First of all, not including that you may have a aftermarket LSD I believe the old jack it up and spin a wheel does not tell you nothing.
Second I think the FTO's came with 2 diffs, a viscous LSD in the car of the year and early GPvR and then the facelift GPvR have a torque sensitive LSD. I know it is the diff mitsubishi Australia used the the Ralliart Magnas. Some info that I've found on this:
Manual Transmission
The big news for the manual transmission is the addition of a torque-sensitive limited slip differential (LSD).
As the 3.5 litre engine is one of the largest capacity FWDs, the LSD, combined with the grippy Pirellis, is considered a key factor in harnessing the performance gains achieved and elevating the driving wheels' adhesion-breaking torque to way beyond that of normal FWD or RWD passenger cars. A Limited Slip Differential was the logical choice for manual variants, while Mitsubishi's acclaimed Traction and Trace Control system is fitted to automatic variants.
The LSD selected is a torque sensing helical gear differential, as it:
-enables more powerful traction in response to accelerator fluctuations compared to a speed-sensitive viscous coupling type LSD,
-gives superior response to accelerator fluctuations compared to regular mechanical LSDs, and
-maintains drive even if one wheel experiences significant loss of traction.
The result is torque transfer to the road (even with different left/right wheel grip), even breakaway and the ability to accelerate hard from tight corners. The device gives up to 2.25 times torque difference between the driving wheels.
From: http://www.supercars.net/cars/2363.html
With this ability to transfer 2.25 times the torque to the wheel with the most traction I really don't think spinning a wheel when jacked up proves anything.
A little more info I've found is this:
The Torsen (from Torque Sensing) works as an open differential when the amount of torque going to each wheel is equal. As soon as one wheel starts to lose traction, the difference in torque causes the gears in the Torsen differential to bind together. The design of the gears in the differential determines the torque bias ratio. For instance, if a particular Torsen differential is designed with a 5:1 bias ratio, it is capable of applying up to five times more torque to the wheel that has good traction.
I've called a few gearbox specialists today who have sworn to me that what I am trying to describe as a Torque sensing LSD would be a mechanical diff and not viscous
And that without having the diff out there is no way to effective test the diff. They did confirm what I had always thought about having the car jacked up and spinning a wheel in that without any load on the diff this doesn't really prove anything.
For the record with my Version R in nuetral the other wheel spins in the opposite direction, when I gear the spin together but it is very hard to make them turn. (I think this is what I8AFRE was saying in AMACHA's thread) I'm not saying this is correct, my diff may be past it. I've never heard another version R owners experiences with this.
Despite that though I don't think this proves anything. The specialists told me that you can't really test anything with the diff without it out of the gearbox and on a bench, The only reccomendation they could give me was to find a bit of wet grass, one wheel on the grass, the other on the bitumen then pull away quickly, if the wheel on the grass spins and you go nowhere, it's an open diff. If you get good drive and pull away cleanly you've got a LSD
PLEASE NOTE. I don't reccommend doing this on a public road and you would be in big trouble with the police for doing this sort of thing on a public road, I take no responsibilty for anyone trying this and getting into trouble or breaking something.
.. But officer I was only trying to test my diff, I wasn't doing a burnout.........
In any case the reckon that it is fine for my application. Seems that it holds that the GL doesn't really seem to matter now days due to the additives that are added to prevent yellow metal damage which is the main difference between GL4 and GL5 oils.
