Hi all

does anyone know how a torsen diff works say compared to a detroit locker?
Are the strong/ reliable or just another gimmick?

thanks

 

http://en.wikipedia.org/wiki/Torsen

 

had any experience with them?
our mechanic changed out the full spool and replaced it with one of these in our rally car...just trying to get a feel if that was a good or bad move
cheers

 

I like them, but they may not be the best depending on the car. Most of them are unloaded (Quaife, Detroit TruTrac), so if you have a wheel with zero traction (up in the air, or on ice) you are screwed. Faced with any other low traction problem they work great, smooth, very little friction loss, and no clutches to wear out like in a conventional LSD. I forget the name of the manufacturer but there are people out there making loaded torque biasing differentials that will work in a zero traction condition, some are even adjustable.

Peter

 

thanks!

I think the version we have is supposed to have a preload clutch to take care of the wheel-off situation (which is fairly common in our case).

the reliability question is one concern.
the other is that the diff applies torque from the inside wheel as it loses traction, to the outside wheel...which of course may cause it to lose traction!?!?

the article I read then followed this with..."This can lead to vastly changing cornering characteristics, and a torque sensitive differential requires expert driving skills to catch the change from enhanced outer rear traction to reduced outer rear traction to avoid rear oversteer."

So it sounds like it might bite one on the @$# if provoked!! ordinarily, this would be fun, but our roads are lined with very large trees that have a reputation for beating up cars and crews that come in contact with them.

I'd love to hear from anyone who has driven one hard on road or track

cheers

 

I've got a True-trac in my '66. Driven hard on the road, but not much muscle to really push it. Torsen is a true torque biasing differential, this allows it to distribute differing amounts of torque (within a narrow band). In my turbo 510 it was awesome. I've not tried a loaded torsen as I'm not into 4 wheeling or Ice racing.
What I personally like about the torsen is that I can't detect when it's coming in or out on a road course. It doesn't disturb the chassis at all. You can still steer with the throttle, you can still get understeer. It's really seamless. The other advantage is it doesn't get hot like a clutch style trac-lok. And it is very consistent.
As different manufactures seem to have differing levels of biasing, it pays to research and get the one that fits your car.
It's not a panacea, but it's pretty close in my opinion.
Really spend some time to find the right one for your application. It makes the difference between "awesome" and "OK".
***edit
In reading your last post, I've got to wonder if they had the right unit in their rear. Sounds like they had way too much biasing, and possibly incorrect preload for the car it was in. Properly set up it comes in as the inside tire is starting to unweight, not after it's all ready in the air. This kind of stuff is what bothers me about some of the crap you read. [:@] If they had that tough of a time, I've got to think something was wrong.
If the inside rear tire is off the ground, you are hard on the brakes in a tight turn. If you were on the gas, it would tend to hold the inside tire down, until the front or rear end breaks loose.
I've had my 510 with all 4 wheels off the ground over a rise a few times, no more issues on landing than if I had an open center dif. With the Torsen, I've had the front inside tire off a few times until I tweaked on the chassis a bit. The only times I've had the inside rear wheel off the ground have all been front wheel drive rental cars. I don't think any of them had Torsens though

You might try talking with some of the local racers to see what their thoughts are.

Good luck!,

Scott

 

thanks Scott
i think the comment was refering to a fairly early version and newer ones are far better

i'll try to find out what they've used

cheers