ram1500rsm
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- Trabuco Canyon, CA
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- 2014
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- Hemi 5.7
Trying to get the basics wondering if somebody around have HPT experience with the trans. I don't have the 8 speed trans in my truck but my wife 14 Durango SXT AWD is equipped with it. Wife came to me a few weeks ago and asked "Honey, can you change my Durango to shift to 1st gear before coming to a stop ?" Lol i said sure easy peasy, i just need to grab some time 
First observation is the damn thing has to come to a complete stop before 1st gear is engaged, otherwise the trans remains in 2d gear even when slowing down to about 2-3mph without doing the stop. My 09 Pontiac G8GT was the same and i changed the trans to do a 2-1 downshift at no throttle and about 3-5mph. couldn't be any more easier and should be something easy to fix...
I opened the trans tune today with HPT (i have already written my own tune but never bothered with the trans cause i never done anything with it) and holy macro where is my output shaft speed rpm vs load table ? hahahaha
I'll start with the basics and see how far i can go to do something as silly as to change my 2-1 downshift
"Getting to know your ZF TCM. Sticky please for updates.
Originally Posted by Steven@HPTuners 
The ZF8 is used in many applications and when we originally added it last year, we tried to make it a little more Dodge specific, but quickly realized this was not an easy effort, especially as we add more manufacturers.
The ZF8 is better thought of as its own controller by itself and not a "Dodge" controller, because that's what it really is.
4WD Low are used only during 4WD Low applications, but the Hellcat does not ever use these. The reason you still see the tables is the operating system used by the Hellcat is not unique to the Hellcat, other applications that do have 4WD Low (the trucks) also have the same operating system. Because we define things by operating system, you'll see them in all applications, including unused ones.
Normal, Perf, Sport, Max: these are shift strategies. Which one is used by which mode is actually quite a cluster and we don't have an easy way to show which is which, so its being added as a loggable parameter in Beta, under "Clutch Shift Type". For example, on a Hellcat, Normal trans mode in Drive, uses "Normal". But put it into Manual Mode with Normal Trans still selected, and now it uses Perf tables.
It's also considered a "use the highest below this". For example, if your current type is Sport, but the table set only has Normal and Perf, it uses Perf. The idea being that Normal -> Perf -> Sport -> Max have increasing levels of shift speed and feedback.
As to the "Normal, Normal Perf, Sport, Sport Perf, Track" shift schedules, I've started to relabel some of this to better correspond to whats happening. Basically depending on your actual selected trans mode, how aggressive you're currently driving, and your perceived hill grade, the shift tables are designed to get more or less aggressive.
To explain this, I'll use the ZF9 as an example as I believe we will move everything to be more like it to better indicate this.
Attachment 81473
First, we decide our Aggression level. To do this, we need to know our current Shift Situation (which is basically your trans shift mode. In the Hellcat, Normal, Sport, Track, Valet, etc all have their own "situation"). This is loggable.
The situation automatically puts you into a certain range of "Driver Type". 0 being the least aggressive driver, up to a max of 14 being the most aggressive driver.
As well, there's a constant "counter" running thats basically an indication of the current aggression of your actions. Some situations may have a range, for example, 20 to 200 for your aggression counter. As you move up the counter, you start moving into higher driver types.
Finally, your driver type is mapped into an "Aggression". For example, we have lower type = 0, upper type = 4, lower aggression = 0, upper aggression = 1, this means that driver type 0 is aggression 0, driver type 4 is aggression 1. In between driver types are blended between the various aggressions.
For Dodge, we simply named the aggression modes. Normal = 0, Normal Perf = 1, Sport = 2, Sport Perf = 3, Track = 4. However, the Shift Pattern Aggression Mapping for the Hellcat actually has the highest aggression being 3, Sport Perf. I.e. the high part of the table for driver types 9-14 actually blends from 4 to 3 aggression.
Now once you know your aggression, you'll notice there are 5 tables for that given aggression. These correspond to your accel factor / hill grade essentially. On the ZF9, its labelled by the Shift ID youd see if you logged Shift ID, on the ZF8 we still have it labeled "Normal 0, Normal 1, Normal 2, etc."
Attachment 81474
But, by using the "Accel Factor" tables, you can see what your final factor will be. Unfortunately this isnt straight forward to describe as the inputs are based on measured G-Forces, estimated road grade, etc. But the gist is Accel Factor 0 is typically when you're going downhill, Accel Factor 1 is normal, 2,3,4 are proceeding amounts of aggression (heavy Gs) or uphill orientation. You can log Accel Factor directly as well to help actually know what you're currently in!
These are the standard, aggression based maps. As well, the ZF8/9 have 75 MORE maps for various other conditions, though usually not all of them are used. I've placed these in a non-aggression section, and it corresponds to stuff like Cruise Control, Rock Crawl modes, and so on. Which ID is used by the logic depends on what you're doing (Cruise Control), shift situation, accel factor, etc. It all depends on what that type is used for.
Attachment 81475
For example, if you have cruise control active with accel factor 1, this particular setup will use Shift Pattern/ID 35 no matter what shift situation you're in.
BUT WAIT, THERE'S MORE.
Even once you know this final shift pattern ID, it can be remapped into another ID entirely by one final table. On the ZF8 we tried to show this with a bunch of comboboxes, but ZF9 and moving forward we'll just show the raw table.
Attachment 81476
For our example, Cruise Control, Accel Factor 1, we desired pattern 35. However, this final step maps Pattern 35 to Pattern 67. Pattern 35 is never even used!
I wish I could tell you this is easy or straightforward, but its not. It's a lot to swallow and understand. Transmissions are getting easily as complex as engine controllers, and the ZF especially so because its designed to be used in so many different applications by different OEMs. Because of this insane amount of configurability for the OEMs, the actual mapping itself is equally as configurable.
Hopefully if you read through this a few times and try to follow along with your calibration, you can start to understand it a little. If you have more questions, just ask, I'll try to answer them as I can!"
I'll start doing some logging today today what shift strategies are in place here.
the SXT doesn't have sport or performance mode, we only have an ECO mode switch, and i have to press it to disable ECO mode every single time. Should be easy right compared to the R/T or SRT8
First observation is the damn thing has to come to a complete stop before 1st gear is engaged, otherwise the trans remains in 2d gear even when slowing down to about 2-3mph without doing the stop. My 09 Pontiac G8GT was the same and i changed the trans to do a 2-1 downshift at no throttle and about 3-5mph. couldn't be any more easier and should be something easy to fix...
I opened the trans tune today with HPT (i have already written my own tune but never bothered with the trans cause i never done anything with it) and holy macro where is my output shaft speed rpm vs load table ? hahahaha
I'll start with the basics and see how far i can go to do something as silly as to change my 2-1 downshift
"Getting to know your ZF TCM. Sticky please for updates.
Originally Posted by Steven@HPTuners The ZF8 is used in many applications and when we originally added it last year, we tried to make it a little more Dodge specific, but quickly realized this was not an easy effort, especially as we add more manufacturers.
The ZF8 is better thought of as its own controller by itself and not a "Dodge" controller, because that's what it really is.
4WD Low are used only during 4WD Low applications, but the Hellcat does not ever use these. The reason you still see the tables is the operating system used by the Hellcat is not unique to the Hellcat, other applications that do have 4WD Low (the trucks) also have the same operating system. Because we define things by operating system, you'll see them in all applications, including unused ones.
Normal, Perf, Sport, Max: these are shift strategies. Which one is used by which mode is actually quite a cluster and we don't have an easy way to show which is which, so its being added as a loggable parameter in Beta, under "Clutch Shift Type". For example, on a Hellcat, Normal trans mode in Drive, uses "Normal". But put it into Manual Mode with Normal Trans still selected, and now it uses Perf tables.
It's also considered a "use the highest below this". For example, if your current type is Sport, but the table set only has Normal and Perf, it uses Perf. The idea being that Normal -> Perf -> Sport -> Max have increasing levels of shift speed and feedback.
As to the "Normal, Normal Perf, Sport, Sport Perf, Track" shift schedules, I've started to relabel some of this to better correspond to whats happening. Basically depending on your actual selected trans mode, how aggressive you're currently driving, and your perceived hill grade, the shift tables are designed to get more or less aggressive.
To explain this, I'll use the ZF9 as an example as I believe we will move everything to be more like it to better indicate this.
Attachment 81473
First, we decide our Aggression level. To do this, we need to know our current Shift Situation (which is basically your trans shift mode. In the Hellcat, Normal, Sport, Track, Valet, etc all have their own "situation"). This is loggable.
The situation automatically puts you into a certain range of "Driver Type". 0 being the least aggressive driver, up to a max of 14 being the most aggressive driver.
As well, there's a constant "counter" running thats basically an indication of the current aggression of your actions. Some situations may have a range, for example, 20 to 200 for your aggression counter. As you move up the counter, you start moving into higher driver types.
Finally, your driver type is mapped into an "Aggression". For example, we have lower type = 0, upper type = 4, lower aggression = 0, upper aggression = 1, this means that driver type 0 is aggression 0, driver type 4 is aggression 1. In between driver types are blended between the various aggressions.
For Dodge, we simply named the aggression modes. Normal = 0, Normal Perf = 1, Sport = 2, Sport Perf = 3, Track = 4. However, the Shift Pattern Aggression Mapping for the Hellcat actually has the highest aggression being 3, Sport Perf. I.e. the high part of the table for driver types 9-14 actually blends from 4 to 3 aggression.
Now once you know your aggression, you'll notice there are 5 tables for that given aggression. These correspond to your accel factor / hill grade essentially. On the ZF9, its labelled by the Shift ID youd see if you logged Shift ID, on the ZF8 we still have it labeled "Normal 0, Normal 1, Normal 2, etc."
Attachment 81474
But, by using the "Accel Factor" tables, you can see what your final factor will be. Unfortunately this isnt straight forward to describe as the inputs are based on measured G-Forces, estimated road grade, etc. But the gist is Accel Factor 0 is typically when you're going downhill, Accel Factor 1 is normal, 2,3,4 are proceeding amounts of aggression (heavy Gs) or uphill orientation. You can log Accel Factor directly as well to help actually know what you're currently in!
These are the standard, aggression based maps. As well, the ZF8/9 have 75 MORE maps for various other conditions, though usually not all of them are used. I've placed these in a non-aggression section, and it corresponds to stuff like Cruise Control, Rock Crawl modes, and so on. Which ID is used by the logic depends on what you're doing (Cruise Control), shift situation, accel factor, etc. It all depends on what that type is used for.
Attachment 81475
For example, if you have cruise control active with accel factor 1, this particular setup will use Shift Pattern/ID 35 no matter what shift situation you're in.
BUT WAIT, THERE'S MORE.
Even once you know this final shift pattern ID, it can be remapped into another ID entirely by one final table. On the ZF8 we tried to show this with a bunch of comboboxes, but ZF9 and moving forward we'll just show the raw table.
Attachment 81476
For our example, Cruise Control, Accel Factor 1, we desired pattern 35. However, this final step maps Pattern 35 to Pattern 67. Pattern 35 is never even used!
I wish I could tell you this is easy or straightforward, but its not. It's a lot to swallow and understand. Transmissions are getting easily as complex as engine controllers, and the ZF especially so because its designed to be used in so many different applications by different OEMs. Because of this insane amount of configurability for the OEMs, the actual mapping itself is equally as configurable.
Hopefully if you read through this a few times and try to follow along with your calibration, you can start to understand it a little. If you have more questions, just ask, I'll try to answer them as I can!"
I'll start doing some logging today today what shift strategies are in place here.
the SXT doesn't have sport or performance mode, we only have an ECO mode switch, and i have to press it to disable ECO mode every single time. Should be easy right compared to the R/T or SRT8
