Originally Posted by
SlowNStock
You can increase Base Line Pressure ("Transmission -> Shift Pressures -> General") for the gears you want to firm up/decrease shift time. Make conservative changes, say 5% or less at a time, focus on the higher throttle positions (say 30-40% TPS or above), blend it into the lower TPS cells, and leave the maximum values alone (which should match PCS Line Max, and should also be left alone).
You can try to work with torque management ("Transmission -> Torque Management"), emphasizing higher torque and RPM areas. Try to reduce 5-10% at a time to get a little firmer shift, and make these changes separately from pressure changes. Again, don't go too far here, just enough to firm up the shifts to your liking; whiz bang shifts might feel quick, but often aren't (and are sometimes actually slower). Part of what makes the transmissions you reference shift so well is well-tuned torque management.
There's lots of bad advice out there for transmissions - deleting torque management, scaling the entire pressure table an arbitrary amount, cranking up max pressures, etc. - the reality is the OEMs don't leave lots "on the table", and it's difficult to gauge the net mechanical effect of our tuning changes (a firmer shift may decrease clutch wear, but increase shock loads, more line pressure may increase temps from additional friction or it may decrease from reduced slip, etc.). The name of the game is conservative changes, making iterations, and not straying too far from the baseline - without good reason, I wouldn't go beyond 10-15% additional pressure or 20-25% less torque management.