Mounting pull up bar on cinder block wall
The problem can be divided into 3 parts:

A) Determine the static pull-out force.

B) Determine the dynamic to static force ratio. My gut feel is 2X to 3X, but I have nothing to back it up.

C) Determine the appropriate fasteners and/or additional interface.

This is only an answer to part A.

The problem is much easier to solve if a few simplifications are made. I have re-positioned the diagonal, this is OK because we don't care about the compression force in the diagonal member. Each member can now be considered to be a strut of a simple truss (tension or compression only, no torque). 

The geometry determines the forces. The static pull-out force at the top is the weight of the person multiplied by the ratio of the dimensions (projection/vertical).

250 lbs * 30"/24" = 312 lbs