ToothDoc

So next year, I'm planning on doing an LSD swap. I'm just not sure if I should do a stock IS-F Torsen type or go with the OS-Giken.

For some reason, I just can't understand how the torsen works by looking at the pictures. I totally get the open differential and ball differentials. But until I get to open one and spin the axles, I just don't see it.

Anyways, it'll be for commute for 99% of the time and 1% of the time for actual road racing.

I've read that the clutch type can be very noisy etc. but OS-Giken for the IS-F is not like the typical clutch type.

Can anybody actually tell me a real advantage of one over the other? Lobux? Figs?

JrBully

iTrader: (1)

Subscribed! I'm also interested in knowing the difference between the two diff's. Pro's and con's.

NERD42

iTrader: (1)

Hmm... this is a very good question and hopefully a great explination.

lobuxracer

iTrader: (2)

A Torsen diff carrier has a torque bias ratio determined by the gearset inside the spool. What this means is, as long as both tires have some traction, you'll have torque going to both wheels - worst case will be the base TBR. All the clutch type LSDs don't depend on any traction on either wheel. They'll spin both wheels no matter what until the clutch is overcome by torque - either from the driveshaft or the axle. Where this really matters is when you are exiting a turn with the front corner fully loaded and the inside rear wheel off the ground. A Torsen diff is going to multiply the available torque based on the available traction. If the available traction is zero, you multiply the torque by zero and voila, it acts the same as an open diff. A clutch type does nothing of the sort. Even if one of the rear wheels comes off the ground, it will continue to send torque to the wheel with traction (hence the marketing term Posi-traction).

So - the clutch type requires maintenance and some require fiddling with friction modifiers in the diff oil to make them work acceptably. The Torsen requires nothing special at all and will last the life of the differential without issues. Pick your poison.

MisterSkiz

iTrader: (2)

I wonder if our "eLsd" would help the Torsen diff if the rear wheel comes totally unloaded off the ground by applying brake and therfore applying torque/traction.

ill let you guys know...I have a whole 2010 is f carrier im putting on my 08.

ToothDoc

Where did you get the 2010 diff? Junk yard? I might try to locate a junked 2010+ diff otherwise I'll just do OS-Giken.

Theoretically, the E-Diff should work in harmony with the Torsen diff. Good point!

lobuxracer

iTrader: (2)

This is definitely true. When I did the pedal dance at the track, I could get the inside wheel to spin mercilessly on the exit of turn 8. It sounds like a bad clutch, but it isn't. When I just turned off the VSC with the long push, this never happened.

darbs242

iTrader: (5)

Anyone try the cusco lsd's? they have a street, mild and race version of their lsd for the F. There is also the Toms LSD.... Reliable? Worth the cost over a junked torsion if you can find one

darbs242

iTrader: (5)

Is it just the initial setting up or is there a lot of maintenance and what is involved?

MisterSkiz

iTrader: (2)

The OEM Diffs in my 04/06 GTO's were Dana M80 Clutch pack Limited Slip.

When you changed the gear oil in them, you had to make sure you used the correct amount of slip modifier so that the the rear end wouldn't chatter at low speed turning maneuvers. People bought OEM Diff Oil and OEM Friction Modifier and followed directions to a T and still had problems with the rear end chattering, others guys did not.

When I changed mine out, I used Royal Purple in the rear end that came with "friction modifier" installed already and I had no issues.

As I understand it, the clutch type differentials are the most superior, with the trade off being:
1) that the clutches wear over time
2) fluid changes more often (worn clutch material in the fluid)
3) making sure you have the right mix of oem oil and friction modifier.

MisterSkiz

iTrader: (2)

a Salvage parts place in NY...from a 2010 IS-F that was damaged on delivery..part has basically no mileage on it.

darbs242

iTrader: (5)

^^^^ it's gone someone bought it a few days ago. I road course and drag race ofter... I'm thinking a clutch type is for me. But the low maintenance of factory is always nice

KJH

I can't speak to the OS Giken offering for the IS-F, but I have the OEM TORSEN diff in one Supra and the OS Giken Super Lock in the other. While the OS Giken is tuneable for the serious track addict, the "default" shim setting for the Supra is about perfect for the street, HPDEs and occasional serious track work. Lobux has explained the difference between the two. IMO, get the OSG and don't look back. In the interest of full disclosure, I am a BIG fan of OS Giken products. I have had their clutches in my Supras since 1998 and, this summer, installed the OS Giken Super Lock LSD in my red Supra. I will be doing the same thing with my black Supra as soon as I get some other projects out of the way.

ToothDoc

So I stared at the blow up picture of the OS-Giken and figured out how it works! Hahaha - just like a regular spider gear open differential. The plates are attached to the output gear and the casing alternating! There is a very thin space between the plates for a viscous oil to give the resistance to spinning. What I don't get is when they say it's forward only vs. braking, etc. Next up for learning.. Torsen and planetary types...Anybody have a good link with a blow up picture of those?

lobuxracer

iTrader: (2)

Click here for everything Torsen.