What do we have from the factory for a diff? And why does everyone upgrade to the quaife lsd?

 

Stock comes with an open differential, in other words the wheel with least resistance is the one that rotates and the other may stay still, with an LSD both wheels will rotate equally.

 

but when you light em up... both wheels spin equally?

 

My 04 has always lit both tires up.. I'm pretty sure I don't have anything special in the diff. Quaif has never been on my mind

 

The ESP uses the brakes to apply pressure to the wheel that is spinning, thus transfering power to the opposite wheel. When that wheel starts spinning it does the same. So, in effect we have an electronic limited slip system. A mechanical locking system keeps one wheel from spinning from the start.

 

In dyno mode the ESP is not active and I still lay stripes for days, I also don't understand the benifit of the upgraded limited slip.

 

Straightline full grip

 

Quaife is full mechanical traction control..you will gain massive traction with this upgrade and ESP will not hold the car back under WOT

 

Exactly, you will not lay down as much "stripes" since both tires will turn and gain traction..well, you might but that's not the point... traction is improved.