'09 Silverado "Firm" Shift question

[mattf301]

I loaded the 87 Octane tune, AFM off, Firm Shift. I have about 40 miles on the tune. It shifts a bit harshly from 1-2. Will this smooth out after some more miles? What can I do to smooth it out if it doesn't? Also What does shutting off TCM do differently then just setting it to "Firm"?

[mjj]

I'm not positive on this but possibly modifying the tcm tune and decreasing the shift pressure from 1-2 might soften that harshness up. But I'm curious what the suggested method is. Do we pick the firm or hard shift tune then modify the pressure from there or do we not pick firm or hard and then just modify the tcm shift pressure for each gear shift if we want it increased some but not too harsh? What is the equivalent pressure settings (1-20) of the firm and hard preset ones? And say if I choose firm then modify the pressure is picking +3 adding to the already set value of the firm setting or am I effectively or possibly negating out the values from the firm preset? I've probably made this confusing sorry. Hopefully one of the Diabo guys will chime in on this.
Also, do you mean turning torque management off and not tcm. From my understanding torque management reduces engine power to the transmission during shifts to increase the longevity of the drivetrain but then your performance suffers some. I read a lot of people prefer it off and have not had any issues with it off. So not exactly sure what the overall risk vs reward of doing this is.

[mattf301]

That's what I need to know. What exactly do I do to soften the 1-2 shift?

[MagnaPilot]

I have an '09 Silverado as well, with the 4L60E transmission, and had the same issue. I never got a clear answer as to why the "firm" tcm option was excessively harsh, but I did manage to smooth it out almost entirely while keeping it sportier than stock. The Firm and Hard shift tunes feel like they're going to remove my rear end and transmission if I were to drive it long that way. Not to mention my wife refused to drive it like that. Perhaps with two of us DiabloSport will chime in and explain.

My settings are below:

ECM: Standard 87 Octane Tune
TCM: Modify Stock Tune

1>2 Part Throttle Shift Pres. = +10%
1>2 WOT Shift Pres. = +20%
2>3 Part Throttle Shift Pres. = +15%
2>3 WOT Shift Pres. = +20%
3>4 Part Throttle Shift Pres. = +5%
3>4 WOT Shift Pres. = Stock


Edit: I just noticed my Torque management settings didn't post. Give me a little while, I'll post those as well (again).

[mattf301]

It's only my 1-2 that shifts too hard. 2-4 are smooth. Just want to smooth 1-2 out a bit.

[MagnaPilot]

Here is the rest, I put all of these settings in the "Normal" TCM tune, I left the Sport/Tow stock.

1>2 Torque Reduction = -10%
2>3 Torque Reduction = -10%
3>4 Torque Reduction = -7%

DiabloSport! Why does the "Firm" Shift tune want to remove our transmissions on these trucks?

[MagnaPilot]

Just curious, how has your MPGs been with AFM off?

[mjj]

Here is the rest, I put all of these settings in the "Normal" TCM tune, I left the Sport/Tow stock.

1>2 Torque Reduction = -10%
2>3 Torque Reduction = -10%
3>4 Torque Reduction = -7%

DiabloSport! Why does the "Firm" Shift tune want to remove our transmissions on these trucks?

Where do you find the torque reduction settings? I only see an option for torque management on or off. Maybe since I have a 2014 its different.

[mattf301]

Magnapilot-did you turn off torque management before putting in these settings?

[MagnaPilot]

I did not, no. I don't think the 4L60 tranny is stout enough to be running without Torque management daily in a truck. Using those settings, I just reduced it.

It was on the second page after the shift pressure settings, but if yours does not have it, I'd imagine they haven't updated the inTune to be able to change it yet. There may be a global setting for it as well, but I've never had to mess with it, as I prefer to keep it turned on, and so does my wife (her truck technically).

[6.2Allterrain]

subscribed