Calc VE QC check and questions

[Strong05]

Hi All!

I'm new to the forum and tuning. I've been reading up on everything for a while and have just starting tuning my 2000 T/A. Just wanted someone to take a look at my Calc VE table to ensure I'm not doing anything stupid.

Also had a couple of questions concerning the Calc VE tuning process:

1. Should I be looking to fill every cell with data to remap the entire VE table or just below 4k rpm (the VE/MAF blend rpm threshold I believe)?

2. The Calc VE tuturial doesn't really address the use of a wideband (LC-1 in my case). What should be done differently when using a wideband vs just relying on the narrow O2's?

3. It seems to me that you would be better off calibrating the MAF with the wideband before you should try this method, otherwise wouldn't you be skewing the data with a MAF that isn't dialed in?

Sorry if any of these questions are way off base... still trying to get a handle on all the new terminology and tuning in general.

Thanks for all the help!

Brad

[WeathermanShawn]

Brad:

Welcome to the Forum..

You want to primarily hit the below 4000 RPM area as that will be the area that normally your MAF/VE blend area is. However, I always tell people to hit the higher RPM/MAP areas. The reason is that your MAF can fail (more common than people realize) and then your VE Table will control all airflow/fuel calculations.

Just make sure you filter (rapid throttle) as much as possible. Some hand-smoothing is actually desirable. It has to make sense from an airflow perspective.

This method utilizes closed loop which takes your MAF Airflow, IAT, ECT, RPM, MAP and LTFTBEN correction to determine the CALC.VE Value. Hence, in the closed-loop portion you do not need to 'calibrate' your MAF with a wideband. In closed-loop the stoich AFR is always being determined by the variance in the LTFTBEN.

The wideband is utilized when you hit PE Mode and WOT. Then you are leaving closed-loop and entering open-loop fueling. There you will utilizing an AFRBEN (variance from commanded AFR). That PID is well-described in numerous threads and in the AUTOVE Tutorial..

Many people have accomplished the CALC. VE Table Tutorial. So far it is the only tuning method that allows simultaneous tuning of the MAF, VE Table, and LTFT's. It makes the most sense for people who will utilize closed-loop and still retain the MAF.

Good luck..

[Strong05]

Shawn,

Thanks for the quick response!

Keeping in mind that this method is for closed loop only; how do you get the higher rpms/MAP areas without going into open loop? For that matter how can the few cells that I have filled in the higher area be accurate? Doesn't the system come off closed loop at a certain TPS threshold? Therefore shouldn't any data recorded in open loop be void?

Thanks again for you help, and hopefully I'm not beating a dead horse... I tried to read up on this is much as possible in your original CALC VE thread.

Brad

[joecar]

Hi Brad,

Welcome to the forum

Log FUELSYS, use this to see where it goes OL and use this to filter out OL data.

The Calc VE tutorial does two things using LTFT's: calculates a new VE table, and corrects the existing MAF table.

[WeathermanShawn]

Brad:

Also, be aware that even though you are in open-loop at the higher RPMs/MAP the CALC.VE Table formula still 'works'. It is taking your MAF Frequency, RPM, MAP, ECT, IAT, etc.

The following is a MAP that is filtering just PE Mode. I am mapping the Serial Wideband Ben Factor. The second chart shows the same data with LTFTBEN's applied. So in open-loop your LTFTBEN will go to 1.00. Obviously that value is only accurate when your open-loop commanded AFR matches actual (BEN Factor).

Probably just best that you log and map Table B5001. That one needs to be accurate. Then post your results. It will be easier to explain once you have a more extensive mapping of your MAF vs LTFTBEN.

[Strong05]

Alright, I did another data log and logged the FUELSYS parameter this time. How do I use the filter to filter out the OL stuff? If you select the parameter it only lets you put in numerical values for the less than or equal to box, when its a text field under the data tab. I also had a weird value for this parameter of CL-fault, not sure what that means, but it still cycled to OL.

I think it might be important to mention that I have also updated the OS to a 2002 OS (got if off of holden crazy) from the factory 2000 OS. I did this because I was eventually planning on using the custom OS's and wanted to take little steps (I think one of the tutorials said you can't use the 2000 tunes on the custom OS's). Hopefully that wasn't a dumb idea. I did update the injector tables (hopefully all the correct ones).

Thanks again for you help!

[Strong05]

Brad:

Also, be aware that even though you are in open-loop at the higher RPMs/MAP the CALC.VE Table formula still 'works'. It is taking your MAF Frequency, RPM, MAP, ECT, IAT, etc.

The following is a MAP that is filtering just PE Mode. I am mapping the Serial Wideband Ben Factor. The second chart shows the same data with LTFTBEN's applied. So in open-loop your LTFTBEN will go to 1.00. Obviously that value is only accurate when your open-loop commanded AFR matches actual (BEN Factor).

Probably just best that you log and map Table B5001. That one needs to be accurate. Then post your results. It will be easier to explain once you have a more extensive mapping of your MAF vs LTFTBEN.

So your saying it will still calculate the VE table but without the narrow band correction factor correct? And that it will ignore any OL data for the MAF calibration stuff? So it's more important to calibrate the MAF frequency table before trying to get the VE table filled?

I attached my last run.

Sorry if I'm stuck on some of the simple stuff here...

[WeathermanShawn]

So your saying it will still calculate the VE table but without the narrow band correction factor correct?

That is not correct. Look at the formula in my signature. The last multiplier is "CALC.LTFTBEN". When you go from closed-loop to open-loop the PCM 'freezes' your LTFTBEN. If it is negative it goes to 1.00 (no correction). If it is positive it will be added. As I state in the Tutorial your goal is to always have negative or at least a 1.00 LTFTBEN.

And that it will ignore any OL data for the MAF calibration stuff?

That is also not correct. See explanation above..

So it's more important to calibrate the MAF frequency table before trying to get the VE table filled?

The beauty of the system is that it is computing both simultaneously. You CANNOT have an accurate VE Table without an accurate MAF Calibration Table.

I attached my last run.

Sorry if I'm stuck on some of the simple stuff here...

The best approach when you feel like the 'simple stuff' is hanging you up is just do the procedure as the Tutorial instructs. The information on filtering is also found in numerous EFILive threads. The best way to get specialized help is to post your completed Log and Tables..and then ask for someone to review it.

Remember, get your MAF Calibration vs LTFTBEN Values as close to 1.00 as possible and apply all the applicable filters.

Hope that helps..

[WeathermanShawn]

Also, can you do another log with the narrowband PIDS attached (per Tutorial). You may have to drop some other PIDS to keep the channel count under 24.

You have numerous DTC's relating to your O2's. Are you sure they are attached? Your vehicle is going into CL-Fault (not closed-loop) because of this..

[Strong05]

Everything emissions related has been deleted. I have disabled the corresponding parameters that set off the CIL. Edit: I disabled them after the above attached run.

Thanks,
Brad