Delayed 1-2 WOT shift

[LBSBLOWN]

This is a 2001 Suburban with a supercharger.
I have disabled TM and my mid throttle shifts are great, but at WOT
my 1-2 shift starts and delays or slips for 200 rpm then shifts firm.
2-3 shifts are great at WOT.
I have my shift times set at .150 sec's.
if I enable the TM then it shifts instantly but it pulls timing and falls on its face just before the shift.
anybody else run in to this and come up with a fix.

[jimmyblue]

Might try enabling the TM but limiting its authority, set the table in
Engine>Spark Retard>Max KR vs RPM ("Max Spark Retard Limit vs
RPM) to something like:

10 10 10 10 10 10 12 14 16 18 20 20 20 20 20 20 20 20 20 20 20


This table is really misnamed from the way it seems to work, the value
is the lowest advance that any of the retard functions (incl TM) can pull
you down to. This will give you a setup where you have -some- TM in,
but it can't kill your output like the stock -10 degrees pull-to limit would.

I don't know why the shift should hang, but suspect it might be something
to do with high load value, high line pressure and needing to bleed down
for the disengage before the engage can be applied. Maybe the TM cut
gives you a head start on this (torque calc -> line pressure, more line in
means longer bleed-out) etc. - whether real or "imagined" by the PCM.
I know some shift-kits specifically try to address the bleed-time with you
drilling out certain orifices etc.

[rattle]

1-2 shift in a 4l60-e (or any 700r-4 variant) does not release anything, only applys the 2-4 band. Most likely what is happening is there is severe slippage while the band is trying to grab hold of the outside of the reverse input drum.
You will want to have MORE line pressure for a WOT 1-2 shift.

You may also want to look into putting lighter springs in the accumulators(or even remove the springs), Drilling larger holes in the spacer plate will also get more fluid into the servo quicker.

first look at your BAse shift pressures and Upshift pressure modifiers as well as the temperature modifier

[LBSBLOWN]

1-2 shift in a 4l60-e (or any 700r-4 variant) does not release anything, only applys the 2-4 band. Most likely what is happening is there is severe slippage while the band is trying to grab hold of the outside of the reverse input drum.
You will want to have MORE line pressure for a WOT 1-2 shift.

first look at your BAse shift pressures and Upshift pressure modifiers as well as the temperature modifier

Thanks Rattle,
I'll give this a try and post the results.