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Thread: 727 swap on a Gen III 6.4

  1. #1
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    727 swap on a Gen III 6.4

    I have a 21 Challenger 1320. I have a couple of questions but I think i know the answer to the first one. Are any or all of these things possible through HP tuners?

    1) is there a way to use a tuner to change the input for using the transbrake? im guess NO. but for example you have to run through so many steps to activate it on the line that its virtually impossible to activate it every time, unless the other drive is slow. I would want for it to be like 2 steps of pulling both paddle shifters and run your throttle, let go to launch. Instead of pull both, push brake, throttle, let go of one, let off brake, let go of other paddle to launch.

    2) Again I doubt this is possible unless there is a box to fake all of those inputs to the transmission and force it to run the Tbrake on a single button.

    3) if I cant do that, is there a way to shut off the TCM so I can run a 727 transmission? or one equivalent for my purposes, since playing with the Tbrake is easy enough to set up on old school transmissions.

    4) I suppose that would also mean I need it to run in "drag" mode 100% of the time as well?

  2. #2
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    Hello,

    1. There is no way to change TBrake via HP Tuners.
    2. It is done the way it is due to safety reasons. TBrake is not a "natural" thing for a transmission, so, it has to meet safety criteria to become active
    3. It would be a hustle... CAN communication, all electronics communication & controllers... you would need a VERY good gateway to emulate everything
    4. Drag Mode pushes the TM "to the limit" in a more frequent way... yes, you can run Drag all the time, but there will be some downsides in doing it.

    I guess the solution to you is:
    1. get quicker on activating TBrake
    2. or, have it in the old fashion way (do the "TBrake" yourself with brake and throttle)

    DodgeBoy
    YouTube: https://www.youtube.com/@dodgeboy2785

  3. #3
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    you ever been to the track dodge boy? ever installed a valve body that incorporated a brake?

    ZF HP70 or HP75 will NEVER get a trans brake. Never...

    i know i know... sipple says they are working on one but its never gonna happen

    even if you could figure out a way to get one of these things in 1 and R at the same time... the ratios for those gears are NOT the same

    reverse is a taller gear

    the car will move as torque is applied


    *the gimmick dodge is calling a brake can be had with a tazer op

    push 2 buttons, let go of one of them, and have at it
    Last edited by LilSick; 07-04-2023 at 05:22 PM.

  4. #4
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    Quote Originally Posted by LilSick View Post
    you ever been to the track dodge boy? ever installed a valve body that incorporated a brake?

    ZF HP70 or HP75 will NEVER get a trans brake. Never...


    *the gimmick dodge is calling a brake can be had with a tazer op

    push 2 buttons, let go of one of them, and have at it
    right i know its not a true trans brake. thats why i said i already figured its a no go.

    so then if i did want to swap out for a different transmission, is there a way to either run it using HP and the stock computer or have it not control A transmission? as i think a 727 is mechanical and not electronically operated. if i am not able to just shut off the TCM or what ever, will i lose my gauges and 8.4 uconnect operations if i run a different system (ie megasquirt...). maybe the standard pcm is a piggy back just to show my dash stuff?

    sorry i know this kinda gets off the HP tuners use but i dont realy know much about how to manage the PCM, TCM, ECU for this car. and i havent found any one who is trying anything different with this car.

  5. #5
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    Quote Originally Posted by LilSick View Post
    you ever been to the track dodge boy? ever installed a valve body that incorporated a brake?

    ZF HP70 or HP75 will NEVER get a trans brake. Never...

    i know i know... sipple says they are working on one but its never gonna happen

    even if you could figure out a way to get one of these things in 1 and R at the same time... the ratios for those gears are NOT the same

    reverse is a taller gear

    the car will move as torque is applied


    *the gimmick dodge is calling a brake can be had with a tazer op

    push 2 buttons, let go of one of them, and have at it
    Sounds like this became a personal forum and not a Transmission Tune Forum.

    What I have done (or not) is none of your business. But, I can guarantee I have much more experience than you on transmission tune. So, stay in your lane and respect the others.

  6. #6
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    Quote Originally Posted by spoolboy View Post
    The Tazer thing is not the same. The Demon/1320 transbrake applies the clutches for 1st and 2nd, not 1st and reverse as in most conventional transmissions (TH, 727, etc).

    Attachment 134128
    what is LPS solenoid?

    and there is a normally closed park solenoid?

    where did you get that chart?

  7. #7
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    Quote Originally Posted by DodgeBoy_8HP View Post
    stay in your lane
    ditto

  8. #8
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    Quote Originally Posted by spoolboy View Post
    IF you are going for a full drag car, just run aftermarket management.

    It's fairly common to hang a TH400 on the back of a Gen 3 Hemi. You'd just need a manual trans calibration.
    thanks for the info, ill search for how to manual trans calibrate, and read up on mating a TH400 to it.

  9. #9
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    Quote Originally Posted by spoolboy View Post
    Line Pressure Solenoid.


    Attachment 134188
    sounds more like a regulator than a valve

    you think that is what HPT labels the 'pressure control solenoid'

    ???


    i was thinking if there is a solenoid for park maybe it could be used to build a brake?

  10. #10
    Quote Originally Posted by LilSick View Post
    you ever been to the track dodge boy? ever installed a valve body that incorporated a brake?

    ZF HP70 or HP75 will NEVER get a trans brake. Never...

    i know i know... sipple says they are working on one but its never gonna happen

    even if you could figure out a way to get one of these things in 1 and R at the same time... the ratios for those gears are NOT the same

    reverse is a taller gear

    the car will move as torque is applied


    *the gimmick dodge is calling a brake can be had with a tazer op

    push 2 buttons, let go of one of them, and have at it
    Dodge uses 1st and 2nd gear so if 1 fails, the car will not shoot backwards. Tazer does Line Lock not Trans Brake.

  11. #11
    To the OP, Someone makes an adapter to mount an A727 to the modern Hemi. It's a flex plate with 3 bolt patters. The only difference is the Hemi block does not have a top mounting hole. You will definitely want to tune the engine to not use MDS anymore and "probably" at least select "Manual" under Transmission settings. I am not a tuner, nor do I pretend to be.

    https://www.classicindustries.com/product/mn410799.html
    Last edited by dodgeboy; 09-20-2023 at 06:00 AM.