Can anyone explain the use of LSD(Type R) vs ATTS(Lude Type SH), my freind was asking me and I tried to explain to her but the more I said, the more it confused her as well as me.
What's the theroy behind LSD and ATTS? What's the simliarities and differences?

 

LSD uses actual physics of wheel slippage to lock the differential and transfer power. The ATTS is a computer controlled differential. Disadvantage of the ATTS is you feel the diff kick in more since its not a "natural" thing. Its also a very heavy tranny.

 

The two are different applications.
LSD limits slip of the wheels/tires under traction conditions.
ATTS is a system for driving the outside wheel in a turn up to 15% faster than the inside wheel, so as to aid in handling response (uses the vehicle wheel speed sensors), and does NOT provide an "LSD" function.

 

An LSD is a clutch-based differential intended to route power to both drive wheels when going straight, but have a limited amount of slip to allow the wheels to turn at different speeds while cornering. It's mainly useful in a straight line.

ATTS is an electronically controlled clutch-based differential intended to transfer more power to the outside wheel in a corner. It does relatively little good in a straight line.

Quaife and Torsen (stock ITR is a Torsen) differentials are gear-based designs that do both straight line power delivery and torque biasing in corners while being lighter and less complicated than ATTS.

 

So, let's said if I can doing a hard right hand turn with a heavy throttle, the LSD will actully let the outside wheel spin a little bit faster than the inside wheel? And what happens if the both wheels exist it's maximum traction and start to slip at a corner?

 

Well, the outside wheel has to turn faster on any corner since it is travelling a greater distance. The LSD was designed to let it do that, but unlike ATTS it does not actively bias torque to the outside wheel in a corner.

If both tires exceed their maximum grip both are going to spin.

 

Technically the ATTS is not a real LSD. Taking a hard right corner with foot on the gas, the outside left wheel will spin faster to, if traction is still there, increase turn in and allow you to make the turn understeer free. If you pass the tires maximum traction, your just gonna plow(understeer) till the tires grip again.

 

huh??
read this: http://auto.howstuffworks.com/differential8.htm
then return with any questions...

 

I have Never "felt" my ATTS kick in at all...except the car stops understeering and turn in is much improved...While driving the system is totally transparent.

 

i drove a Prelude with ATTS at an autocross. It seemed to lower the redline. I was blasting through a turn and I floored it. The ATTS kicked in and the tach would not go past 5500 or so. It was very weird.