New Front Control Arm

[Neverdone]

Are any of these things you adjust often? If not, then why make them adjustable? Put them where the car handles best and hard mount them. 

[JMortensen]

Caster adjustments are useful and there are reasons to want more or less at a given time, or with particular tires, etc. Camber adjustments are too, but IMO they're better handled with plates on top, so that every camber change doesn't require a toe change.

[seattlejester]

I can see camber and toe depending on activity and or more practical reasons like street setting and race setting if you don't tow your car to the track.

 

I just haven't heard of adjusting caster very often. I guess because most cars don't have that option from the factor or aren't easily modified for it. I guess similarly if you change activities and run street tires vs road racing slicks or something of that nature a caster adjustment would be merited?

[JMortensen]

The more camber a tire likes, the more caster it will like, because caster gives you neg camber on the outside tire when you turn the wheel. This varies from tire to tire. Some tires like a lot less camber, like bias ply slicks, so they will like a lot less caster too.

[Mike Mileski]

Jon, if you look at the new arm assembly, the clevis that's at the frame attachment point for the TC rod will be mounted with the slot vertically oriented and it allows enough side-to-side movement of the standard rod end (not a solid eye rod end) to compensate for lengthening or shortening the TC rod. In fact, I did some calculations and, starting with the control arm pointing straight out from the car (90 degrees from the car), lengthening the TC rod a full inch, or shortening it an inch, only moves the TC rod about 1.5 degrees in either direction. With the clevis I'm using, the rod end can move about 5 degrees in either direction.

 

Mike Mileski

Tucson, AZ

[JMortensen]

When you add or subtract caster the problem is the LCA angle changes relative to the TC rod. It's not that the TC rod can't move at the heims joint, it's that the fixed stud that you've welded to the LCA won't allow for the LCA angle to change.

 

Made a crappy little picture to show the problem. Took the same image and rotated the LCA 5 degrees forward. You can see that the back of the TC rod is no longer in line with the frame rail. If you had a pivot in the front that could be locked down, then you could swing the TC rod back to the TC box. With a solid connection at the front there will only be one angle that works, no adjustability.

[Mike Mileski]

Oh crap! Back to the drawing board.

 

Mike Mileski

Tucson, AZ

[seattlejester]

Goodness I love the info here. Kind of glad I went off the shelf as I definitely wouldn't have considered all of this.