Torque Management ????

[danman]

 

Hello Everyone,

 

I've noticed in a few of the other posts on this site to brief mention of torque management, with regards to the computer controlling the transmisson.

 

My question is how dose it work, dont need the fine details just an overview? And could this be the reason that no matter what I do I'm unable to do a burnout on my 2000 Tahoe Limited (old body style)

2wd.

 

Thanks for your input. some day there will be SilveradoSS parked in my driveway, just as soon as i can get the wife to change her mind on a new minivan.

 

[Extreme4x4]

Someone may need to correct me, because I am not sure about the GM's on this.

 

However, I believe that torque management is a condition where the torque is reduced (by whatever means) at shifts, to help the transmission survive in the long run.

 

In the Lightnings, for instance, 4 cylinders are dropped at shift. Supercharged engines put so much torque to the transmission....... so quickly........ that they can destroy a tranny in pretty short order (from the torque shock alone). You have to consider that the L runs the Powerstroke diesel auto trans also (well, last years model....... the 4-speed), for extra strength.

 

Many people who get chips in their Lightnings have this dropped....... the line pressure raised........ and the shift points raised. This has caused alot of premature failure of transmissions in modified L's (for instance, raising line pressure causes premature pump failure because it is now working outside of its design perameters). Some trucks with chips only have had failed transmissions due to this.

 

Personally...... the .1-.2 that you get in the quarter is not even close to being worth the risk. When we do the chip and the pulley (4lb), we will make sure that the chip is not programmed to do anything to the trans. We will upgrade the trans with a Factory Tech valve body (he builds the 4R100 trans for Ford...... so he knows more about them than about any person alive) to beef it up the correct way.

 

While eliminating torque management sounds like a good idea for an easy and painless couple of tenths........ think about what it could be doing to the trans in the long run. The factory didn't just put it in there to piss you off.

 

Something to think about.

[dcairns]

Found this bit from GM were they are talking about the 460e transmission

When a driver mistakenly subjects a vehicle to an abusive maneuver, such as moving quickly from drive to reverse while rocking the car to get out of a snow drift, abnormal wear can occur. The 4L60-E's PCM helps to protect the powertrain by retarding spark to reduce engine output during such situations. Similarly, the PCM briefly cuts engine torque prior to each shift to reduce driveline lash, thus producing smoother shifts

[Extreme4x4]

LOL, what a politically correct statement. Aren't manufacturers statements about why they do something funny. They don't want to say "we are reducing the torque at shift to allow the transmission to have a longer life." Ford says the same thing, btw.

 

Just as a point of information........ before electronically controlled transmissions came out (and this is still used today), in the valvebodies, there were little tiny plastic discs. These discs are buffers that slow down the flow of fluid to give the smoother shifts that some people like. When you do a shift kit, you usually remove these buffers.

 

Now they say they are reducing the torque to do this...... sure it is a side benefit......... but the real reason is tranny life. Something tells me that if I took the valvebody off of a 4L60E, or a Ford 4R70W...... that I would still find those little buffers in there.

[SSilverado60]

Yup, it pulls a lot of timing between shifts, this is the reason many people may complain about their trucks "falling flat on its face" when it shifts into second. TOrque management is dumb. It is ok if you are not planning on modifying your truck, but if you are like 99% of the people here that do, then it is just another thing to work around, and as far as it extending tranny life, its not going to help on a modded truck, you will most likely be pushing the limits of the trans anyways, so you might as well have some crisp shifts while you're doing it.

[Pilot135R]

Decisions! Decisions!