Change up speed in a Auto

[microcat36]

Can someone tell me what determines when an auto gearbox will change up, is it speed, revs or pressure of the fluid in the gearbox.
The reason I ask is the max revs that the box will change at is about 5,600 rpm in kick down in any gear, which is great in any 4 cyl Saab engine as this is about where the 4 cyl produces its max power , but in the V6 the max power is at 6,200 rpm, so the auto changes well short of the max rev's for this engine so you don’t get the full 215 bhp, you have to use the lock out in any gear to get to the full rpm, so can the max speed/revs that the gearbox changes up at be altered in any way. :-??

[boxman]

the shift pionts in the auto tranny are determined by two things, road speed and throttle position :! the kick down cable that is connected to the throttle lever tells the hydrolic curcuits in the tranny how hard you are accelarating so you could try adjusting the cable a little but don't go mad it might, and probably is a result of the engine not producing the right amount of power for the given throttle opening i.e. engine power may be abit low

boxman

[microcat36]

That’s the worst of there not being that many 9000 v6 , none around to compare with, tried to find a road test that might give me max speed/revs in the specs but no luck ether, might try giving a dealer a phone on the off chance they might tell me.