Best way to make shifts "softer" and more luxury-like

I have a 2012 Chevy Impala with a 3.6L LFX engine (300hp) and a 6T70 6-speed transmission. I've never really been a fan of the way the 6-speed transmission shifts - I like shifts to be as smooth and unnoticeable as possible. I realize that most folks like to "firm up" the shifts for better performance, but I'm not concerned with performance and I'm interested in the most effective and safest way to make the shifts as "comfortable" as possible (like a luxury car would feel, such as a Cadillac). Again, performance is a non-factor for me - I've maybe did 5 WOT's since I bought the car over a year and a half ago - and even then I only did it on the highway during high-speeds, just to see what she had (I never do WOT from a stop and never really *needed* to go WOT). I couldn't care less about how fast I can get from 0-60mph and would never even think about racing in my 4-door family car. :-)

I'm VERY new to tuning (first car I've ever even considered customizing, mainly due to the way the transmission shifts). Stock low-speed shifting is absolutely horrible (clunky, jerky and "un-refined"). I did purchase a mail-order tune because everyone was saying how much "better" it shifted with this tune, but I quickly realized that "better" means different things to different people. For my preferences, I feel that it made the shifting even worse (much firmer and less "comfortable" than stock).

So, I'm curious as to the most effective and safest way to make the shifts smoother and more comfortable. Not sure if I should be increasing the shift times, lowering shift pressures, increasing the amount of torque management or a combination of all of the above.

So far, I've disabled neutral skip-shifts, disabled TCC lockup in 1st-4th gears and slightly modified some torque management settings. Between the mail-order engine tune (which makes the throttle feel much better and more "natural") and the transmission-related changes mentioned above, I'm much happier with the way the car shifts now. But, since I purchased an HPTuner device to apply the mailorder tune anyway, I want to see if I can use it further to make the shifting even more "comfortable".

I've attached my stock tune file here. Since my current "active" tune contains engine-related changes from a commercial mailorder tune, I can't post it, but I've combined the transmission-related changes from my current tune with the stock engine tune and posted that as well (so you can see what transmission-related changes I've made so far).

Thank you in advance for any advice you can offer! I'm really enjoying my HPTuner device and love being able to customize things to my liking - just need to learn a lot more! :-)

Or - should I just try lowering some of the "Shift Inertia Factor Profile" numbers - and let the computer adjust shift timing and pressures itself, based on the lower inertia factor profile numbers?

I wish I had a read from a new-style Impala or a newer 6-speed Buick to compare it to (since, in my experience, Buicks tend to shift very "softly").

Anyone happen to have a read from a newer 6-speed Buick (LaCrosse, for example) or a newer Cadillac? I've tried looking at some stock tunes for Cadillacs, but since they are rear-wheel-drive, I'm not sure if I can safely "compare" most of the transmission values or not. That and most of the non-sport Cadillacs are older and have 4-speed transmissions.

Anyone out there that can give me some advice on this? I know that I could just try changing the shift time, shift pressure and/or shift intertia factor profiles and see what happens, but I'm really looking for some advice from the "pros" as to the best and safest way to acheive my goals of "softer" shifts.

Strangely, I thought that the "shift intertia factor profile" numbers (1-9) would go from hgihest value (1) to lowest value (9), but if you look at the stock tune I posted above, that's not the case. 5 actually has the highest value (.4004)! So kinda confused about those values now...

Can anyone help this noob? :-)

Thanks in advance.

Your goals of "softer" shifts will likely induce slip; which hurts durability and fuel mileage.
Most of us here want the opposite; a crisp, fast shift.

I would leave the desired shift times and pressures stock to avoid slip, and disable the TCC in lower gears (which you have done).
The biggest thing I would tweak would be torque management.
Adjusting "shift inertia factor profile" has an effect on shift times, pressures, and TM. I think it would be better for you to adjust individual parameters in your situation.

For a smooth shift you'll want the torque management to ramp in and ramp off.

Also maybe drive another Impala and get a comparison, just to make sure the problem isn't mechanical. (Shift quality degrades as the hardparts wear)

First off - thank you VERY much for the reply! Not many people in here, so I appreciate all of the help I can get (otherwise, I have to learn by trial and error, which could end up being expensive)!

I can live with reduced transmission life if needed (if we're talking about a difference of 120k or 100k, for example). It would be worth it to me to have a car I enjoy driving.

That being said, I'm all for trying to adjust torque management instead. I have read a lot about that and I think I know where to start in that respect.

One more strange thing I've found. The 2012+ W-body Impalas with the 6T70 seem to have a "clunk" when reapplying the throttle after coasting (at low speeds). By logging, I've pretty much found that it only seems to happen when reapplying the gas in 3rd gear - somethies in 4th. I've been able to pretty much eliminate this clunk by lowering some of the Shift Intertia Factor Profiles in the 3-4 shift and 4-5 shift tables (at lower RPMs and torque). What I don't understand is why changing shift values would affect this clunk since there isn't any actual shifting going on when it happens (just reapplying the throttle in the current gear). Is this because I'm actually increasing the amount of torque management (as well as shift time and shift pressures) in general by lowing the shift inertia factor profile values - even when the transmission is not actually shifting? I don't see any way to modify these values other than for actual gear changes though...

Also - any tips on the best way to modify the torque management to suit my needs - would it be via the Shift Torque Factor Adder and Shift Torque Factor Adder Modifier tables?

Again - than you VERY much for the response!!

Actually, the more that I think about the "clunk" issue when reapplying the throttle after coasting, I realize that I really want to increase the amount of torque management on the engine side, since the transmission isn't even shifting at that point... So my next question is how would I do that? I really only want to increase the amount of engine torque management between say 10-30mph and only during "tip-in".

I notice that there is a "Tip-in Enable" table, but it only enabled or disabled - how do I control the amount of engine torque management being applied during tip-in (tip-in torque management is already enabled in the table) - not quite sure where I would "tune" that...

Thanks!

i lowered my upshift shift pressures by -.5 and seemed to calm mine down for my downshift clunk i lowered my downshift speeds a few mph it was like it was lugging the engine im using tires that are too big for my rear gears but i was getting firm shifts like too firm my truck is only a 99 so im limited to what i have to edit but im sure you have trans upshift pressures and aslong as you only take out like .5 yes it wont be as firm but with mine i had to move everything so i know it might not be as good for it my shift speeds are moved down to around .300 so i know my trans isn't hanging around in gear when it could of been shifted.