Torque management in action

[emarkay]

This snippet is about 700 frames, or approx. 7 seconds.

Starting from left, with about 2% to 100% throttle (floored!), you can see the transmission downshift into first, as RPM and VSS start to climb. Then as PCM calls for tranny to upshift into second, note the spark advance - it goes from the +25 range to -5 for a FRACTION of a second as the tranny shifts, as indicated by the RPM drop. Also note the (insignificant) 0.4 of KR.

Those who think TM is a major ET limiter or HP killer, can see why it's not that big of a factor, and why leaving it alone, if modifying your PCM program, is a good idea for the life of the car.

Now if you have substantially modified the drivetrain.....

[joecar]

Yes this makes a good case for leaving TM enabled so it can protect the driveline :!:

Even with a modifed driveline, the trans life still can be extended with TM enabled; most people who modify the driveline also modify the engine so the same reasoning applies over again;

:wink:

[bink]

This snippet is about 700 frames, or approx. 7 seconds.

Starting from left, with about 2% to 100% throttle (floored!), you can see the transmission downshift into first, as RPM and VSS start to climb. Then as PCM calls for tranny to upshift into second, note the spark advance - it goes from the +25 range to -5 for a FRACTION of a second as the tranny shifts, as indicated by the RPM drop. Also note the (insignificant) 0.4 of KR.

Those who think TM is a major ET limiter or HP killer, can see why it's not that big of a factor, and why leaving it alone, if modifying your PCM program, is a good idea for the life of the car.

Now if you have substantially modified the drivetrain.....

One pic = 1000 words! Thanks emarkay.
joel

[BowlingSS]

What about removing the TM when installing a torque converter? I have heard of a lot of people doing this after adding a TC.

BowlingSS

[emarkay]

TM protects the transmission AND MORE IMPORTANTLY the differential.....

[farmtruc]

TM is EVIL!

It regulates torque output to the wheels, who wants that :?:

[Drake]

Hoo boy... it'd be nice to get a definitive answer on this.

[farmtruc]

TM will affect other vehicles differently, in this case a camaro was used as an example, but you ask any late-model truck owner and he'll disagree.
TM will have little affect on a corvette, some on an f-body and greatly reduce power and slow you down in the 1/4 mile for the trucks.
TM will slow a truck down so much, once the mods start, it will literally keep you powerless for about a second when it's doing its job.
The electronic throttle body equipped vehicles really take a beating from TM.
Just my opinion, but if you have a stock trans, remove about 60%, a shift kit 100% or if you don't care 100%.
There are a lot of drivers out there with no TM and they haven't had any problems.

later,

[Brains]

On my 1998 Formula, 6-speed, it wasn't TOO bad unless I really banged out a fast powershift. It'd then literally take a few tenths of a second to get the timing back, and that's time better spent pushing the car down the street/track. On my 2004 GTO A4, TM is (was) a MONSTER. The performance gain between with and without is incredible. As far as protecting driveline components, the rear end is much less likely to break on a shift (especially in automatic trans vehicles) than it is on the launch. Bringing the transmission into the picture, the 4L60e's weak link is maintaining enough apply for the high gear (3/4) pack. I left TM in place for the 2-3 and 3-4 shift, but eliminated it entirely for the 1-2 shift. The band is not only plenty strong, but in the (unlikely) event it ever failed its damned near the easiest component in the transmission to replace

[Bruce Melton]

I wonder if they migrated this TM to the MN6 C6? I hear there is something going on with them that is kicking power back under stress???