Tuning Shift Points and Pressures

[Kernal]

My mate and I installed a B&M shift in my car VT V6 Commodore. Box is a 4l60E.

1-2 under moderate throttle shifts nice and firm except at WOT it doesn't rev out, it shifts at 4000rpm and its a bit sluggish. Tried holding it in 1st and still shifts at 4k.
2-3 shifts at 5500 but not a firm shift.

A lot of people i spoke to said i need to tune the box to suit.

Any help on this issue would be much appreciated.

[charlay86]

Yeah, they are correct, you will need to adjust the transmission settings.
The PCM is programmed with "desired" times that it takes for the shift to occur (it also has minimum time limits to be in shift mode where the shift pressure modifiers apply). If the shift occurs faster or slower than the desired time, the PCM will attempt to 'fix' the problem by altering the internal hydraulic pressure used to apply the bands /clutches etc. and will start to learn the new adjusted pressure to use.

[The1]

The desired shift times or "Adaptive Shift" routine as it's called isn't enabled on VS up as i can see, it's based on Baro Measurements, the baro based tables in VS for example are all 0 and VS up dont use MAP. I have tested even changing all desired shift times to 0 and has made no difference in Commanded or actual force motor amps and car drives exactly the same, even monitoring adaptive shift pressure load cells and they never change.

The best way ive found for tuning an automatic is get the shift points where you want them, then setup a history table that's the same as your main pressure table, then do logging and fill in your history table with slip RPM, you will see typically with stock pressure 1-2 shift point slip RPM will peak, under 400 slip is generally considered a good slip amount, during shifting it may peak around 1000, under this is normal, over this and it's excessive, you will need more pressure then in that area or change the shift pressure scalar if the slipping is consistent with that gear change. There are other techniques to further tune the transmission using MOD times and ramp rates, it really depends how well or far you want to go. If you watch Slip RPM on the graph you will see the peak when a gear change occurs, around 1 second or less is good for a standard trans.

My current VS with 290k on the clock and originally tranny is hopeless with stock setup, but having tuned all the above shifts great and runs smooth for the km's on it.

[Holden202T]

The desired shift times or "Adaptive Shift" routine as it's called isn't enabled on VS up as i can see, it's based on Baro Measurements, the baro based tables in VS for example are all 0 and VS up dont use MAP. I have tested even changing all desired shift times to 0 and has made no difference in Commanded or actual force motor amps and car drives exactly the same, even monitoring adaptive shift pressure load cells and they never change.

have you changed the minimum shift thresholds ? i'm sure i changed them all too when i did mine.