE table tonight. I have a long way to go still, but so far I am glad I don’t have to wrestle with that damn backup table!! Less than 4k I was able to get all 1's tonight and have a smooth idle at 800rpms. Tomorrow I will enable the o2's and see if my trims agree and start to figure the MAF out. If you would like to see what I have so far I can send you my tune if you’re curious what worked for me. If I remember correctly we are close as far as mods go. -Wayne

[Bruce Melton]

Wayne,
The VE is coming along now, albeit slowly.
Sent you an email,
Bruce