e38 ve tunning

[lstruck]

First off I need to vent E38 SUCK!


Every time i try to smooth 2 things happen.
1. i click gen coeff and it looks okay then ge vve and it goes flat
2. I click gen coeff and it looks okay then ge vve and it looks good then I save and the damn thing goes flat again.


What gives before I set this car on fire lol.

[swingtan]

Just remember that changes to the VVE are not directly applied "as is" to the co-efficients. All changes made to the VVE will automatically be averaged across all cells in the VVE zone when the co-efficients are generated. Further "smoothing" occurs when the co-efficients are used to generate the VVE again. So a tips for this are....


Ensure that the VVE zones are set correctly for your application. The VVE zones can only curve in a convex or concave shape, you can't have a "wave" in a zone. IE. the zone can only change shape once along any axis (RPM or MAP). Set the zone boundaries so they occur at peaks or troughs within the VVE.
Any spikes in the VVE that are significantly different from the rest of the VVE are highly suspicious and likely to be erroneous data. The nature of the VVE means that any changes within a zone are averaged across all cells in the zone, so significant spikes in a single cell will automatically be averaged out.
When gathering data for correcting the VVE, the more data you have the better the result will be. You will want at least 30 minutes of "road based logs" at normal operating temps, 2 hours will give a much better result. If you are dyno tuning, you can use significantly less data as the conditions can be controlled better. In both cases, gentle throttle use is needed.
Finally, don;t expect to get is spot on in a single try. Multiple passes will be needed and even then, some manual adjust may be needed to help out. Remember that the cell adjustments are averaged across the zone, you may want to try over correcting some adjustments to allow for the averaging effect.


The VVE is a different mind set to the classical static VE table. The benefit of it is that once it's set correctly, it can compensate for minor changes and keep fueling correct, especially if you want to use camshaft phasing...

If you're still having issues, post you tune and log data and indicate what you're trying to achieve.

Simon.