This page serves as a table of contents to data summaries of various DQ250 DSG transmission TCU tunes.
Data contained in the linked pages reflects the shift behavior of the different vendor transmission control logic. The data consists of:
- Upshifting – The engine speed that the transmission shifts up a gear based on the accelerator pedal position. Shown for each gear change. More information about interpreting this data is on this DSG data translation page.
- Coasting downshift – Engine speed that the transmission shifts down a gear when the vehicle is coasting with the accelerator pedal position at 0%.
- Kickdown downshift – Engine speed that the transmission downshifts when the accelerator pedal position is greater that 30%. Shown for gears where data is available.
This video is an introduction to a few key aspects of DSG shift points.
Links to data for different tuners:
The following data should be recorded to develop the charts:
- Engine Speed (RPM)
- Accelerator Pedal Position (%)
- Selected Gear
Optionally the Brake Pedal Position can be logged which facilitates filtering the data.
To characterize upshift behavior the car should accelerate from being stationary or at low speed in first gear through to a shift into sixth gear.
The accelerator pedal should be held at a constant position throughout the period of acceleration.
The acceleration through the gears should be repeated for fixed accelerator pedal positions of 5, 10, 20, 30, and 40%; or close to these positions.
Beginning in sixth gear the accelerator should remain untouched as the car coasts to slow down. The transmission should downshift through every gear ending in first.
If the car cannot slow enough in second gear to downshift into first, meaning at idle engine speed the car still does not downshift into first, then light brake pedal should be applied to cause the shift into first gear.
While maintaining a steady engine speed the accelerator pedal should be rapidly depressed until the transmission shifts down to the next lower gear. The depression of the accelerator should not be mashing it to the floor (100%), but to the position needed to initiate a downshift.
This could take some trial and error as some TCU tunes do require 100% pedal position to downshift while others may downshift around 50%.
This should be repeated for several cruising engine speeds in 6th, 5th, 4th, and 3rd if possible.
It is preferable to have a data sampling rate around 20 samples per second although less can still provide useful data, but more data should be recorded to facilitate averaging of the results if a slower data sampling rate is used.
Use of data
One potential way to take advantage of the data that is collected here is to record similar data while driving the DSG in manual mode. By recording gear shift trends in manual mode the data can be compared to the various tune options to find a tune that is best suited to how the driver shifts.
For assistance with generating charts for a TCU tune that is not shown I can be contacted at: firstname.lastname@example.org