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 Post subject: Trans mod by cutting Torque Request Sense wire
PostPosted: Wed Nov 16, 2011 10:48 am 
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I have mixed feeling about this mod which is popular with the dodge and jeep guys with the 4.7 and 545rfe trans.

Essentially you would cut wire number 10at the TCM which is the torque request sense wire that goes from the TCM to the PCM.

Essentially what this does is when the trans is about ready to shift it sends a signal (probably goes from OFF to ON state) and tells the PCM to cut the power down slightly and that is is going to shift.

While this helps reduce the torque going to the trans it also slows down the shifts which isn't good either.
It is meant so that the average driver doesn't feel the abrupt shifting between gears.

What I don't like is that in the 4.7 application, while it has a good amount of torque it doesn't have as much as a mod'ed CRD unless it has a supercharger or other major mods to it.

Now with that being said the same 545RFE trans is used in 5.7L hemi applications in the Ram pickup, Grand Cherokee etc and in a heavier vehicle with more power and I know of no failures.

Some of the dodge guys even put in a toggle switch so they could turn this "feature" on and off from inside the cab.

Thoughts?


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 Post subject: Re: Trans mod by cutting Torque Request Sense wire
PostPosted: Wed Nov 16, 2011 12:03 pm 
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A member going by the name of GMCTD tried this years, literally, ago and reconnected it as I recall.
What your not thinking about is our CRD's product full torque under 2k rpms as opposed to a gasser that is just getting going at 2k :ROTFL:
Additionally our CRD's only having 4 cylinders produces that torque in two very big pulses per revolution :jester:

Try a search using GMCTD as auther and torque managment as a topic.

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 Post subject: Re: Trans mod by cutting Torque Request Sense wire
PostPosted: Wed Nov 16, 2011 12:05 pm 
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Joe Romas wrote:
A member going by the name of GMCTD tried this years, literally, ago and reconnected it as I recall.
What your not thinking about is our CRD's product full torque under 2k rpms as opposed to a gasser that is just getting going at 2k :ROTFL:
Additionally our CRD's only having 4 cylinders produces that torque in two very big pulses per revolution :jester:

Try a search using GMCTD as auther and torque managment as a topic.


Thanks Joe!

I must've missed it i'll try searching again under his UN


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 Post subject: Re: Trans mod by cutting Torque Request Sense wire
PostPosted: Wed Nov 16, 2011 4:07 pm 
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I'd be interested in GDE's take on that mod. As I understand it the torque converter in the CRD (the stock ones) is not up to full torque shifts and would bounce. Anyone know? Isn't that why were upgrading to the new torque converters?


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 Post subject: Re: Trans mod by cutting Torque Request Sense wire
PostPosted: Wed Nov 16, 2011 6:18 pm 
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The direct communication link from the TCM to ECM is not active on 2005. Not sure about the 2006 as the ESP might be controlling something through that wire. There is no torque management in either model year for gear shifting. It would have been helpful in reducing some early TC failures.

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 Post subject: Re: Trans mod by cutting Torque Request Sense wire
PostPosted: Thu Nov 17, 2011 10:18 am 
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GreenDieselEngineering wrote:
The direct communication link from the TCM to ECM is not active on 2005. Not sure about the 2006 as the ESP might be controlling something through that wire. There is no torque management in either model year for gear shifting. It would have been helpful in reducing some early TC failures.

Excellent info!

Thanks


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 Post subject: Re: Trans mod by cutting Torque Request Sense wire
PostPosted: Thu Nov 17, 2011 12:19 pm 
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Years ago I tried it for a few days.
I didn't notice any difference in performance so I put it back the way it was.

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 Post subject: Re: Trans mod by cutting Torque Request Sense wire
PostPosted: Thu Nov 17, 2011 8:08 pm 
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Here's what Mr Mopar says in this thread.
viewtopic.php?f=5&t=30530&p=312317&hilit=torque+reduction#p312317

The torque reduction during shift has always been there. Can't say more about it or F37 for obvious reasons.

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 Post subject: Re: Trans mod by cutting Torque Request Sense wire
PostPosted: Thu Nov 17, 2011 8:57 pm 
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Joe Romas wrote:
Here's what Mr Mopar says in this thread.
viewtopic.php?f=5&t=30530&p=312317&hilit=torque+reduction#p312317

The torque reduction during shift has always been there. Can't say more about it or F37 for obvious reasons.

Kinda makes you wonder if it isn't there for a reason...


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