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View Full Version : Shift Times, Line Pressures, Adaptive Learning -- AGAIN!



arubenstein
July 16th, 2008, 11:00 AM
I've been searching around, and know this has been hashed and rehashed. I wanted to clarify something.

In my situation, I have a '08 Suburban 6.0 L76, and a 4L70E. The 4L70E has been 'fully built', as they say (see list below).

For the moment, the motor is stock (except for a Gibson exhaust, and a dyno tune). RWHP is up maybe 20 hp from stock (this is temporary, magnacharger en route)

So, if I am reading everything correctly, the general consensus is as follows... When you have a built transmission, you should:

a) return all settings (torque managment, line pressures, etc) to stock. Just a good idea because it is a baseline to work from.

b) change shift times to 0 (D1101, D2101, D3101, D1102, D2102, D3102). Do this because the TCM will not be able to understand what is happening when it commands a particular line pressure, and the shift happens way faster than it think it should.

Now, drive the vehicle. Make your own assessments as to whether or not shifts are too firm, too mushy, or whatever.

In my case, I immediately removed all torque management on upshifts (is it safe to do on downshifts?). Things are way, way too harsh. Like, i feel like I am going to break my seat off the rails even at 50% TPS. So, this is where I am not sure what to do:

Should I decrease line pressure until I get the shift feel I like?

Should I increase torque management until I get the shift feel I like?

One before the other? Only one, or the other?

If life were perfect, I'd have a nearly perfectly smooth shift, with no TM.

Then, when the 6 psi magnacharger goes in, then what?

Any help appreciated.


Vigalante triple disc 2500 stall
sleeved input drum
beast shell kit w/bearing
GM 5 pinion input carrier
GM 5 pinion reaction carrier
Bearing style reaction shaft
New reverse input drum
Alto wide 2-4 carbon lined band with reinforced anchor
8 B/W hi-energy clutches w/koleen steels in 3-4 clutch
B/W 29 element sprag
4L70E low roller clutch
Transgo HD-2 shift kit
Sonnex Servos
Bushing kit
New solenoids
B/W clutches
Updated aluminum accumulator pistons

arubenstein
July 16th, 2008, 11:09 AM
And should D8001, Pressure Pattern 1 Adapts Option be disabled?

Wouldn't doing that mitigate the need to setting 0's in all the shift time tables?