Originally Posted by FIGS

Its a fairly large difference between the OSGiken TCD and the Factory LSD. The factory uses a Torsen type which requires a large slip event to engage or a certain number of slip revolutions to engage the other axle and at that the other axle is only splitting torque the with the gripping axle by some ratio. If one wheel loses traction completely then 0 torque is transferred to the other wheel. It also only takes the input torque and divides it, so it does not work under coast conditions.


I also found this handly animation
Diferencial Torsen (Autoblocante) / Self-locking Torsen Differential - YouTube

The OSGiken TCD uses a multi element clutch type engagement with a conical washer and splined gears to apply more and more loading to the elements.



This means that it will allow full 100% locking of both axles at the terminal torque of the loading mechanism. This is a much more progressive lock feel and has more impact in a corner because it gives you a stronger vector through the corner. The driving sensation is that you are being pulled through the corner with the gas pedal vs sliding to the outside gradually with an open diff and simply holding with a Torsen. The point at which the full lock occurs is tunable and the TCD type for the IS-F has through holes in the clutch plates to damp noise and smooth the function quite a bit. I have never felt a "hit" when full lock occurs which does happen on some of the superlock LSD's apparently.

The other thing is that the OSGiken is 2-way, meaning under acceleration and braking the clutch is working. I feel that engine braking with the F transmission is much more effective and stable with the change. Though our car is pretty neatly tuned in other suspension areas so it would hard to give a perspective on a purely stock vehicle.

Hope this helps.
Mike

Originally Posted by MileHIFcar

Thanks for the link and post. I see you added it to your IS350, was the difference noticeable immediately?

Originally Posted by Biggu

MileHIFcar, I am waiting on an ATS Carbon LSD to be sent to me for testing purposes as well. Its price point is lower than the OS Giken and should be just as good or the same.

Originally Posted by redspencer

Without a doubt. The best way to describe the difference is to think of the OS Giken TCD as a mechanical torque vectoring differential but without an ECU to dictate how much torque should be applied to the outside rear wheel while cornering. You simply apply more power via the gas pedal in order to progressively add more torque to the outside rear wheel which will help steer your car around the corners and have a high corner-exit speed while maintaining outstanding traction and stability.

Originally Posted by MileHIFcar

That's sounds like the way the IS F should have been from the factory I wonder why Lexus/Toyota went with an E-LSD for 2008/09 Trying to save a buck??

Originally Posted by SpeedFreaksUSA

We can put together a group buy for OS Giken units if there are a couple people interested

-Matt M.

Originally Posted by torxuvin

Count me in if we can get it for the right price. It should be interesting to see how the ATS does

Originally Posted by SpeedFreaksUSA

Perhaps one of the largest benefits of the OS Giken LSD unit compared to the the factory torsen and other competitors is the durability.

Originally Posted by 93MSB

Wouldn't the factory torsen be more durable, or maybe I should say last longer? It does not have clutches that wear out and eventually need replacing.

Originally Posted by SpeedFreaksUSA

Thank you redspencer for posting that. FIGS's did a nice job of explaining the differences. The only thing I want to correct is that the standard version of the OSG is a 1.5-way, not a 2-way. However, it can be configured as a 1.1-way or 2-way if the user wants. Perhaps one of the largest benefits of the OS Giken LSD unit compared to the the factory torsen and other competitors is the durability.

We can put together a group buy for OS Giken units if there are a couple people interested

-Matt M.