hi, can anyone helop me out and explain to me the different types of traction control availible on automobiles? i've heard about posi-traction and all that, but i hve idea what they are nor how they work. also lockers (for offroading)? eh?

 

Automobile, or off road truck? Most 'traction control' systems on luxury autos use computer controlled ABS systems or engine governors to limit wheel slip. But it is best at speed. Conversely things like limited slip diffs and lockers work best for slow speed off-roading. You usually only see such features on off road trucks or cars set up for drag racing.

'Posi-traction' is just the GM tradename for a limited slip differential. Ford calls it something else. I have no idea why the GM name stuck so hard..

 

Well the systems break down into active and passive assists.

Passive systems use lockers, limited slips and so on to distribute torque. Although lockers can be automatic or manual, they are not active devices in the way I'll explain in a bit. Similarly limited slips and their variants split the torque up in some way, but do not totally assure all wheels get equal torque.

One big thing to think about is all wheel drive vs. four wheel drive. In all wheel drive there is some kind of "differential" like device in the transfer case. For systems with full time all-wheel drive or full time 4 wheel drive (really all wheel drive), this device allows the front and rear wheels to turn at different speeds when required. It can be a simple differential, or a "viscous" coupler and may be always there, or turned on as needed.

Really, you only have a real transfer case for four wheel drive where you can shift the mode and ratio. It's just a center differential or coupler in all wheel drive vehicles without the option to change the mode.

Real all-wheel drive does not guarantee full available torque to all the wheels. Four wheel drive does IF you have lockers front and back.

In the traction control arena, most systems are active. In many cases, there are only standard differentials front and back. How they control torque distribution is a computer controlled variation of an old trick -- putting the brakes on to impede a spinning wheel and move torque to the gripping wheel. Such "active" systems can selectively apply the brakes to any wheel that is spinning. In addition, there may be a center differential that is controlled the same way to allow torque control betwen front and back wheels.

One additional, and occasionally troubling, aspect of traction control systems is engine power reduction. Many systems will actually fight back the throttle to prevent you from spinning the wheels. This can be a real problem offroad.

Really good all-wheel drive trucks also have a real four wheel drive mode that can be selected. They give you the best of all wheel drive for slick roads, and four wheel drive for extreme conditions. It really pays to look into how each vehicles traction control system works, and what modes it works in, before buying it -- especially if you go off road.

So, to summarize:

Best offroad: good transfer case with lockers front and rear, preferably selectable.

Okay offroad: good transfer case with auto lockers or LS. Lockers giving you the best off-road tradeoff, LS giving you the smoothest on-road driving.

Also okay: all wheel drive with a center differential lockup to obtain four wheel drive. May or may not be able to put lockers front and rear as well.

Bad: All wheel drive with active controls that do not have overrides. These systems, except in very pricey vehicles, are designed pretty much of regular driving.

I'm sure I've missed something, but someone else will chime in or link something. Sorry if it's a bit rambly -- I'm at work.

 

damn n3els....u tha man....u know everything about everything!!!!

 

Of course your good/bad list is nearly the exact opposite if your priority is on-road/high-speed handling on pavement w/ snow/ice/dirt patches. It all depends on what you're after..

 

Ah, true -- that represents my bias. Sadly, I didn't even THINK someone would be asking the question for on-road use, lol! Tells you where my head is at...

 

Yuh, and here I find myself heading progressivly in the OTHER direction.. Might as well give me a down-town condo and start calling me 'yuppie'!

 

Uh, yup...

Hey, as your income grows, you can have an offroad truck, and a downtown cruiser as two different vehicles. Why not?

 

Hmm, why not?! Prolly 'cause I'm getting to the age where other things are going to become excessively important, like owning a home, mabye <GULP> getting hitched and having a <SOBBING> family or something.. The other day I had the thought of selling off my bike, not to get another one, just to get the cash and throw it in savings. ..ach! I'm done-for! Put a bullet in me.. :(

 

lol! No, it's all good! Then, when you get to my age, and the kids are costing you less, you can plan to go "big" again, lol!

And, I'm plumb out of bullets, sorry...

 

yeah, i've been looking into a home and definately family and gettin hitched, but even if i had a HUGE amount of income it all seems so overwhelming with payments and mortage and all....i dunno.....

my theory is this....buy a nice, big house, buy a BMW and a SUV, go ahead and do all the home improvements i want, and sum it up into one big *** loan from the bank. i may be $3-400,000 in debt, but at least i'll have everything i want for the rest of my life and i dont have to worry about next year, or the next house i move into or anything.

 

Don't count on it! .. Must be because I am derived from a Murphy, but everytime I think I'm all squared away and have things 100% under control all hell breaks loose! I'm starting to learn that control is an illusion and I might as well just have fun when and where I can.. Like the man says, "Smoke'em if you've got'em!"

 

well i'm good at making a bad situation good, or finding the best in it, so i could handle everything well....

i'm almost 20 years old, and i've been stressed as hell for the past 2 years...i already have grey hairs, but i'm alive and relatively happy, and i guess thas all that matters

 

I was gonna post some info, but Griggs already beat me to it. :)

And I found three grey hairs last week. :( I'm 20.

 

My mother and GF both claim they see grey in my hair. I am 27. .... I think they're full of crap though..

 

I'm blond (can't you tell from how I talk? :p) and it "hides" in there pretty well. I've got plenty of it, but it's blended in. Dark haired people it shows much more. For some reason you can really see it in my beard more than my hair.

 

haha this post started as traction control, now i think its about hair control

twist on events...haha

 

Twist on the torsion bar, and a pretty hairy ride results... :p

 

ah tu chez (sp?), very nice comeback

 

Im 19, i have no traction, its why my name on aim is TractionBound, im bound to have it one day.

I have no grey hair's, im hispanic, it will stay black till im 90.

And i had idea's when i read this topic, but John talks to much, and so does bubba, so they covered it all..:D

Good stuff..

 

How true..

 

very...its good though, good reading.

 

lol! Well, Colin's got to go a fair piece to talk more than I do -- but he's CLOSE! :p

 

Yea, he is, he has actually increased his "presence" in the last few weeks more than ever.

I think he likes you John..

 

Bah! It's like John says, it comes and goes like the tides. Things are slow around here this time of the year. W/ the holidays and all there are no conferences or major projects going down. This means fewer and more relaxed deadlines, so it's easier to get destracted w/ sites like this.

Although I do think that John and I make pretty good dart-boards for each other. I've sworn off posting to sites like this so many times I've lost count. Something keeps driving me back, arguing w/ the likes of John is probably part of it..

The influx of photo related convos hasn't hurt my post count either..