expansion does it give more?

[NINJADUDE]

expansion:
Does it give you just the plus 2 in STR and the plus 8 str from going up in size?

Size Increases
http://www.d20srd.org/srd/improvingMonsters.htm

expansion
http://www.d20srd.org/srd/psionic/powers/expansion.htm

[Karl Aegis]

It does exactly what it says it does. Nowhere in the power does it say you get 8 strength.

[Necroticplague]

Those size bonuses, by default, are only for what happens when you advance creatures by HD that they grow in size. You don't get them for Enlarge Person, or Expansion, or any other size-changing magic unless it says so. And Expansion doesn't say so, so you don't get it.