Time to relocate LCA pivot point? pic

[Jersey]

Hey guys. I've been dealing with a bit of bumpsteer for a while and should really address the problem soon. I've read a bunch of posts about our front suspension (good reading from JohnC, TimZ and others HERE) and wondered if you think it's time for me to move the LCA PP's up a bit? I know it's real tough judging the relationship between the tie rods/rack/spindles/lower control arms from the pic angle and not being on-site but, i figured i'd just throw this one out there for some possible suggestions. Thanks.

 

[260DET]

If you would like more negative camber then move the inner point, up and out.

 

If not, try some 'bump steer' spacers. Either will put the roll center back somewhere near where it should be too, although that seems to be a bit of a contentious point.

 

It does not look too bad from the pic although the angle may be a bit deceiving, some bump steer and the Z go together

[Jersey]

Thanks Richard for the response. It's hard to tell but the LCA's are just about dead level. I'm not a real fan of those "bump steer spacers" from what i've heard and read. They just seem like bandades IMO.

 

Staring at the Z and this pic for a bit, i think i remember setting my toe slightly out a while back for better turn-in which may be adding to the issue as well. Thanks and funny comment... "some bump steer and the Z go together" That's why i i've delt with it for the last year or so! lol.

[rudypoochris]

Bumpsteer spacers would be the best solution in my opinon because

 

1. The will not alter the ride height of the car.

2. They will fix the control arm angles so that they point down, in turn letting you lower the car a little more with the correct LCA angles maintained.

3. It doesn't require machining.

4. They can be put on with out uninstalling the strut, lower control arm, or tension rod. Coil overs or a spring compressor would be required.

[johnc]

Number 1 and 2 are also true with respect to relocating the inner pivot.

 

IMHO, to properly drill the new holes, fill in the existing holes, and weld on the reinforcement washers the crossmember has to come out of the car.

[Jersey]

Thanks Rudy, John. I think i'll fight her until she comes off the road in a few weeks for the winter and do it then. I'm hoping to do a bunch of frame stengthening/welding/panel work so i'll be ripping her down enough to tackle this the right way, hopefully on a rotisserie. Appreciate the help and info.

[rudypoochris]

Thanks Rudy, John. I think i'll fight her until she comes off the road in a few weeks for the winter and do it then. I'm hoping to do a bunch of frame stengthening/welding/panel work so i'll be ripping her down enough to tackle this the right way, hopefully on a rotisserie. Appreciate the help and info.

 

A good idea might be to get the spacers and if you don't like them, just sell them. Also note they do come in different thicknesses so you don't have to go bananas. They really aren't difficult to install at all. Check it out. And np.

[rags]

Hi Len. I used the spacers on the red car and have no bad experiences. To really throw you a curve ball, this winter I'm gonna move the pivot up on the yellow car. I have a spare crossmember that I'm gonna use. Stop by and we'll see if we can fab a template.

 

Joe

[JMortensen]

Hi Len. I used the spacers on the red car and have no bad experiences. To really throw you a curve ball, this winter I'm gonna move the pivot up on the yellow car. I have a spare crossmember that I'm gonna use.

Just realize that running the spacer changes the amount that you need to raise the pivot. Even the standard, drill 3/4" up or 15/16" up isn't really exact. I run the spacer, and to eliminate the bumpsteer I slotted the hole in the crossmember then raised the pivot while checking the bumpsteer until I got it eliminated. Without some measuring you really can't do this job right (although it probably doesn't matter that much for a street car). Only takes a couple dial indicators with stands to measure and know for sure...

[jeromio]

This has been discussed before, in particular the fact that bumpsteer is not always bad. In other words, that geometry is there on purpose, for a reason. But in terms of eliminating it, due to the nature of the problem, the spacers are not able to fully "fix" it - they affect a different aspect of the geometry, the bumpsteer curve is altered, not eliminated.

Moving the pivot directly addresses the issue by moving those 2 lines closer to parallel.

 

I modded my car with the xmember in place, but yeah, it would be easier with it out. I recommend spot/tack welding the washer to the hole(s), so you'd need a welder.

 

Also, careful with moving the pivot out to increase camber. I did mine 1/4" out and camber changed quite a bit. I was also motivated by a desire to not hack up the LCA as much. As you move the pivot upwars, there is less room for the end of the arm to move, so moving it out helps (while also changing the suspension geometry).