What will happen if VE tuneed with wrong IFR data ?

[wesam]

What will happen if VE tuneed with wrong IFR data ?
car is OLSD

[swingtan]

Assuming final AFR's are correct....


If the error is linear across the pressure PIDs, then you can expect that the values in the VE table will be out by a similar amount. This may result in the VE values being "higher" than expected or "lower" than expected. In a manual car, this may have little effect but may have an effect in an auto.
If the error is random through the calibration, then fueling will be very hard to get correct and AFR drifts may result.


there may be more to it than this though....

Simon

[wesam]

What do you mean by AFR drifts ?

[wesam]

and what if the error was not linear ?

[wesam]

How could i take B3701 from this injector manual
http://siemensdeka.com/specsheets/FI114991cs.jpg

[swingtan]

What do you mean by AFR drifts ?

If the IFR is all over the place, the resultant AFR will most likely be all over the place as well.


and what if the error was not linear ?

Point two above.


How could i take B3701 from this injector manual
http://siemensdeka.com/specsheets/FI114991cs.jpg

You would need to take all the data and work out how it applies to the tables in B3701.

B3701 is a 3d table of Injector delta pressure ( pressure across the injector ) and the battery voltage. So you need to create a new 3d table from the values in the link. At a guess ( and a big guess ) you can probably get away with FNPW_OFFSET and FNPW_OFFCOMP. however you'd need to understand the other data to make a better call on weather they should be used or not.

Simon

[redhardsupra]

then you will 'bake in' all the error from IFR table into a VE table. since IFR table is referenced against the MANVAC, and the VE table is referenced against RPM and MAP (a MANVAC derivative), the IFR error can be fully 'expressed' with a VE table. however, this is not a healthy habit to get into.
here's some old reading for ya: http://redhardsupra.blogspot.com/2006/12/ve-ifr-transformation.html