4l80 torque conv not unlocking on acceleration in top

[ZAPPA]

Hey guys,
Have completed the swap of the ls1 and 4l80 into my Aussie nissan patrol. Everything works well. I just have a couple of questions, hopefully someone can help with.
Being that my nissan weighs in a a tad over 3t. At highway speeds when overtaking the conv will not unlock unless it obviously changes down to 3rd. All the tunes I've checked allow unlocking in to at 100% tow which by then I'm nearly back to second. The extra 300 odd revs that the unlocking will get me a lil higher in the torque band of the ls without changing to 3rd. I've already spaced the 4-3 and 3-2 because you would put the foot down to acc and eventually push far enough that it will change back to second!
Is there any reason I can't adjust so the conv unlocks before the 4-3 down change?
Thought there May be a mech reason why they don't want it to?
Cheers in advance
Karl

[joecar]

Hi Karl,

Post your tune file...

[ZAPPA]

ls1 4l80 current base tune conv changes_mk2 unlock.ctz
cheers for taking the time to look at it joecar. i have made a few changes. dont be alarmed at the setup of the gearbox, i had to machine 10 grooves into an adaptor shaft to get my speed sensor operational. its within 2km/h!

[joecar]

Several things:

Throttle Kickdown:
set these to 100% (they will interfere with PT up/down shifts.

PT up/down shift:
curves cross; they should not cross each other (and they should be separated).

TCC apply/release curves:
these cross (or overlap) each other; they should not cross (and they should be separated);
the TCC apply/release curves for a particular gear should be within the operating range of that gear (i.e. between the PT up/down shift curves that result in that gear).

Use the spreadsheet to see what I mean.

[joecar]

Like this:

PT shift table relationships:

basic relationships:
1->2 curve should be above 2->1 curve;
2->3 curve should be above 3->2 curve;
3->4 curve should be above 4->3 curve;
. . .

additional relationships:
3->2 curve should be above 1->2 curve;
4->3 curve should be above 2->3 curve;
. . .

this can be summarized as: the curves cannot cross anywhere;

if they cross anywhere, then you will not be able to predict what gear the TCM selects when the operating point hits the cross.

[ZAPPA]

Thanks mate
,I'll have a play, it's hard to get the whole idea of each gear without having 10 screens up at once! That might explain the lil flair I get on the 3-4 shift if the conv is engaged.