Spools and diffentials
 

So ive been wanting to put a spool in the front of my tc5 since a lot of the setup sheets for outdoor asphalt drivers use spools in the front with a diff in the rear but really i dont know the difference between a spool and a diff can anyone help out. And what are the benefits between the two

Spool is a solid axle, diff is a differential.

To understand this, it is quite helpful to know how a differential in a 1:1 car works and why it is necessary. Here is a decent explanation including a movie of an open diff:
http://auto.howstuffworks.com/differential2.htm

A car requires the outside tire to rotate faster while turning to keep up with the inside tire. If this does not happen, then you will drag the outside tire around. However, because of this open diff, if one tire slips, then all of your power is being sent to that tire and not to the one with traction (because the slipping tire will spin easier).

A spool or locker will force the same amount of power to each tire. It negates the differentiation of the power that you see with an open diff. It is bad for turning, but good for forward motion. This is why I choose to lock the rear of my RCs and 1:1s and leave the fronts open.

I agree with Jeremy when he wrote the spool is bad for turning but good for forward motion.
As an experiment I replaced the one way in my RDX with a spool.The car pushed like a pig! I reinstalled the one way and put the spool in the rear.It felt like the car acclerated better.

If that is the case then why do people use spools? What does a slipper spool do vs. a spool?

A spool is used to put power down to the ground equally from both tires. Here is a picture of a buddy's jeep at a time when I locker/spool is needed:
http://www.texasoffroad.net/albums/m...1243.sized.jpg

You can see that the front Passenger tire is spinning and the front driver side tire is not. If he had that axle locked, then both would be turning and forward progress would have been made.

The same principle applies here.

Also, I have never hear of a "slipper spool"...