The shift points can be changed to increase performance by extending the shift points out a little further. On many GM trucks the 1-2 shift is 5400 RPM and the 2-3 at 5200. Taking them out to 5500 to 5600 RPM can really help the truck pull thru the top end a little better and end up in a nice part of the torque curve after the shift has completed. On the shift firmness, this is done to improve the quickness and feel of the shifts to provide a better feeling shift and actually reduce tranny wear by creating less heat and friction that you would have with a longer drawn out shift. Also, the downshifts can be made much more agressive so you don't get that dead feeling when you pull out to pass someone and kick it down and get that 3-4 seconds of delayed reaction and then the sudden downshift when it almost seems too late.What's the advantage to changing the shift points/firmness? I'm getting ready to buy the hypertech max energy programmer and I know you can adjust those too, but being a non-techy, I don't know why'd I want to do it.
Before the advent of the electronic trans everything was controlled via the valve body and tweaks to it.I copied this from the Hypertech wbsite so I hope this helps.
In addition to controlling engine functions such as air/fuel mixture, spark timing, and maximum rpm, these highly evolved ECUs also regulate transmission shift points and firmness, limit top speed, and display speedometer and odometer readings. Hypertech engineers were able to use these capabilities to provide additional features for enthusiasts. The Power Programmer is much more than a tuning chip * it is a self-contained automotive tuning computer. The Power Programmer automatically installs the powerful Hypertech tuning program. It also allows enthusiasts to access and reprogram the vehicle’s computer to function properly with aftermarket components such as non-stock wheels, tires, and rearend ratios. A Hypertech Power Programmer is really the most powerful and versatile tool a performance enthusiast can own!