*(if you have a female Blaziken with Speed Boost)
> Starting in Black 2 and White 2, there is an 80% chance that the Ability slot of the female will be passed to the baby. For example, when breeding a female Pinsir with Hyper Cutter, the resultant Pinsir has an 80% chance of having Hyper Cutter rather than Mold Breaker. This chance does not apply if Ditto is used as either parent.
So, to breed a Torchic with Speed Boost in White 2 you simply have to breed your female Torchic (or one of it's evolutions) with something in it's egg group. The Torchic, Combusken, or Blaziken must be female or you cannot pass down the ability.