lower control arms

[travis steele]

What is the difference in one piece lower control arm compared to a two piece lower control arm.

[RacerX10]

What is the difference in one piece lower control arm compared to a two piece lower control arm.

Approximately (1) piece difference.

Full answer : no difference at all. The one piece unit is going to be a little easier to bolt on and set up, because the caster will already be in the ballpark for whatever the one piece part is meant for.

You could replicate the mounting points of a one piece unit with a two piece unit and end up in exactly the same place.

I'd also expect the 1 piece part to be somewhat stronger.

[tim15]

The one piece has better tie rod clearance.

[Matt49]

And tim15's first post is a winner :-)
Because of the "stud" on the back part of the two-piece lower, tie rod clearance was an issue. But adjust-ability (caster) is an issue with the one-piece lowers. This turn-buckle crap that builders are pushing makes me wanna puke. That's putting the entire system in a bind when you start stressing triangulated welded parts.
The upper is the best place to make caster adjustments because it has less impact on wheelbase (think about where the snout of the spindle is in comparison to the upper and lower ball joint).