I ran two tests using my HP Tuner with stock transmission pressure and an increase of 3% on the second test.

Notice on the 1-2 shift in the charts below how quickly the rpm drops verses the 2-3. Looks like a lot of slippage on the 2-3. Stock pressure for the 1-2 is greter than the 2-3. The last group was with the pressure 3% higher across the board. The rpm drops quicker indicating less slippage.

I'm not sure how much slippage is acceptable but I like the last chart better. If I'm counting right the 3% pressure increase reduced the slippage two frames verses stock pressure. 4 frames verses 6 when you start counting on gear 3 shift. Note in red.

(TP is throttle position)

MPH RPM TP Gear

25 4170 100 1
29 4804 100 1
32 5095 100 1
37 5313 100 1
40 5658 100 1
43 5992 100 1
47 6317 100 2
50 5929 100 2
53 5033 100 2
58 5032 100 2
58 5111 100 2
61 5185 100 2
63 5254 100 2
65 5323 100 2
67 5388 100 2
70 5454 100 2
71 5551 100 2
74 5663 100 2
75 5740 100 2
77 5846 100 2
79 5956 100 2
81 6025 100 2
83 6141 100 3
85 6220 100 3
86 6328 100 3
87 6406 100 3
88 6486 100 3
91 5979 100 3
91 5181 100 3
93 5142 100 3
94 5167 100 3
95 5194 100 3
94 5111 0 3


+3% pressure
53 2425 13 3
53 2429 13 3
53 2410 13 3
53 2425 14 3
53 2446 14 3
53 2435 14 3
53 2439 16 3
55 3072 100 2
57 4473 100 2
58 5189 100 2
62 5270 100 2
63 5322 100 2
65 5368 100 2
68 5420 100 2
70 5481 100 2
71 5581 100 2
74 5674 100 2
75 5772 100 2
77 5865 100 2
79 5958 100 2
81 6052 100 2
83 6144 100 3
84 6228 100 3
85 6280 100 3
88 5768 100 3
88 5154 100 3
90 5122 100 3
91 5154 100 3
93 5171 100 3
92 5062 0 3
91 3613 0 3

 

I prefer to use the Table display, delete a few things and add 'time of latest 1-2 shift'
and 'time of latest 2-3 shift'
It will give you the time it took to complete the shift. IMO it should not be more than your 'desired shift time' for that shift.
If it is, first I'd lower the desired shift time, if that doesn't help I'd mess with the upshift pressure modifiers.

 

Good point! Looks like I need another log.