Educate me on the ES differential
02-10-13, 06:49 PM
#1
Educate me on the ES differential
I got stuck in the snow yesterday, while getting out of the garage - decided to plow through a foot of snow.... I noticed something interesting while trying to get out of it. Keep in mind that my car is riding on Michelin X-Ice tires, which are supposed to be good in the snow. What I noticed is that my driver side wheel was on pavement, and the passenger wheel was on an inch or two of packed snow. Even though the left tire had traction, all the power was going to the right wheel, which kept it spinning and not moving the car.
Is this a result of an open differential? The power travels the path of least resistance? What do modern cars have that prevents this from happening, if anything? I've heard of limited slip differentials, and upon a brief Google search, I realized that they can help in such situations, but can also be twitchy in low traction conditions.
Is this a result of an open differential? The power travels the path of least resistance? What do modern cars have that prevents this from happening, if anything? I've heard of limited slip differentials, and upon a brief Google search, I realized that they can help in such situations, but can also be twitchy in low traction conditions.
02-10-13, 08:12 PM
#3
I got stuck in the snow yesterday, while getting out of the garage - decided to plow through a foot of snow.... I noticed something interesting while trying to get out of it. Keep in mind that my car is riding on Michelin X-Ice tires, which are supposed to be good in the snow. What I noticed is that my driver side wheel was on pavement, and the passenger wheel was on an inch or two of packed snow. Even though the left tire had traction, all the power was going to the right wheel, which kept it spinning and not moving the car.
Is this a result of an open differential? The power travels the path of least resistance? What do modern cars have that prevents this from happening, if anything? I've heard of limited slip differentials, and upon a brief Google search, I realized that they can help in such situations, but can also be twitchy in low traction conditions.
Is this a result of an open differential? The power travels the path of least resistance? What do modern cars have that prevents this from happening, if anything? I've heard of limited slip differentials, and upon a brief Google search, I realized that they can help in such situations, but can also be twitchy in low traction conditions.
02-10-13, 08:36 PM
#4
Lead Lap
Great video. The action of a differential is a very misunderstood topic and debates rage on daily on any AWD/4WD slanted enthusiast forum. One critique I have, and not really about the video, it is his topic, but the idea of a "locked" differential that is not something that you would use in a street car. Off roading, drag cars sure but not a street car. Just keep in mind the "solution" so to speak to the open differential is a class of devices commonly termed a Limited Slip Differential. There are dozens of different designs that are each their own topic.
The Lexus ES is a very basic drivetrain and as you have guessed it is a simple open differential. Does your Lexus have traction control? In addition to the throttle limiting this feature brakes the slipping wheel, which does provide LSD action. I got to test this after the Blizzard yesterday on my 01, it works pretty well on snow, I am on similar or same tires (the latest version 3 of the X-Ice).
Here is an outstanding video, done by GM in the 30s, takes you back to the question "why do you need a differential" and then walks you literally through how it works. I knew how a diff worked but this really gives you the visualization.
LSDs do have to be carefully chosen for front drive wheels. Viscous or Torque Biasing type work well, I had the Quaife ATB type stock one in my SRT-4 and it worked well no odd noises.
The Lexus ES is a very basic drivetrain and as you have guessed it is a simple open differential. Does your Lexus have traction control? In addition to the throttle limiting this feature brakes the slipping wheel, which does provide LSD action. I got to test this after the Blizzard yesterday on my 01, it works pretty well on snow, I am on similar or same tires (the latest version 3 of the X-Ice).
Here is an outstanding video, done by GM in the 30s, takes you back to the question "why do you need a differential" and then walks you literally through how it works. I knew how a diff worked but this really gives you the visualization.
LSDs do have to be carefully chosen for front drive wheels. Viscous or Torque Biasing type work well, I had the Quaife ATB type stock one in my SRT-4 and it worked well no odd noises.
02-10-13, 09:43 PM
#5
Great video. The action of a differential is a very misunderstood topic and debates rage on daily on any AWD/4WD slanted enthusiast forum. One critique I have, and not really about the video, it is his topic, but the idea of a "locked" differential that is not something that you would use in a street car. Off roading, drag cars sure but not a street car. Just keep in mind the "solution" so to speak to the open differential is a class of devices commonly termed a Limited Slip Differential. There are dozens of different designs that are each their own topic.
The Lexus ES is a very basic drivetrain and as you have guessed it is a simple open differential. Does your Lexus have traction control? In addition to the throttle limiting this feature brakes the slipping wheel, which does provide LSD action. I got to test this after the Blizzard yesterday on my 01, it works pretty well on snow, I am on similar or same tires (the latest version 3 of the X-Ice).
Here is an outstanding video, done by GM in the 30s, takes you back to the question "why do you need a differential" and then walks you literally through how it works. I knew how a diff worked but this really gives you the visualization.
How a differential works
LSDs do have to be carefully chosen for front drive wheels. Viscous or Torque Biasing type work well, I had the Quaife ATB type stock one in my SRT-4 and it worked well no odd noises.
The Lexus ES is a very basic drivetrain and as you have guessed it is a simple open differential. Does your Lexus have traction control? In addition to the throttle limiting this feature brakes the slipping wheel, which does provide LSD action. I got to test this after the Blizzard yesterday on my 01, it works pretty well on snow, I am on similar or same tires (the latest version 3 of the X-Ice).
Here is an outstanding video, done by GM in the 30s, takes you back to the question "why do you need a differential" and then walks you literally through how it works. I knew how a diff worked but this really gives you the visualization.
How a differential works
LSDs do have to be carefully chosen for front drive wheels. Viscous or Torque Biasing type work well, I had the Quaife ATB type stock one in my SRT-4 and it worked well no odd noises.
Question - why don't they make a lockable diff for 2WD cars? Is an LSD good enough, where such a feature wouldn't be needed? It would be nice to be able to lock the diff when you're stuck in snow, gravel, or mud.
I do have Traction Control, but it wasn't activating in that instance for some reason. I just kind of gunned it back and forth, and shoveled around the tires a bit.
02-11-13, 07:48 AM
#6
Lead Lap
I think expense and driver competence are the biggest reasons why there are not LSD or lockable diffs in non-performance/off-road cars. If consumers don't demand a sort of capability or features it won't be put in the car since making automobiles is an extremely price competititive business. A lockable diff would be neat, of course most people wouldn't know you should only drive straight with it engaged. Most people in North America don't encounter ice and snow all that often either. Even here in Boston I might drive on snowy roads a few days a year on average. Anyone who cares here just buys an SUV.
Technology has supplanted this, the traction control system can give you maybe 50% of the effect of an LSD, and in some cases can work better. In a car that has ABS, all that needs to be added to give traction and/or stability control now is a couple more sensors and some software code, it is very cost effective to add and now required equipment for new cars, so we have that.
I too noticed the traction control system seems to let you spin a bit before it intervenes, much different than if you floor it from a stop on dry or wet pavement the fuel cut shuts you right down. Perhaps that is a sort of "snow program" working. I found if you stay on the throttle moderately and let the light flash while it does its thing, it worked best getting started on snow. The braking action transfers torque from side to side, as you now know from watching that video you posted, the open diff is 50/50 so if you brake the slipping side you increase the torque required to turn it and therefore allow more torque to the side with traction.
Technology has supplanted this, the traction control system can give you maybe 50% of the effect of an LSD, and in some cases can work better. In a car that has ABS, all that needs to be added to give traction and/or stability control now is a couple more sensors and some software code, it is very cost effective to add and now required equipment for new cars, so we have that.
I too noticed the traction control system seems to let you spin a bit before it intervenes, much different than if you floor it from a stop on dry or wet pavement the fuel cut shuts you right down. Perhaps that is a sort of "snow program" working. I found if you stay on the throttle moderately and let the light flash while it does its thing, it worked best getting started on snow. The braking action transfers torque from side to side, as you now know from watching that video you posted, the open diff is 50/50 so if you brake the slipping side you increase the torque required to turn it and therefore allow more torque to the side with traction.
02-11-13, 09:39 AM
#7
Lexus Test Driver
I have an aftermarket clutch-type LSD on my MR2. I believe Skyline also has such LSD. And I can tell you they are not that comfortable when turning because of the clunking noise...especially for average driving.
Thread
Thread Starter
Forum
Replies
Last Post
HPvsMPG
ES - 1st to 4th Gen (1990-2006)
5
02-13-16 05:46 PM