TM explination needed

[Jozuah]

Does anyone have an indepth link on what torque managment does ?
the system seems amazing to me and i would like to read up on it, i have looked on google and wikipedia but the descriptions are sparse to say the least.
thanks in advance Josh

[rrmccabe]

Does anyone have an indepth link on what torque managment does ?
the system seems amazing to me and i would like to read up on it, i have looked on google and wikipedia but the descriptions are sparse to say the least.
thanks in advance Josh

Hey Josh (fellow Iowan) :)

Well first keep in mind there are three things on these trucks you dont want to get confused. The TM (torque management) you mentioned, TC (traction control) and Stabilitrack.

To answer your question, TM is a method to soften the blow on the drivetrain (mostly transmission) during shifts. It basically cuts horsepower by reducing timing several degrees when your transmission shifts into the next gear.

So under wide open throttle your truck might be running 18-22 degrees (average) timing depending on your fuel, conditions and "tune". Your truck shifts into the next gear and the timing is reduced to lets say 5-10 degrees dependent on the amount of TM you are running. I have seen some tunes go into negative timing numbers during shifts as well, but I dont think this is good.

Hope this helps.

Rich

[Jozuah]

ahhhh gotcha that makes sence why the throttle is so slow to respond in park or neutral while not moving. running WAY retarded makes perfect sense

[85vette]

It would appear this is GM's acknowledgement that the current transmission is not capable of holding up in such a heavy vehicle, especially if it's an SS!

[rrmccabe]

ahhhh gotcha that makes sence why the throttle is so slow to respond in park or neutral while not moving. running WAY retarded makes perfect sense

Well the TM does not work except for during shifts. Not sure what you are referring to in park or neutral?? I can tell you the mechanical fan makes it slow to respond when you rev it. The Electric fans makes it much more lively.

Here is a good chart showing TM on a "tuned" vehicle. The TM is reduced from stock so the dips are not as large. But if you follow the RPM line it will show you where the shift is. The dip in timing where it shifts into the next gear is TM.

http://www.ss-shootout.com/site_images/tm-t.jpg

[juventus1983]

is there TM present on the I6 from the factory?

[ylab]

is there TM present on the I6 from the factory?

Does your truck use gas? :) Yes, there's a load of TQM present on the I6 motor as it comes from the factory. All the tunes currently on the market eliminate most of the TQM and leave just enough to protect the tranny.

[MTPockets]

This is why you see more and more throttle by wire equipped engines now. It makes for much easier TQM execution. Flooring the go pedal doesnt mean WOT anymore.:cry: The PCM controls much of the throttle position, hydraulic pressure in the trans, ignition timing, fuel pressure...:eek:

Joel

[rrmccabe]

The SS does not pull throttle for TM.

[Air Defender]

The programming doesn't allow you to rev your engine above a certain RPM (3,300 rpm for me) while in Neutral or Park. This keeps you from over-revving the engine or dropping it into gear from neutral (neutral drop) on accident. Tried to do a neutral drop on an 06' TB rental in Dallas, not very exciting.

[Jozuah]

The programming doesn't allow you to rev your engine above a certain RPM (3,300 rpm for me) while in Neutral or Park. This keeps you from over-revving the engine or dropping it into gear from neutral (neutral drop) on accident. Tried to do a neutral drop on an 06' TB rental in Dallas, not very exciting.

thanks man.
Josh

[AlvinPCMforless]

There are 3 different ways the computer modulates torque via programming. Removing spark advance, ETC angle, and AFR. Most of the torque management people refer to is done during shifts and its mainly done via spark advance.

The PCM limits the amount of torque avaiable during shifts, hard starts from a stop, during different diagnostic errors, wheel slip, during brake torquing even with traction control off, etc.. The list goes on an on.

Contrary to popular believe. Torque management is not the magic key to tuning. Torque management usually makes full throttle starts from a stop feel a bit soft, shifts to feel a bit soft, but other than that you can hardly notice it by itself.

A tune picks up performance and throttle response mainly with different timing tables, fuel tables, shift points and timing, and shift pressure. Torque management is modified, but almost never entirely removed. (at least in our tuning)

It is very easy for a good tuner to leave a good deal of torque management left in the PCM without the customer being able to detect it by the way the vehicle feels.