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Discussion Starter · #1 ·
To preface, this is a brake function discussion. Not another AWD discussion!

I've read the entirety of the "GR-FOUR AWD System Discussion" as well as the entirety of the GR Yaris AWD discussion linked on post 44 within.

In that Yaris discussion there was an article shared which mentioned something that's not entirely clear whether they were referring to the power application, or brake intervention



Rectangle Font Machine Engineering Creative arts



That being said, I'm looking for information on the brake vectoring of this vehicle. More specifically brake vectoring during acceleration.

What I'm trying to find out is if the Core model without the torsen diffs will have the "E-lsd" or brake-activated traction assistance.

Basically, I'll probably never track the car. I need the AWD because where I live the roads are always wet, then of course there's 5 months of winter. Acceleration into traffic is annoying most days. So if this system is in place, for my personal use, there's no reason for me to have torsen diffs.

If anyone has caught an explanation elsewhere or in one of these videos and can share, I'd appreciate it!
 

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I think pretty much all modern cars in the US have traction control, including the GRC, which I think is pretty much doing what your're talking about. Applies brakes to a slipping wheel.
 

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To preface, this is a brake function discussion. Not another AWD discussion!

I've read the entirety of the "GR-FOUR AWD System Discussion" as well as the entirety of the GR Yaris AWD discussion linked on post 44 within.

In that Yaris discussion there was an article shared which mentioned something that's not entirely clear whether they were referring to the power application, or brake intervention



View attachment 2359


That being said, I'm looking for information on the brake vectoring of this vehicle. More specifically brake vectoring during acceleration.

What I'm trying to find out is if the Core model without the torsen diffs will have the "E-lsd" or brake-activated traction assistance.

Basically, I'll probably never track the car. I need the AWD because where I live the roads are always wet, then of course there's 5 months of winter. Acceleration into traffic is annoying most days. So if this system is in place, for my personal use, there's no reason for me to have torsen diffs.

If anyone has caught an explanation elsewhere or in one of these videos and can share, I'd appreciate it!
If you aren’t going to track it and it’s strictly a daily type thing, then getting the car without LSDs will save you cash.
 

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Discussion Starter · #4 ·
If you aren’t going to track it and it’s strictly a daily type thing, then getting the car without LSDs will save you cash.
I'm the technical type. I'm specifically after a video or article covering the stability system. So I'd love to see some data points on the system and the amount of involvement it has in various drive modes. Etc.

I figure I'll have to wait until the car is released for this type of data (if this type of data is released at all) and maybe even early next year when a few guys have driven them through a winter to get actual real world feedback on the matter, and what their findings are.

But I'm patient, so hopefully I'll get the information I'm after in a few months.
 

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I'm the technical type. I'm specifically after a video or article covering the stability system. So I'd love to see some data points on the system and the amount of involvement it has in various drive modes. Etc.

I figure I'll have to wait until the car is released for this type of data (if this type of data is released at all) and maybe even early next year when a few guys have driven them through a winter to get actual real world feedback on the matter, and what their findings are.

But I'm patient, so hopefully I'll get the information I'm after in a few months.
I tried doing some digging on the GR Yaris forums, but it almost seems like to be a member of the Yaris forums, you have to have LSDs. Lol
 

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Discussion Starter · #7 ·
@ryno9100 Thanks for putting some time into that! I didn't bother actually searching their forum beyond that topic because I would expect the Corolla to have a different stability control system than the Yaris, or at least different levels of involvement due to the size and weight differences between the two cars.
 

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Theres youtube videos of the GR Yaris and other awd cars (focus i think) on rollers showing how it handles 0 traction in various combinations
 

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Well Torsen diffs are not true LSDs. The don't limit the slip (ie Limited Slip Differential).

They are 'torque sensing' and split the torque. So the wheel with grip can get say 4 times the torque of the slipping wheel. But if the slipping wheel is in the air or on ice or on good rollers - 4 x 0 = 0.

You can apply braking to raise the minimum torque and transfer some over.

So in a scenario with one wheel on each axle with no friction a GR-C or GR-Y could get stuck. In the video you see there is some friction in the system, so it gets off on all the two roller cases. Even with three wheels on rollers they get off most of the time - there just isn't much torque getting the that one wheel.

BTW clutch pack LSDs have issues too, just different ones.
 

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Well Torsen diffs are not true LSDs. The don't limit the slip (ie Limited Slip Differential).

They are 'torque sensing' and split the torque. So the wheel with grip can get say 4 times the torque of the slipping wheel. But if the slipping wheel is in the air or on ice or on good rollers - 4 x 0 = 0.

You can apply braking to raise the minimum torque and transfer some over.

So in a scenario with one wheel on each axle with no friction a GR-C or GR-Y could get stuck. In the video you see there is some friction in the system, so it gets off on all the two roller cases. Even with three wheels on rollers they get off most of the time - there just isn't much torque getting the that one wheel.

BTW clutch pack LSDs have issues too, just different ones.
So I would like to see how a GRC without the LSDs would handle the rollers.
 
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