Okay, I was told at the LHS that if I wanted my diff to be tighter I should use OFNA 120,000wt oil in it. I don't know if your cars have a ball diff, the same effect of tightening the diff.

http://www.traxxas.com/products/nitr...to_details.htm

"Sealed Limited Slip Differential
The sealed limited slip gear differential can be precisely tuned with lighter or heavier lube for maximizing rear traction and cornering performance. "
-Jato details

So where do I get this heavier lube? Should I use the OFNA fluid? I don't want to lock the diff but I want it to be rather tight.

As far as 'unloads' I mean that all the spin goes to the inside tire too easily, for instance, picture this, you are on a thick lawn doing about 20mph and as you accelerate out of the turn the inside tire suddenly gets all the torque and loses traction, spins hence spinning madly. On dirt this would result in an easy spin out.