Need advise about Calc.VE Tuning

[Ram Air IV]

I am trying to do the Calc.VE Tuning. I discovered that it is hard to hit all the cells in the VE table. How many of the cell do I need to hit to make a accurate tune. Should I blend between the new value and the current value in the B0101. Please give me some advise about this.:confused:

[WeathermanShawn]

You have done a fairly decent job hitting the main drivable portions of the VE Table.

Filtering is important. Make sure you throw out anything more than +/- 10F over your normal ECT. Tighten up filtering any rapid throttle transients (TPS % > 1-5%/100ms.).

Drive in a normal fashion, and slowly open the throttle. Make sure you then apply the LTFTBEN corrections to the VE Table as described in the Tutorial. If you drive 'right', filtering is not as necessary. Try to stay out of overdrive gears if possible. You can disengage PE mode if you want more MAP coverage (modify PE TPS%).

You can hand-smooth the VE Table when you are convinced your data is valid. You can always post it up. I or Joecar can give you advice on 'smoothing'.

I posted both your VE Table and one of mine just to compare coverages...:)

Edit: Remember above 4000 RPM, Airflow is determined almost exclusively if not totally by the MAF. Always keep PE Mode engage at those Rpms'. It is fairly easy for the 'formula' to calculate a comparable VE Table at WOT. You will just have to apply a different technique for PE Mode fueling..Back to Actual AFR vs Commanded..

I am making it sound harder than it is. It is actually pretty easy. You are doing a good job hitting most of the cells..:)

[WeathermanShawn]

Ram Air:

Also, if you can post up your Calc._pids.txt file. I want to make sure your Engine Displacement is being calculated accurately in the formula.

Thanks..

[joecar]

Mentally/Visually extrapolate the newly calculated VE table to all the cells...

keeping in mind what the torque curve would look like at each MAP slice;

if you see a ridge (a set of adjacent cells in a row or col that all stick up or all stick down), don't smooth the ridge (it shows a trend over various values of MAP or RPM);

if you see a single spike or hole all by itself, that is a physical impossibility, so you can flatten/blend it out.

[joecar]

Looks like your old VE table was too high...

[WeathermanShawn]

Ram:

If it helps, here is an example of my current CALC VE Table. 80-90% of it is 'actual data'..hand-smoothing in some of the lowest Rpm's and along the margins. I also compared it against AUTOVE for accuracy.

Remember, we are modeling Airflow..It should look very similar to the MAF Airflow plotted on a 2-D surface..

[Ram Air IV]

Ok, there is a lot for me to learn.... :book:If I understand it right I don´t need to think about the cells above 4000 rpm since the engine uses the signal from the MAF, correct ? If I look at my VE table after I imported the value from Scan (Calc VE) the cells with new value is significant lower. Does that mean that I should reduce the value in all the cells around my new values ? I have adjusted the obvious incorrect values and then applied the smooth tool (50%) but I still think the VE table is rather rough. What is your opinion. :)

[WeathermanShawn]

The values came down a little because your LTFT's were overall about -5%. So your VE Table now reflects a more accurate airflow model.

I have attached your Tune with a hand-smoothed VE Table. Whats interesting is that your engine has a rapid jump in VE values as you get above 3200 Rpm's and 40 MAP (bigger engine?).

Take a look at it. I just blended in some areas..

[WeathermanShawn]

It is always easier on the 2nd or 3rd run to nail the VE Table down. The closer your LTFTBEN's are to zero (0), the less correction and more confidence in the results.

Above 4000 Rpm it is the MAF based on your Airflow Threshold. Remember though in PE Mode, Closed-Loop ceases along with the LTFTBEN function being active. So the actual MAF Calibration needs to compare Wideband AFR's vs Commanded (BENS)..as your narrowbands are not accurate in PE Mode.

With more data you can make the VE Table nice and pretty above 4000 Rpms. It may not be the controlling Airflow Model..but if your MAF ever fails it will use every bit of it for fueling..so I like to keep accuracy above 4000 Rpm's if possible.

Hopefully I have not confused you. Perhaps Joecar can be more succinct if needed..:grin:

[Ram Air IV]

Thank you Shawn, I will down load this file to my car and do a scan to see how the LTFT looks like. I dont think the engine is bigger. For a former carburator guy there is many new conceptions that are new for me. But belief me, I will not go back to old school engines.

[WeathermanShawn]

Good deal..

Oh and when you run the new tune, remember I did not make any actual changes to the MAF Calibration Table. If you have not done that already, just make sure you have.

You should know very quickly. Almost all your LTFTBEN's will be near 1.00 if that MAF was updated also..

I don't know what I was referring to on engine size. Must have misread something..:grin:.

Good Luck..

[Ram Air IV]

Do you mean the B5001? If so I have already adjusted that.

[WeathermanShawn]

Yes.
You are in good shape..:cheers: