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View Full Version : What filters do you use on your scans?



pauly24
June 27th, 2010, 02:52 PM
Just curious if its a good idea to use filters on the scans, like remove all data where the throttle is changed very quickly or something like that?

If so what filters do you use and on what scans do you use them?

Thanks.

joecar
June 27th, 2010, 05:35 PM
You filter out throttle and airflow transition on logs that are to be used directly for modifying tables.

pauly24
June 27th, 2010, 05:59 PM
Yes that is where im getting at, say I log a AFR BEN corrected map.

So throttle would be the change in TPs, what value do you use, 5% change in 50ms?

How do you filter out airflow transition?

joecar
June 28th, 2010, 02:28 AM
For TP I use more than 5% change in 100ms as comes in the BEN TP filter.

For airflow/airmass, I have been playing with MAF or DYNAIR changing more than 5 g/s or 10 g/s in 50ms or 100ms (you can enter a value regardless of the up/down arrow buttons)... I see that airflow transitions usually coincide with TP transitions (i.e. so TP transition filter might be sufficient)... it's a matter of playing with the filter and looking at the data that remains, any sharp changes in the original data should be removed, and what remains is data whose conditions more closely meet steady state conditions (when eyeballing a filtered waveform, any sharp transitions now seen are not really there because this is the data that remains after filtering).

Also, don't forget to exclude operating points such as low ECT, DFCO, low TP, low RPM, excessive AFR.