Flat Shift Link Delay

Flat Shift Link Delay

Flat Shift Link Delay Table

This table is only available if Flat Shift Link Option is enabled in the Transmission Control function.



How much time between the Flat Shift Torque Reduction and/or Throttle Blip and the Transmission Control outputs changing. Which one happens first is determined by the Flat Shift Link Option. 

Configuration for a Typical Automatic Transmission



This shows a rough starting point for this table. The left axis is Transmission Control Current Shift, and the top axis is Line Pressure Control Target. If you have have a Line Pressure sensor, the Line Pressure sensor may be more useful. 
This will obviously require fine tuning using data obtained from the tuning process. 
On typical automatic transmissions, you want to determine the values for this table by logging the following channels during gear shifts: Transmission Control Current Shift, Engine RPM, and the channels which are on the Line Pressure Shifting Target table. 
Simply drive the car with gear shifts occurring under as many conditions as practical. Note that a dyno may not be the best for this. Also note, that it is best to do this after line pressures have been tuned, as changing the line pressure tuning will affect what values are required for this table. 
Open up the log and look for how long it takes after the Current Shift channel changes to when the Engine RPM begins changing. Set the Flat Shift Link Delay to that time for this gear shift and load. The Flat Shift Duration table should be set to how long it takes for the engine RPM to ramp up/down to the value it settles on in the new gear. The next part is to appropriately set the Flat Shift Retard and/or Percentage Cut tables to give the appropriate result. For a street car, the ideal is for torque at the wheels to be a smooth transition from the old gear to the new gear, to give greatest possible comfort. This also give good results in terms of preventing brief wheel-spin and reducing the amount the car gets upset during the shift. In higher powered applications, you may require bigger retards and bigger cuts in order to keep transmission component loads and wear within reasonable levels. 

Configuration for a Pneumatically Actuated Sequential Transmission

If you've got a pressure regulated pneumatic system, this table will likely have a single value in it. 
However, if you've got an un-regulated system, you would typically have the pneumatic pressure as an axis, with the flat shift link occurring earlier as the pressure increases. This takes into account the fact that at higher pressure, the solenoids will actuate faster. 

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