Reading the 1.3 help files and suddenly saw the light on one of the torque converter issues I have.
TCC Lock During Shift...
By the name I assumed it meant lock the TCC during shifts. (Which I thought odd, but lets not go there.) Reading the updated help file however I find it actually determines if the TCC will remain locked during a shift. Ahhhh....
Makes sense of my logged data.
Does anyone know the ramifications to the torque converter and transmission of leaving the converter locked during shifts?
At the moment I have a problem at some throttle positions with the converter locking in 3rd, very soon after the transmission shifts to 4th and the TC unlocks, then almost immediately locks again. I can increase the TC apply points in 3rd for those throttle positions so that it doesn't lock before shifting to 4th. Playing around so far, it seems to throw other aspects of the transmission's behaviour out. (i.e., it isn't quite that simple...)
So now I could also change the Lock During Shift setting so that it doesn't unlock at shifts. (Smooth things out.) I can see that would introduce a problem by itself however. I guess the TCC Lock During Shift setting also effects downshifts - where you tend to want the TC to unlock. I assume by default, 2nd gear lock and release is set at 367km/h across the board. This means 2nd does not lock... but also... does not release either.
(So I assume if I kick down from 3-2 at anything less than 100%TPS (what my release %TPS vs Speed tables hold), I'll be stuck in 2nd with TC locked....)
Is there any particular reason 2nd gear TC release isn't (or can't) be set at 1... or some other low number?