2020 Challenger Trans Torque management question

Hello?. I have a 2020 Dodge Challenger 6.4L with ZF8HP70. I have purchased TheTuning School book on Dodge transmission tuning using HP Tuners.

Going through the processes I ran across where the school asks to adjust (using Navigator 46854) Transmission> Torque Management > General. Under Max Torque Limit there is a cell called Max in which I have it set at 527 lb-ft

The tuning school asks to enter 100 lb-fts greater than what is generated or just enter 650 ft-flbs if I don?t know. I don?t know exactly because the car has never been on a dyno.



Now the problem is if I enter a value higher than 527 lb-fts I get code pop up (engine light). Looking at the code it states something like ?Trans torque request has been denied? Now then I go back drop the max torque down to 527 or lower I don?t get a code.

When I enter 650 I get the code and when I enter 527 I don?t get code.

I have Trans> General> Gear Base> Max (46856) and Torque limit max (46854) the same but I will not get a code with Gear Base set higher.

Questions I have is why am I getting this code?

I have a cam, long tube headers, CNC ported heads, and use nitrous between 75-100 shot. Do you think I?m making more than 527 torque especially when on the bottle?

Is this going to inhibit me getting full potential?

Just trying to find out what is going on.

Leave that one at 527

Right below is the table you may or may not eventually need to change

Self controlled max

Do you have a log from last time you made a pass at the track?

Quote:

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Originally Posted by LilSick

Leave that one at 527

Right below is the table you may or may not eventually need to change

Self controlled max

Do you have a log from last time you made a pass at the track?

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Thanks.... My computer that I can't use to tune has "Self Control MIN and MAX" my tuning computer doesn't. I have tuning computer in advance not basic layout... hmm.. don't know what's up with that.

No... I have never been at the track. Got a few logs around here on the road.

Depending on the transmission family (8HP30, 8HP45, 8HP55, ... , 8HP95), it will have a torque limit.

Unfortunately, it is not available on HP Tuners to change it. In case torque is set outside of the max value (from factory), it will set the code you mentioned.

Solutions:
- External TCM/TCU
- Work around on ECM broadcasted torque
- In case engine is delivering much more torque, upgrade transmission to next step in line

DodgeBoy.
YouTube: https://www.youtube.com/@dodgeboy2785
Email: [email protected]

For some reason its just he 650 hta is the issue. My car would get stuck in 3rd if i entered the 650 but try any other number below 650 and its fine.

Quote:

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Originally Posted by DodgeBoy_8HP

Depending on the transmission family (8HP30, 8HP45, 8HP55, ... , 8HP95), it will have a torque limit.

Unfortunately, it is not available on HP Tuners to change it. In case torque is set outside of the max value (from factory), it will set the code you mentioned.

Solutions:
- External TCM/TCU
- Work around on ECM broadcasted torque
- In case engine is delivering much more torque, upgrade transmission to next step in line

DodgeBoy.
YouTube: https://www.youtube.com/@dodgeboy2785
Email: [email protected]

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I worked with it some more. I was able to get 575 without it throwing a code. 580 would throw a code.

I did a log yesterday with a WOT pull and the actual torque only went up to 515 ftlbs so I'm good. I appreciate your help.

Quote:

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Originally Posted by MakurFab

For some reason its just he 650 hta is the issue. My car would get stuck in 3rd if i entered the 650 but try any other number below 650 and its fine.

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I found that 575 is the highest I can go without the TCM throwing a code.

It's just a max torque limit. Plus there are a couple other tables that limit this number under the same tab and under the pedal characteristics tab.
My current tune is at 627 not that it really matters for me becuase I am no where close to that max limit.

Quote:

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Originally Posted by MakurFab

It's just a max torque limit. Plus there are a couple other tables that limit this number under the same tab and under the pedal characteristics tab.
My current tune is at 627 not that it really matters for me becuase I am no where close to that max limit.

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I was in shock when I first uploaded the tune that I had created using The Tuning School book. I had it set on 650.... but I didn't know what was causing the code. So I uploaded my old tune and the code went away. After that it took some comparing files on what I changed and found what the problem was..LOL ... thanks.

Yeah, I bought the same book. It's a good place to start but leaves alot of questions and doesn't even touch on downshift and TCC settings. Trail and error and use stock tunes as reference is some advise. Understanding these transmission is pretty important and an advantage over most becuase most shops don't know how to tune them to take full advantage when pair with a good engine build or even a stock engine.

Quote:

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Originally Posted by MakurFab

Yeah, I bought the same book. It's a good place to start but leaves alot of questions and doesn't even touch on downshift and TCC settings. Trail and error and use stock tunes as reference is some advise. Understanding these transmission is pretty important and an advantage over most becuase most shops don't know how to tune them to take full advantage when pair with a good engine build or even a stock engine.

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Yes sir you're correct. They missed elaborating on a lot... LOL TCC settings blows my mind. I just leave them alone. I had the trans tuned by a fellow and use his tune file to compare to stock , what he changed, and what I change just to learn how these work. He made some changes in TCC settings but I don't ever touch them.... because.... I don't understand it... lol

tcc tuning has not yielded anything drastic at the track

i leave off idle and flash to 3450 rpm

have tried a bunch of ideas that i really thought would help but the time slip does not lie

tcc tuning has yielded a DRAMATIC CHANGE on the street

Quote:

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Originally Posted by LilSick

tcc tuning has not yielded anything drastic at the track

i leave off idle and flash to 3450 rpm

have tried a bunch of ideas that i really thought would help but the time slip does not lie

tcc tuning has yielded a DRAMATIC CHANGE on the street

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The tuning school mentions of turning the TCC off altogether except in gears 6 thru 8 gears. I tried it and didn't like it. DFCO wouldn't come on for some reason. Seems to me the car launched better with the TCC on. Must be the way it was tuned.

Quote:

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Originally Posted by Mully95

The tuning school mentions of turning the TCC off altogether except in gears 6 thru 8 gears. I tried it and didn't like it. DFCO wouldn't come on for some reason. Seems to me the car launched better with the TCC on. Must be the way it was tuned.

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If you do what tuning school is saying, you will bake your TCC very quicly...

leaving the converter unlocked will not hurt the converter

it will put additional heat in the trans fluid tho

i drove my car unlocked (gears 1 - 4) for over a year while i was building a lockup map that worked better than unlocked

unlocked at the track the car is slightly more consistent but slightly slower

Quote:

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Originally Posted by MakurFab

Yeah, I bought the same book. It's a good place to start but leaves alot of questions and doesn't even touch on downshift and TCC settings. Trail and error and use stock tunes as reference is some advise. Understanding these transmission is pretty important and an advantage over most becuase most shops don't know how to tune them to take full advantage when pair with a good engine build or even a stock engine.

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I felt that tuning school book wasn’t even worth the paper it’s printed on. Just a lazy man repeat of the exact same thing over and over from one transmission to the next, just their personal settings without actually explaining anything at all.

One thing is some TCC slip, another thing is TCC completely open.

Yes, closing TCC on high torque and high rpm it does a lot of harm to hardware.

Anyways, do what is best to you. I just dont recommend and dont do it.

Quote:

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Originally Posted by DodgeBoy_8HP

If you do what tuning school is saying, you will bake your TCC very quicly...

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You might not remember but you did a complete transmission tune for me. I like to learn how things work and bought the Tuning School book just to know what does what. I always go back to your tune however.... LOL

I bought the engine book as well.

Quote:

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Originally Posted by Mully95

You might not remember but you did a complete transmission tune for me. I like to learn how things work and bought the Tuning School book just to know what does what. I always go back to your tune however.... LOL

I bought the engine book as well.

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Glad to hear it!
I am sure you have a great baseline

cheers!

Quote:

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Originally Posted by Mully95

I worked with it some more. I was able to get 575 without it throwing a code. 580 would throw a code.

I did a log yesterday with a WOT pull and the actual torque only went up to 515 ftlbs so I'm good. I appreciate your help.

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I have had performance pages show as high as 530hp which is not accurate obviously but it was one of my better running tunes.