Stratified Automotive Controls has been making some refinements to their DSG TCU tune based on feedback that I have given. Previously I discussed the first round of modifications to the tune and recently I received a second update with more changes.
Updates to the tune have a heavy emphasis on part throttle response as this is the operating range that is most common during daily driving. By way of datalogging during regular daily driving and aggregating the results of Accelerator Pedal Position (APP) for each of the gears a trend is developed, as shown on the histogram below, the trend is used as the basis for establishing the targeted engine upshift RPM versus APP input.
This revision to the TCU tune shows the following improvements:
- Upshift from 1st to 2nd continues to be improved. The minimum upshift engine speed has been raised as well as the full range of engine upshift RPM across the range of accelerator pedal input identified for improvement – i.e. part throttle range.
- Upshift from 2nd to 3rd improves on moderately heavy APP input raising engine upshift RPM versus the previous revision.
- Upshift from 3rd to 4th also increases engine upshift RPM at moderate APP.
- Upshift from 4th to 5th also changes as with 3rd to 4th.
- Upshift from 5th to 6th has an increase in the minimum upshift engine speed at low APP.
- Forced downshift from 6th to 5th and 5th to 4th takes place with less APP.
Changes with this revision have moved the transmission response characteristics closer to the goal values. The results have been provided back to Stratified to be used for guiding the next update.