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moose44 said:
The Titan's Active Brake Limited Slip (ABLS) Differential is a better version of regular LSD as far as I understand it, so what exactly is the "oversight on Nissan's part"? Nissan improves on the LSD AND offers true locking rear differential. What could be better than that? Or am I missing something here? Moose
Better is a subjective word. It would be crazy to think we all want the same thing, thus we have to see other people's points of view. I think LOTS of people are going to be VERY happy with the systems Nissan has in place. You sound like you are, and I'm happy for you, maybe even a bit envious. I however am just not yet fitting into that category. I love the Titan, and really want an '05, but this is an important issue to me.

- Active brake, what's wrong with it FOR ME? I do not want the computer applying the brakes to limit slip when I would rather drive the truck myself, I would rather feel the slip and then compensate for it myself. I do not want a truck that is happily applying the brakes while I am happily standing on the gas; the two just do not go together in my world.

- E-locker, all this technology is great, IF you want to drive in 4WD LOW. If you are in 4WD HIGH this technology is not at play. The greatest technology does not do a darn thing for ya if it is turned off.

- Oversight from MY point of view. I would rather have a traditional LSD. I could feel what the truck was doing and could compensate. If I wanted to spin BOTH back tires to help me get through the snow or mud I could. I would have the additional benefit of driving both back tires in 4WD HIGH, a gear selection I use way more often than 4WD LOW.

See my avatar? I play on racetracks, I have worked very hard to develop my car control skills, I am very much NOT into having the on board computer think for me.
 

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Quad T said:
- Active brake, what's wrong with it FOR ME? I do not want the computer applying the brakes to limit slip when I would rather drive the truck myself, I would rather feel the slip and then compensate for it myself.
For Me:

A LSD is always working, before any slip occurs.

The Active brake "applies braking force to a wheel that's losing traction."

Over 20 mph in 2hi or 4hi, if you lose traction you have lost control. Depending on the conditions, hope VDC can pull you through or you can recover.

I really would like to know how Active Brake Limited Slip differs from standard traction control. Does it work sooner, faster, apply more force? I don't see how ABLS is better than or equal to a regular LSD.

An open differential with traction control, is still an open differential.
 

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Bluto said:
For Me:
A LSD is always working, before any slip occurs.

Over 20 mph in 2hi or 4hi, if you lose traction you have lost control. Depending on the conditions, hope VDC can pull you through or you can recover.
I'm coming from the point of view that I want to be an active participant in my own slip. Just because there is slip over 20 mph not all the control is lost. I have been is mud conditions where I was powering through, both back tires were throwing mud, i.e. spinning and slipping, and I was not out of control. Consider Rally drivers, they "loose traction" almost the entire time they are driving, and clearly they have not lost control.
 

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Does anyone know why a mechanical LSD will not work with the ABLS? The way I understand it the ABLS brakes the spinning wheel. If the LSD stops the wheel from spinning then it should not brake the wheel. If both wheels spin it could brake both wheels. If traction is that low won't it do that anyway?
 

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I would have to agree with Quad on this. I don't really want my vehicle to have the final say in when the tires can and can't spin. I can't really judge the performance of ABLS in the sand and mud, since I have never experienced. I do know that tires made for this type of terrain are designed to use wheel spin to paddle out. Maybe the ABLS can compensate, maybe not. Bottom line is I want to be in control of the vehicle.
 

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Just so I understand the elocker--Does it only appear on vehicles that were made post april first??, and is it really that attractive of an addition?

thx
 

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Quad T said:
I'm coming from the point of view that I want to be an active participant in my own slip. Just because there is slip over 20 mph not all the control is lost. I have been is mud conditions where I was powering through, both back tires were throwing mud, i.e. spinning and slipping, and I was not out of control. Consider Rally drivers, they "loose traction" almost the entire time they are driving, and clearly they have not lost control.
I don't disagree, offroad is a different ball game. For day to day driving in sun, rain, and snow I'll take a LSD over traction control. I don't know if ABLS is any different than traction control. Will it cut the throttle if both wheels are spinning?

I have traction and stability in my current vehicle. It works good, I like it, it is not perfect. You can't power through anything unless you turn it off. It is a trade-off: safety vs. total control I can turn it off when I want to.

Can ABLS reduces engine output? Does the owners manual offer any more information?
 

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JS02 said:
Does anyone know why a mechanical LSD will not work with the ABLS? The way I understand it the ABLS brakes the spinning wheel. If the LSD stops the wheel from spinning then it should not brake the wheel. If both wheels spin it could brake both wheels. If traction is that low won't it do that anyway?
two different approaches to the same problem

ABLS applies the brake to the spinning wheel

LSD, when one wheel slips/spins the diff transfers torque to the wheel/tire
with traction & reduces the spinning on the slipping wheel

my question with ABLS is , when the brake is applied to the spinning wheel what happens at the diff with the torque ??

it's still an open diff so does the torque automaticly go to the wheel/tire with traction or is the caliper/disc just fighting against the torque on that side of the axle ??

also is power reduced (ignition retarded,fuel reduced) like on a electronic traction control system that uses the ABS that's so common on todays FWD cars ???
 

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here's a description of LandRover's system, same basic concept

www.worldoffroad.com/begin/begdiff.asp

Traction Control Systems

These are basically computer controlled systems and are largely found on sports cars and luxury saloons however a system has been available on Range Rovers since 1994. The Range Rover system works through the vehicles ABS braking system and utilises standard diffs. Using the principle that the diff is a lazy device, as discussed in What is Four Wheel Drive? , and only wants to send power the easiest way possible Range Rover traction control applies the brakes to the spinning wheel until it requires more power to turn that wheel than the one on the other side of the diff. This system only works on an ABS equipped car as these have the ability to sense the speed of each wheel in turn and apply the brakes as needed. The system generally works well but cannot be fitted retrospectively.
 

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cnatra said:
two different approaches to the same problem

ABLS applies the brake to the spinning wheel

LSD, when one wheel slips/spins the diff transfers torque to the wheel/tire
with traction & reduces the spinning on the slipping wheel

my question with ABLS is , when the brake is applied to the spinning wheel what happens at the diff with the torque ??


An open diff will transfer power to the wheel with the least resistance - therefore the power will go to the wheel that doesn't have the brakes applied.

also is power reduced (ignition retarded,fuel reduced) like on a electronic traction control system that uses the ABS that's so common on todays FWD cars ???
An open diff will transfer power to the wheel with the least resistance - therefore the power will go to the wheel that doesn't have the brakes applied.

Your 2nd question's answer is, i think, power is not reduced by the ABSL but by the VDC. You can turn that feature off.
 

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Bluto said:
For Me:

1. A LSD is always working, before any slip occurs.

2. The Active brake "applies braking force to a wheel that's losing traction."

3. I really would like to know how Active Brake Limited Slip differs from standard traction control. Does it work sooner, faster, apply more force? I don't see how ABLS is better than or equal to a regular LSD.

4. An open differential with traction control, is still an open differential.
1. Incorrect - the slip must occur before the LSD will start transfering torque to the other wheel

2. Correct - this causes torque to be transfered by the open diff. just like #1

3. I think "standard" traction control uses engine output to stop slipping - a useless feature if you ask me. In fact I wouldn't want it!

4. True for traction control - misleading for ABLS. The ABLS uses features of the open difff to make it act exactly like a LSD.

:cheers:
 

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keane said:
An open diff will transfer power to the wheel with the least resistance - therefore the power will go to the wheel that doesn't have the brakes applied.

Your 2nd question's answer is, i think, power is not reduced by the ABSL but by the VDC. You can turn that feature off.
To say it more precisely, an open differential will deliver equal amounts of torque to both sides.

This means it's important to understand torque - torque is a twisting or turning force.

For torque to be generated, there must be something to push against. If there is no resistance to turning a wheel, then very little torque is generated to turn the wheel - effectively none. With an open differential, the equal amount of torque is applied to the other wheel - effectively none.

That means that when one wheel leaves the ground or is in a zero traction situation, that wheel requires effectively zero torque to turn it. An open differential delivers exactly that amount of torque - effectively none - and it delivers that amount of torque to both sides.

Remember, to generate torque, there must be some resistance to turning or twisting.

Active Brake Limited Slip simply gives the open differential something to push against. When one wheel leaves the ground or is in a zero traction situation and begins to spin, ABLS will act to apply brake force to that wheel and that wheel only. To the open differential, this has the same effect as having traction with that wheel - there is now something to push against, allowing torque to be produced and delivered equally to both wheels.

Most reports of ABLS I've read indicate it works as designed. If, in fact, it *does* work as designed, it's the neatest thing since sliced bread. The driveability and low maintenance of an open differential with the traction of a limited slip differential. You get to have your cake and eat it, too.

That's how ABLS and open differentials work.



VDC is the system responsible for reducing engine output to limit wheelspin.

When you mash the gas and one rear wheel begins to spin (begins to lose traction), ABLS acts to apply brake force to that wheel - allowing the open differential to generate torque and be delivered equally to both wheels - giving torque back to the wheel with traction.

At this point, if both wheels spin and VDC is turned on, VDC will act to reduce engine output to reduce wheel spin. If VDC is turned off, you'll sit and spin both rear wheels.
 

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Austin said:
To say it more precisely, an open differential will deliver equal amounts of torque to both sides.

This means it's important to understand torque - torque is a twisting or turning force.

For torque to be generated, there must be something to push against. If there is no resistance to turning a wheel, then very little torque is generated to turn the wheel - effectively none. With an open differential, the equal amount of torque is applied to the other wheel - effectively none.

That means that when one wheel leaves the ground or is in a zero traction situation, that wheel requires effectively zero torque to turn it. An open differential delivers exactly that amount of torque - effectively none - and it delivers that amount of torque to both sides.

Remember, to generate torque, there must be some resistance to turning or twisting.

Active Brake Limited Slip simply gives the open differential something to push against. When one wheel leaves the ground or is in a zero traction situation and begins to spin, ABLS will act to apply brake force to that wheel and that wheel only. To the open differential, this has the same effect as having traction with that wheel - there is now something to push against, allowing torque to be produced and delivered equally to both wheels.

Most reports of ABLS I've read indicate it works as designed. If, in fact, it *does* work as designed, it's the neatest thing since sliced bread. The driveability and low maintenance of an open differential with the traction of a limited slip differential. You get to have your cake and eat it, too.

That's how ABLS and open differentials work.



VDC is the system responsible for reducing engine output to limit wheelspin.

When you mash the gas and one rear wheel begins to spin (begins to lose traction), ABLS acts to apply brake force to that wheel - allowing the open differential to generate torque and be delivered equally to both wheels - giving torque back to the wheel with traction.

At this point, if both wheels spin and VDC is turned on, VDC will act to reduce engine output to reduce wheel spin. If VDC is turned off, you'll sit and spin both rear wheels.

Great explanation!!! :cheers:
 

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Austin, thanks sooo much for clearing that up. I understood all the lingo and how these systems worked, but was never sure if the abls simply put the brakes on the wheel with no resistance and let the other spin, or applied some brake to make resitance equal and let both wheels spin. Now that i know both of my wheels will be spinning i am a happy camper. Thanks!
 

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Thanks for the info. If both rear wheels have no traction will ABLS brake both of them? Will it only do one side at a time?
 

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JS02 said:
If both rear wheels have no traction will ABLS brake both of them? Will it only do one side at a time?
As far as I can tell, ABLS will only brake one wheel - as soon as both rear wheels have equal traction (or equal lack of traction) and they're spinning at the same speed, ABLS is happy. ABLS on acts to limit relative movement on an axle - it's only function is to make sure the right rear tire spins the same speed as the left rear tire.

If you look at the pic below, you're told to turn the VDC off if you need to spin the rear wheels to unstick the truck.

 

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Austin said:
As far as I can tell, ABLS will only brake one wheel - as soon as both rear wheels have equal traction (or equal lack of traction) and they're spinning at the same speed, ABLS is happy. ABLS on acts to limit relative movement on an axle - it's only function is to make sure the right rear tire spins the same speed as the left rear tire.

If you look at the pic below, you're told to turn the VDC off if you need to spin the rear wheels to unstick the truck.
Very good!!! I was always trying to say that the ABSL system that Nissan uses is better than a plain LSD in some ways and works the same in others. This proves it. It is even better on the 4wd because it gives you the "posi" type system in the front also. (I think?).

Add the e-locker which you put on manual in situations where you know you will need it and this is a great set-up.
:cheers:
 

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keane said:
The ABLS uses features of the open difff to make it act exactly like a LSD.
Explain to me how it is acting like LSD?

The ABLS applies brakes to the spinning wheel so it stops spinning, thus transferring the power/torque over to the other side, in the hopes it can get grip.

An LSD would sense slip on one side, then engage the other side and then both sides would be powered and potentially getting grip.

How are these two the same? ABLS has retarded power to one wheel while the other one tries to get grip. LSD has not retarded power and has hooked both tires together so they can both try to get grip.
 

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Austin said:
As far as I can tell, ABLS will only brake one wheel - as soon as both rear wheels have equal traction (or equal lack of traction) and they're spinning at the same speed, ABLS is happy. ABLS on acts to limit relative movement on an axle - it's only function is to make sure the right rear tire spins the same speed as the left rear tire.
If this is really true, it would be great, and I will be more than happy to admit that ABLS might be an acceptable alternate to LSD.

The final test will be to see what happens when you turn off VDC and hammer the pedal. Do you get one black stripe or two?
 
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