Models without LSD

[Sideways&Smiling]

Originally Posted by nikitopo

Here is a review from a magazine which mentions it almost right:

http://www.autosavant.com/2012/02/11...brz-ra-models/

"... the electronic limited slip diffrential which is replaced with a cheaper and lighter mechanically driven variant ... "

That is the first time I've ever seen anything saying the FR-S/BRZ/GT86 had an electronic diff...

[twag4]

Originally Posted by Tromatic

I wish it had manual windows, but that would be a no-go without the frame.

Why? My 1970 Chevelle had crank windows without a frame. Had rear side windows with no frame too. The two windows sealed to one another. If they could do it then, why not now

[rucfj159]

i love me a good lsd

[Sammakko]

Originally Posted by twag4

Why? My 1970 Chevelle had crank windows without a frame. Had rear side windows with no frame too. The two windows sealed to one another. If they could do it then, why not now

as did my both of my AW11's, and my '74 celica...

[nikitopo]

Originally Posted by Sideways&Smiling

That is the first time I've ever seen anything saying the FR-S/BRZ/GT86 had an electronic diff...

It means LSD together with the VDC. There is often a confusion. For example, clutch-type LSD is often referred as mechanical although Torsen is also a mechanical LSD.

[Sideways&Smiling]

Originally Posted by nikitopo

It means LSD together with the VDC. There is often a confusion. For example, clutch-type LSD is often referred as mechanical although Torsen is also a mechanical LSD.

Does the VDC even interact with the LSD at all? I thought it mostly interacts with braking? Pretty much everything I've ever heard about this car is that there are just 2 models..... Torsen LSD (like on the S2000, S15, etc.... pretty much every other modern sports car with an LSD from the factory) and an Open Differential on the RC stripper model. That's it... Are you saying there is another model?

[nikitopo]

Originally Posted by Sideways&Smiling

Pretty much everything I've ever heard about this car is that there are just 2 models..... Torsen LSD (like on the S2000, S15, etc.... pretty much every other modern sports car with an LSD from the factory) and an Open Differential on the RC stripper model. That's it... Are you saying there is another model?

That's what I'm trying to clear out. There was never a model with an open differential. The stripped down car offered a simple clutch-type differential. It is the same differential that is used in Lexus IS250 and it is usually referred as Semi-LSD. It is a simple implementation of a clutch type differential based on a spring (blue in picture):



Racing based clutch-type diffs use a more advanced locking mechanism.

[Sideways&Smiling]

Originally Posted by nikitopo

That's what I'm trying to clear out. There was never a model with an open differential. The stripped down car offered a simple clutch-type differential. It is the same differential that is used in Lexus IS250 and it is usually referred as Semi-LSD. It is a simple implementation of a clutch type differential based on a spring (blue in picture):



Racing based clutch-type diffs use a more advanced locking mechanism.

Interesting. Have never seen that before. I assume it's just a cheaper alternative that sits in between a viscous LSD and a Torsen in terms of effectiveness?

[nikitopo]

Originally Posted by Sideways&Smiling

Interesting. Have never seen that before. I assume it's just a cheaper alternative that sits in between a viscous LSD and a Torsen in terms of effectiveness?

There are two types of clutch types LSDs. The first is the one I mentioned with the preload mechanism and the other is the pressure ring based. You can see the differences here:

[ame="https://www.youtube.com/watch?v=WeLm7wHvdxQ"]Understanding Limited Slip Differential - YouTube[/ame]


[ame="https://www.youtube.com/watch?v=PEdnH7_7_yc"]Working of Limited Slip Differential - YouTube[/ame]


The pressure ring is more advanced because it gives you the option to choose between 1-way, 1.5 way or 2-way lock mechanisms and the locking force is bigger if for example we accelerate.

Overall, I wouldn't say that clutch types LSDs are in between of viscous and Torsen LSDs. Most of the racing teams use clutch type LSDs. I would say that the factory chose the Torsen LSD because of its limited maintenance cycle. Differentials are expensive to maintain and change and you cannot sell a mass production car with the clutch-based differential. An exception was made with the RC/RA models, but these count with less than 5% of the overall sales of the model.

[Packofcrows]

All fr-s have lsd.

Only ones who dont are in overseas market in Asia.

[Sideways&Smiling]

Originally Posted by nikitopo

There are two types of clutch types LSDs. The first is the one I mentioned with the preload mechanism and the other is the pressure ring based. You can see the differences here:

The pressure ring is more advanced because it gives you the option to choose between 1-way, 1.5 way or 2-way lock mechanisms and the locking force is bigger if for example we accelerate.

Overall, I wouldn't say that clutch types LSDs are in between of viscous and Torsen LSDs. Most of the racing teams use clutch type LSDs. I would say that the factory chose the Torsen LSD because of its limited maintenance cycle. Differentials are expensive to maintain and change and you cannot sell a mass production car with the clutch-based differential. An exception was made with the RC/RA models, but these count with less than 5% of the overall sales of the model.

I didn't mean all clutch-type LSDs, just those. It seems an odd choice considering they know most people buying the RC/RA models are going to buy a pressure ring based 1.5 or 2 way LSD. I guess they just decided to throw it in as an option instead of forcing a mandatory immediate LSD purchase like if they had included an open diff (although most buyers are going to do it anyway).

[acro]

Originally Posted by Packofcrows

All fr-s have lsd.

Only ones who dont are in overseas market in Asia.

Not only Asia but other markets as well. The earlier base automatic models in some areas had no lsd (that I know for sure). Iv heard that base manual versions also didn't have a lsd

[nikitopo]

Originally Posted by acro

Not only Asia but other markets as well. The earlier base automatic models in some areas had no lsd (that I know for sure). Iv heard that base manual versions also didn't have a lsd

Too bad if you missed the base manual version. This was the RC/RA model with minimal changes. In all the countries in Europe it was promoted as basic version, but it was the actual racing version. Unfortunately, you can buy it now only used. It was discontinued some months ago.

In general, there were some misconceptions about the base car. One thing was that it had open diff which is wrong. Only truth was that it didn't have a Torsen LSD. Another thing was that it had smaller brakes, but only few were aware that its brakes had bigger pistons. There were also other details like the absence of a floor silencer, of a trunk mat, of a car stereo and even an air-condition was an option. There were a lot of small details and decisions while the factory was trying to reduce the car's weight. You can find more here.

Anyway, too many things and we are getting a bit off topic.

[nikitopo]

Originally Posted by Sideways&Smiling

I didn't mean all clutch-type LSDs, just those. It seems an odd choice considering they know most people buying the RC/RA models are going to buy a pressure ring based 1.5 or 2 way LSD. I guess they just decided to throw it in as an option instead of forcing a mandatory immediate LSD purchase like if they had included an open diff (although most buyers are going to do it anyway).

It seems that you want to underestimate this type of LSD. Pressure ring based LSDs are good at acceleration or deccelation situations, but they don't lock on a constant speed. So, they won't lock until you reach the apex and after this point will start to lock progressively. On the contrary, a pre-loaded type LSD works differently. It will have a much weaker lock, but a stable one in the complete part of the corner. So, I would say that it is more a matter of choice and on driving style. Besides, our cars are not super strong on power. Higher cornerning speed is more important than hard decelerations and accelerations.