If you draw an imaginary line from the balljoint through the outer tie rod centers ,the meeting point from both sides would intersect at the rear axle center point for perfect akerman angle. That is what causes the inside wheel to turn more in a turn. In a front steer application the tie rod needs to be outside of the balljoint so when you would draw an imaginary line from the front tie rod center to the lower ball joint center it would intersect to the rear
Here is link to a good explaination of akerman
http://autorepair.about.com/gi/dyna...le_effect_on_ackerman_steering_principle.html
