torque management

[rlkimmel]

I don't remember which of the forums I was in where the topic was torque management but, as a dumb ass old grease monkey, I need to get my head wrapped around using an automatic transmission for actual torque control. (And, Yes, cars used to come with grease fittings - or at least a place you could screw one in.) Bearing in mind that in the '60s, no self respecting gear head would be caught dead in a performance vehicle with an automatic transmission, there would be no way to control torque by changing the shift points, trans oil pressure, or any other mod. Torque converters were and (I hope) still are strictly a mechanical function. To change a lock up RPM you had to change the converter. Decreasing trans pressure would just make the clutch disks slip and wear them out prematurely and would make for a sloppy shift. I always increased the pressure to give a quicker, stiffer shift. (slightly -- I drove the cars and trucks on the street most of the time.) Before programmers, I used B&M shift kits. Adjusting shift points was usually done at one of the local drag strips just to see if I could shave a few hundredths of the 1/4 mile times. the only thing I see on my truck that plays with the torque management is the Trac & Stab control. That garbage just plays with the throttle and brakes. I really would like a quick course on what would be incorrect in my thinking.

[Mike_Levy]

They don't use the transmission for torque control, they use the engine. They cut spark and close the throttle blade.

[rlkimmel]

They don't use the transmission for torque control, they use the engine. They cut spark and close the throttle blade.

Yes, that much I understand. That is all part of the trac and stab control. they also play with the each of the brakes separately. Sometimes it actually helps maintain control. BUT, sometimes, it can get you into some really DEEP shit. I don't like the idea of a computer deciding when the brakes and gas should be used and how much. When I had my Z28 (and I was a lot younger, braver, and a whole lot dumber) I got myself into a few situations where the only way I got around some tight turns without becoming part of the scenery was to break the back end loose and power slide through the turn. Didn't someone leave a post about controlling torque by retuning the TCM? Or is it just the alzhiemers (SP?) kicking in on this end.

[Mike_Levy]

I don't think the TCM has anything to do with how torque is sent out.

I did a power slide with the V yesterday with the TCS off and the car did a 180 (and I almost crapped myself), so sometimes its good to have.

[mikel]

there is trans torque management....

[Mike_Levy]

How does that work? The transmission can't change power or brake or anything. All it does is transmit the power. What does it purposely slip the clutches or short shift?

[mikel]

well, its called trans TM because the request comes from the trans, but it is still generally using the PCM to pull timing.

you can log trans tm on the V. With the stock tune it will go to -126° of spark on WOT upshifts

[rlkimmel]

I don't think the TCM has anything to do with how torque is sent out.

I did a power slide with the V yesterday with the TCS off and the car did a 180 (and I almost crapped myself), so sometimes its good to have.

You're very lucky that you only "almost." You can't just floor the gas peddle and start sawing on the steering wheel or the rescue squad will end up sawing on your car to get your body out of it. You have to learn to balance power and steering so the ass end hangs out a little bit further than the front and you end up steering in the opposite direction of the turn. I'm not questioning your driving ability but you have to learn to power slide to do it safely. I will suggest that you find some old pony car Trans Am driver like Parnelli Jones who left a bunch of rubber around the courses like Mid-Ohio and The Glen to teach you how to do it. I haven't watched a NASCAR road race for a while. Maybe that would be a good place to watch and ask a few questions at an autograph session.

[Mike_Levy]

Don't worry about me. I've been through 8 performance driving courses. I know how to do it, its just sometimes the road has less stick then you think it does and things get ugly. I've slid the car around this exact corner probably 40-50 times with no issues. Just once it rotated a bit too far and I had to nail the brakes.

[mikel]

thats the problem, brakes
stay on the throttle and drive through it

[Mike_Levy]

When you're looking at the curb, instinct says "Nail the brakes!!!".

[rlkimmel]

Don't worry about me. I've been through 8 performance driving courses. I know how to do it, its just sometimes the road has less stick then you think it does and things get ugly. I've slid the car around this exact corner probably 40-50 times with no issues. Just once it rotated a bit too far and I had to nail the brakes.

As I said, I'm not questioning your driving skills. I just don't want to read in here "Hey, remember that guy Mike Levy." As Mikel said in a following post, "Gas, not brakes." You have to "adjust" your thinking and train your right foot to do what instinct is screaming "DON'T." In most "OH, SHIT!!!" situations, hitting the brakes will guaranty you'll swap ends probably until you hit something and the end result will be "OOOHHHH, SHIIITTT!!!! <<CRASH!!>>. I spent a lot of time in a large empty parking lot, late at night, practicing before I even thought about trying it on the street. BTW, trying it with Trac and Stab on can be considered as being put in "TOO deep shit." You would be looking at a roll over.

[rlkimmel]

When you're looking at the curb, instinct says "Nail the brakes!!!".

My most memorable experience on forcing a power slide around a 40 mph turn at about 70 involved looking directly at a thirty foot stone high wall. If I would even have thought about tapping the brakes, I would have been a permanent part of that wall. (And, yes, the guy in the back seat DID shit himself, seriously.) I never said that radical maneuvers were smart or even sane but, lets just say that when you really pushed the edge, sometimes the only way to survive was to make a radical move and you never had time to do anything but react. Ok, back on topic.


Any word on the ECM tunes for my Colorado? I don't really care about the TCM mods yet but, since gas is back over $4/gal, I'm getting a lot more interested in better tunes. Still willing (and hoping) to Beta test and actually looking forward to it. I'll test any of your tuners for you but I want the Trinity for the gauges and other features. (GM took out the oil pressure gauge and replaced it with a nice idiot light.)