Desired Shift Times

[ferocity02]

How does the PCM compute the shift times for shifts?

I set my desired shift times to 0.3s for all gears and logged the shift times. Average shift time was 0.12s for 1-2, 0.22s for 2-3, and 0.77s for 3-4.

How long does it take for the trans to "adapt" to better hit these shift times?

What does it adjust to better hit these shift times?

It's a 4L80E with an HD2 shift kit. I've heard that with a shift kit it's harder for the trans to learn and adapt to the shifts, so many people recommend setting the desired shift times to zero.


Log is attached.

[Chevy366]

With my Transgo kit I had to revert back to stock shift times otherwise it was way to harsh of a shift, of course I did "normal" on the hole size in the plate, I shot peened the holes and went back to "soft" hole size, still will shift with a good bump.
If you zero them out it will bang hard and fast mine would chirp the rear from first to second, felt like someone was running into the rear of the truck.
The kits are designed to enhance the stock trans with no adjustments needed, so keep it with stock shift times (actually all trans parameters), if you want harder/faster shifts use the holes in the plate (drill to largest size bit Transgo sent with the kit) to achieve that.

[ferocity02]

With my Transgo kit I had to revert back to stock shift times otherwise it was way to harsh of a shift, of course I did "normal" on the hole size in the plate, I shot peened the holes and went back to "soft" hole size, still will shift with a good bump.
If you zero them out it will bang hard and fast mine would chirp the rear from first to second, felt like someone was running into the rear of the truck.
The kits are designed to enhance the stock trans with no adjustments needed, so keep it with stock shift times (actually all trans parameters), if you want harder/faster shifts use the holes in the plate (drill to largest size bit Transgo sent with the kit) to achieve that.

Thanks for the info. I drilled all of mine to "average" I think. With stock tune settings the 1-2 is overly firm/jerky, not tire chirping though. And 2-3 and 3-4 feel like butter. Since I did the internal dual feed mod, I think I need to drill out the 2-3 hole a little more since there is now more space to fill in the direct.

I'm having other issues as well, such as no TCC lockup unless my line pressure is over 150psi, then it will lock.

I was just curious what "shift time" actually means. It does not appear to be the time from when the shift was commanded to when the RPM's drop.

When I got from stock to zero desired shift times I don't really notice and change in shift firmness.

[Chevy366]

Thanks for the info. I drilled all of mine to "average" I think. With stock tune settings the 1-2 is overly firm/jerky, not tire chirping though. And 2-3 and 3-4 feel like butter. Since I did the internal dual feed mod, I think I need to drill out the 2-3 hole a little more since there is now more space to fill in the direct.

I'm having other issues as well, such as no TCC lockup unless my line pressure is over 150psi, then it will lock.

I was just curious what "shift time" actually means. It does not appear to be the time from when the shift was commanded to when the RPM's drop.

When I got from stock to zero desired shift times I don't really notice and change in shift firmness.

Here is a good read -- http://coloradofans.com/forums/67-technical-questions-tips-how/102108-4l60-e-transmission-adaptive-functions-explained.html
It is for a 4L60E but it still applies.
And here -- http://forum.efilive.com/showthread.php?1723-How-about-a-transmission-tuning-tutorial!&highlight=shift+time (http://forum.efilive.com/showthread.php?1723-How-about-a-transmission-tuning-tutorial%21&highlight=shift+time)

Did you do the kit yourself?

[ScarabEpic22]

I believe the Transgo HD2 changes TCC lockup into an On/Off style vs PWM, what are your TCC lockup % tables set to? Id set the low to 95% and high to 98-100%. See if that resolves your TCC lockup issue.

The PCM will use the Desired shit time table as a target, if they arent matching that then you need to play with line pressures a bit (small adjustments, dont want to overwork the pump!). Id start by setting the trans settings back to 100% stock and see what happens.

[ferocity02]

Here is a good read -- http://coloradofans.com/forums/67-technical-questions-tips-how/102108-4l60-e-transmission-adaptive-functions-explained.html
It is for a 4L60E but it still applies.

Did you do the kit yourself?

Good link. Yes I built the trans myself.



I believe the Transgo HD2 changes TCC lockup into an On/Off style vs PWM, what are your TCC lockup % tables set to? Id set the low to 95% and high to 98-100%. See if that resolves your TCC lockup issue.

The PCM will use the Desired shit time table as a target, if they arent matching that then you need to play with line pressures a bit (small adjustments, dont want to overwork the pump!). Id start by setting the trans settings back to 100% stock and see what happens.

I set the min PWM table to 90% and the max to 99%, didn't help the issue. If I manually ground the TCC solenoid at light throttle nothing happens. As I increase throttle, the line pressure rises and once it gets to about 150psi the TCC applies, but not quite fully, still slips several hundred RPMs. This morning I drove it with max line pressure which gives me about 180psi all the time and the TCC will engage and hold with zero slip.

It's a strange issue, definitely needs to dig into the trans again.

[Chevy366]

I believe the Transgo HD2 changes TCC lockup into an On/Off style vs PWM, what are your TCC lockup % tables set to? Id set the low to 95% and high to 98-100%. See if that resolves your TCC lockup issue.

The PCM will use the Desired shit time table as a target, if they arent matching that then you need to play with line pressures a bit (small adjustments, dont want to overwork the pump!). Id start by setting the trans settings back to 100% stock and see what happens.

Really Erik, didn't on mine.
Don't go raising line pressures the Transgo kit should have done that for you if you installed the correct springs (until you figure out if something is wrong or not), a correct install of the Transgo kit will yield a faster firmer shift.

[Chevy366]

Good link. Yes I built the trans myself.




I set the min PWM table to 90% and the max to 99%, didn't help the issue. If I manually ground the TCC solenoid at light throttle nothing happens. As I increase throttle, the line pressure rises and once it gets to about 150psi the TCC applies, but not quite fully, still slips several hundred RPMs. This morning I drove it with max line pressure which gives me about 180psi all the time and the TCC will engage and hold with zero slip.

It's a strange issue, definitely needs to dig into the trans again.

How did the soft aluminum plugs fit into the plate holes they block off, I had one that was not to secure and had to make one that fit tighter. Might want to take a look at the plate again and make sure nothing has moved and that all springs are correct.

[ferocity02]

What plugs are you referring to?

[Chevy366]

What plugs are you referring to?

There are two small aluminum plugs that you insert into the steel section plate and hammer down flush to block off 2 passages.

[ferocity02]

There are two small aluminum plugs that you insert into the steel section plate and hammer down flush to block off 2 passages.

My HD-2 kit didn't have me do that.

http://www.performancetrucks.net/forums/gm-drivetrain-suspension-22/transgo-4l80e-hd2-instructions-please-507451/

[Chevy366]

My HD-2 kit didn't have me do that.

http://www.performancetrucks.net/forums/gm-drivetrain-suspension-22/transgo-4l80e-hd2-instructions-please-507451/

Cool, got a plate with yours, if you followed the directions correctly you should have a nice shifting trans.
If you notice there are a few springs that increase pressures.
Mine came with a manual plate for manual shifts, so a little different kit.
Notice there a couple of things that are different, I had to replace a spring in the trans upper left corner, I don't see it in yours.
Am looking for my instruction sheets I will post once I find, but I don't think it will help you seeing you have a kit different than the one I got.

[ferocity02]

Cool, got a plate with yours, if you followed the directions correctly you should have a nice shifting trans.
If you notice there are a few springs that increase pressures.
Mine came with a manual plate for manual shifts, so a little different kit.
Notice there a couple of things that are different, I had to replace a spring in the trans upper left corner, I don't see it in yours.
Am looking for my instruction sheets I will post once I find, but I don't think it will help you seeing you have a kit different than the one I got.

I did not follow the HD2 kit instructions 100%. I left out their 3-layer plate because it has the potential for cross-leaks. I did the dual feed mods internally to the trans and use a stock separator plate that I drilled out for the shift firmness. I also didn't use its pressure relief valve or boost valve, I used the Sonnax self-regulating boost valve instead.

[Chevy366]

I did not follow the HD2 kit instructions 100%. I left out their 3-layer plate because it has the potential for cross-leaks. I did the dual feed mods internally to the trans and use a stock separator plate that I drilled out for the shift firmness. I also didn't use its pressure relief valve or boost valve, I used the Sonnax self-regulating boost valve instead.
Might be why you are having problems then.
I don't know anything about all that voodoo stuff you mentioned, because I did the install by the directions and mine worked flawlessly.
Maybe someone will see this and have done something close to what you have done and help out, can't help with off standard builds.

[ferocity02]

Might be why you are having problems then.
I don't know anything about all that voodoo stuff you mentioned, because I did the install by the directions and mine worked flawlessly.
Maybe someone will see this and have done something close to what you have done and help out, can't help with off standard builds.

The internal dual feed is a very common way of dual feeding the direct, it's what the pro's do, common practice on the 80E and TH400.

Basically all I used from the HD2 kit was the springs and the other misc valve body mods. I am considering removing all of the HD2 kit when I dig into the valve body, not sure yet.

[ScarabEpic22]

Really Erik, didn't on mine.
Don't go raising line pressures the Transgo kit should have done that for you if you installed the correct springs (until you figure out if something is wrong or not), a correct install of the Transgo kit will yield a faster firmer shift.

I havent messed with the trans internals of my 02 TB in years, its up at 150k now so Im not gonna touch it ha!

With a Vette 1-2 servo and the HD2 kit, I ended up reducing the 1-2 line pressure but still have to run more for the 2-3 and 3-4 shifts. I havent touched the tune in it for probably a good 3-4 years now, shifts firmly all the time so Im not going to worry about it.

[Chevy366]

Obviously I am not a pro, I know what you are saying but have never done it. I worked for a summer at a trans shop back in my youth so I am not totally out of touch with trans internal mods.
I just know the HD2 kit for my 4L80e is way different then the one you are referring to, I don't know why one kit would be so different than the other, the kit I have says "Series A" and came with instruction on how to turn the 4L80e into a manual shift trans, meaning gears will only change only if you do it with the shifter, no automatic. The large spring in the left corner of the trans that was replaced is for line pressure increase, I know because I had a problem with a part in the kit and needed a new one and called Transgo and asked some questions while the customer service rep was on the phone, and I asked specifically about it.
Like I said the kit came with more springs than the one you pictured. Still have not run across the instructions.

[Chevy366]

I havent messed with the trans internals of my 02 TB in years, its up at 150k now so Im not gonna touch it ha!

With a Vette 1-2 servo and the HD2 kit, I ended up reducing the 1-2 line pressure but still have to run more for the 2-3 and 3-4 shifts. I havent touched the tune in it for probably a good 3-4 years now, shifts firmly all the time so Im not going to worry about it.

Yeah, if it ain't broke don't try and fix it. LOL

Yep with a Transgo kit it is best to start off with stock settings seeing that that is what the kit targets for increasing, I had a modded tune with line pressure and shift time alterations when I put my kit in, had to go back to stock because I was getting improper feed back from the increased shift times and pressure, once I went back to stock all was well trans and tune have not been altered since.

[ferocity02]

After roughly a week with my desired shift times set to 0.3s, I checked the transmission adaptive values using the logging software and they are all 0.00psi for all shifts in all cells.

The PCM does not appear to be making adjustments to match the desired shift time. Is there something I'm missing? Another setting that might disable adaptive learning?

Perhaps a code is causing it not to learn.

[joecar]

Log these pids:
- ADAPTCELL <-- not valid on some PCM's
- ADAPTSHIFT <-- not valid on some PCM's
- SHIFTLAST
- SHIFTERR
- SHIFTDELAY
- TFMPRS
- TRQENG
- GEAR
- TCCMODE
- VSS
- TP

Look closely at the shift times (SHIFTLAST).


On every F-car I looked at, the TAP values were always all zeros (I'm as puzzled as you are).

[ferocity02]

Thanks Joe. I have logged SHIFTLAST as well as the 1-2, 2-3, and 3-4 shift times and they are kind of all over the place. I'm not sure how close the PCM can get to the desired shift time in a stock vehicle so I have no point of comparison.

I'll probably just leave my shift times to all zero anyways but I'm just messing around since this is my first auto with EFILive.

I'll try logging ADAPTCELL and ADAPTSHIFT. They appear to be valid for me.

[joecar]

If you have a shift kit installed (the shift improver type, e.g. like 4L60E-HD2), then you should probably zero the shift times, this prevents the PCM from "correcting" the shift kit's "recalibration".

[ferocity02]

I logged ADAPTCELL and ADAPTSHIFT this morning. ADAPTCELL would vary from 1-6 roughly, and ADAPTSHIFT was zero the entire time. Should it not be zero?

There are no trans codes, but I do have P0102 for MAFless, but it is not a fault enabler for the trans.