Slotting rear upper control arms?

[KevinVarnes]

I scored some new to me rear upper control arms from the yunkyard today. The plan is to freshen these so they are ready to go in when I do all of the bushings in the rear of the '97. I will be running Vogtland 1" drop springs in the rear. I've never lowered any of my MN12's. Just haven't felt the need. I have read that sometimes the rear camber adjustment from the inner upper control arm bushing can be inadequate on these, especially on lowered cars. I was considering slightly slotting the upper control arm to knuckle bolt holes to get a little more camber adjustment. Not looking to go crazy here. Maybe 5/32" or so is probably more than enough.

Has anyone bothered doing this? Do we need more positive camber adjustment or more negative? I think we need more positive since I read about cars having tires tilted in after lowering it, but just wanted to confirm. Of course all of this will probably be moot since the alignment shop will tell me the rear isn't adjustable, but I do like to be prepared

 

[Wile E. Coyote]

I scored some new to me rear upper control arms from the yunkyard today. The plan is to freshen these so they are ready to go in when I do all of the bushings in the rear of the '97. I will be running Vogtland 1" drop springs in the rear. I've never lowered any of my MN12's. Just haven't felt the need. I have read that sometimes the rear camber adjustment from the inner upper control arm bushing can be inadequate on these, especially on lowered cars. I was considering slightly slotting the upper control arm to knuckle bolt holes to get a little more camber adjustment. Not looking to go crazy here. Maybe 5/32" or so is probably more than enough.

Has anyone bothered doing this? Do we need more positive camber adjustment or more negative? I think we need more positive since I read about cars having tires tilted in after lowering it, but just wanted to confirm. Of course all of this will probably be moot since the alignment shop will tell me the rear isn't adjustable, but I do like to be prepared

As a drifter, I found I was able to get 3° of total camber adjustment out of the stock bushings. So long as the arm wasn't bent (they bend btw), you should be able to make it work. And I was able to make the rear wheels have 0° camber after the car was lowered a few inches.

 

[KevinVarnes]

Interesting. So the arms bend more and make their effective length shorter? That makes sense. I've already spent too much money with Bill this year, so I'll have to go with the stock arms for now and hope they work.

 

[Wile E. Coyote]

Interesting. So the arms bend more and make their effective length shorter? That makes sense. I've already spent too much money with Bill this year, so I'll have to go with the stock arms for now and hope they work.

Yes. At a point the best I could do was -1.6 to make the rears even because the passenger side arm bent enough for that to be its max. But before the bend it was easy to make them within spec with the car lowered.

 

[XR7-4.6]

It takes like a 2” or more drop where the UCA camber adjustment runs out of range. I had no problem at all aligning the rear with 1” Vogtlands. Slotting things will just add complication to the process

 

[KevinVarnes]

Understand and that is why I asked. I don't want to get the car to the alignment shop and have them tell me they can't bring the rear camber into spec. My thought was to mildly slot them and torque them down in the factory position. If they call and tell me it's a no go I can let them know about the slotted arms and I/we have options.

I'll just leave them alone since it didn't look like the cars I got the arms from had been doing any Dukes of Hazzard style jumps like Wile E. Coyote apparently does and hope for the best.