Torsen or plated LSD for circuit/hillclimb etc?
I have a Modena Torsen style LSD available but some recommend a plated.
what are your views?

Torsen

any chance on expanding on this topic for those of us that dont understand.

What is the differences and what are the advantages of each type for what situation?

would be an interesting thing for those of us that have not yet tackled diffs and are wanting to get into a bit of motorsport.


Anthony

Basically :

The "plate" style LSD uses friction plates or clutches inside it that under load basically end up locking together gradually,but always putting power to both wheels at the same time.
You can set the "slip to grip" ratio by the amount of preload on the diff.

Advantages? Have some sort of friction even under off throttle conditions, so they are very good for high speed racing, say turn one at Eastern Creek.
Disadvantages? more of an opportunity to understeer in low speed corners, but you can tune it out with some work!

Here's an exploded view of a ZF unit.

http://www.alfabb.com/bb/forums/showthread.php?postid=33954#poststop 



The "Torsen' style LSD uses a series of gears inside it to provide the lock up. The difference here is, because the way the gears mesh against the drive axles, it can feel which of the two wheels has the most grip and therefore the power is directed to that wheel.
Advantages? The difference here is that under normal driving conditions and off throttle situations, the diff acts like a non-LSD diff, making cornering easier.
Disadvantages? Only thing I could think of is if you backed off at high speed (say 160kmh) into a corner and you had no form of friction braking other than the engine, it might snap out at the rear of the car and increase the pendulum effect.

Not sure on that one, you'd have to ask someone who has one and races it, I've only got a ZF..... Craig?

One common theme between both styles....
"They're expensive!!!!"

Here's a torsen link

http://www.quaifeusa.com 

The Torsen under high lateral loads (and under acceleration) can "unlock".

U2U debiasi4 (drag racing section) about the one he uses in his hillclimb car and drag car. Very strong, never heard of either of these problems happening but I'm not an expert.
T54

Well the new diff is ordered from Stuart Wilkins Rallying here in Sydney. Kaaz 1.5 way plated.
$1470 to my door, price in the US was $880USD!!! so I think it's kinda OK....
so now I need.....

Check list...
spare gearbox................check
sprare axles....................check
spare CVs......................check
No real meat for 12 weeks to pay for it.........check

ive always heard that the clutch pack type lsds were the best for track..... porsche tried the torsion diff, but quickly went back to the clutch type.

was the LSD for a IRS or swing axle?

The LSD was for a Subaru gearbox.

Just some follow up. I've had the KAAZ LSD (plated) in for a couple of weeks now, after "running in" the diff doing figure 8s in the car park at Wakefield Park I hit the track for some laps. I found the car to be transformed and so much easier to drive. When power is applied getting out of the corner the car sits down and just powers out instead of smoking a wheel as it used to do.:P very happy with the performace........just a problem with the poor old clutch now, seems hooking up 2 rear wheels at a time was just too much for it. New one being installed tomorrow....I've also found it to be VERY noisy, I hope that it's not the way I assembled it when I had to fit the output stubs? :P

Hi Peter,

I saw the Buladelah (I'll never spell it right) Hillclimb DVD and you are Mr Squiggle. You come out of the corner put your foot down and leave a black line with your left rear and back off slightly for the left hander then put your boot in again and leave another line with the right rear tyre. How's your pulse rate?

Very cool.

CYA CT