ATRAC question

[DrSolar]

The Stig previously said:

Atrac is great.
I've been wondering if Atrac is better in some situations(icy, slippy) than even being fully locked?

In some cases yes. Lockers can hamper your ability to steer the vehicle in tight places and it adds a lot of stress to the drive line. ATRAC does not, but with a locker you are not steeling power from one wheel, all wheels have power all the time with a locker thus a fully locked rig is a real 4x4 with all 4 tires spinning.

I use my ATRAC only 90% of the time and the locker only comes on for short spurts and then I turn it off to avoid possibly breakage. Problem is with the IFS front end, the locker is often needed when tires lift off the ground.

As for Ice and lockers, lockers will do crap on ice, maybe make it worse. ATRAC might do you some good...maybe. Best thing for ice are tire chains or tire spikes, 4WD on ice is just having four tires spinning rather than two.

[ballkillerxxx]

i have it just havent had the chance to use it yet

[The Stig]

DrSolar previously said:

In some cases yes. Lockers can hamper your ability to steer the vehicle in tight places and it adds a lot of stress to the drive line. ATRAC does not, but with a locker you are not steeling power from one wheel, all wheels have power all the time with a locker thus a fully locked rig is a real 4x4 with all 4 tires spinning.

I use my ATRAC only 90% of the time and the locker only comes on for short spurts and then I turn it off to avoid possibly breakage. Problem is with the IFS front end, the locker is often needed when tires lift off the ground.

As for Ice and lockers, lockers will do crap on ice, maybe make it worse. ATRAC might do you some good...maybe. Best thing for ice are tire chains or tire spikes, 4WD on ice is just having four tires spinning rather than two.

Ya thats the other advantage to atrac less broken diffs.
So is it the loss of power that means a front locker is better than atrac in hard spots? So on real smooth slippy rocks would atrac be better than lockers, like it is on ice?

[nlk125]

The Stig previously said:

Ya thats the other advantage to atrac less broken diffs.
So is it the loss of power that means a front locker is better than atrac in hard spots? So on real smooth slippy rocks would atrac be better than lockers, like it is on ice?

Basically think of ATRAC as traction control for LOW RANGE. Some situations need wheel spin, and in others you want NO SPIN. If you're in a situation where traction is marginal, and wheel spin is not desired, turn on ATRAC (or, just leave it on all the time, and turn it off when you DON'T need it). However in sand, mud or similar, you sometimes need wheelspin for floatation/tread clearing, whatever. So if you couldn't turn the traction control off to allow the wheels to spin you'd be pooched. HENCE Switchable ATRAC. The only difference between Traction control (trac) and ATRAC as I understand it, is that Traction control will apply brake to the slipping wheel, AND reduce engine power. Atrac will NOT reduce engine power. There are MANY MANY thread covering ATRAC... Try searching for more thorough discussions on the topic.

Cheers!

[The Stig]

Ya I know traction control pretty well. I was just wondering how good it is on the rocks, or why a front locker is better(what specific sort of situation is a locker better).
Of course it's just like any traction control except that it doesn't reduce throttle... I didn't know about that...

[DrSolar]

The Stig previously said:

Ya I know traction control pretty well. I was just wondering how good it is on the rocks, or why a front locker is better(what specific sort of situation is a locker better).
Of course it's just like any traction control except that it doesn't reduce throttle... I didn't know about that...

The easy answer...Yes and No
Do you want both tires spinning with a 50/50 split of power in the front or do you want one tire spinning faster than the other, thus getting more traction on one side as opposed to equal on both. If one front tire is in the air ATRAC should do fine by trying to lock up the tire in the air so the tire on the ground gets traction. If both tires are on the ground and traction is poor, the locker would do better.

A locker makes the vehicle a true 4x4. Without a locker only ONE tire spins on the back and ONE on the front (i.e. gets full power). As the powered wheel slips the power is transfered by the diff to the other tire. With a locked diff both tires spin with full power at all times which equals lots of traction. This can be good and bad at the same time.

ATRAC has to slow one tire to power the other, it fools the diff into thinking that one tire is slipping more than it really is. ATRAC is an old trick used by setting the hand brake with a Posi in the rear that would make it like a mini-locker (a very poor one), same concept new package. I used to do this in my XJ and drove over everything basically with open diffs.

With ATRAC on and the rear locked you should have no issues crawling over anything with exception to very extreme stuff. Rely on your skill over the hardware and you will be better off. The real question is how do you navigate over something that is slippery without the aid of a traction device when you need one.

Did that answer it or am I way off?

[DEWFPO]

The Stig previously said:

Atrac is great.
I've been wondering if Atrac is better in some situations(icy, slippy) than even being fully locked?

If you are on any kind of sideways slope (camber), the ATRAC will be better on icy, slippery surfaces than a locker. If both wheels per axle spin and you have very little to no traction, then gravity is going to take you down slope (not necessarily the direction you want to go). The benefit in these conditions of having one wheel per axle not spin, is that it will try to keep you from sliding sideways. You may not move forward(or backward), but you rig should stay on track in most cases.

DEWFPO

[Biatch76]

I am locked front and rear and of course have the ATRAC. I have used both extensively and of course...it really depends on the situation on which is better. If you are trying to turn mid obstacle, ATRAC is very useful but I'd never trade having the option of being fully locked front and rear .

[FJSteveH]

Thanks everyone for all of the info. I took the advice and bought an FJ today (pick-up on Saturday): 4WD, auto, rear lock diff. Per everyone's input, I did not buy the $2600 upgrade package just to get ATRAC. I'll wait until I move to Colorado in October to get the ATRAC switch because I probably will not run into many icy roads here in Florida between then and now!

[frankv64]

Congrats on your new toy