Rear control arms - odd movement

[LateFan]

Suspension experts, I have a question...

If the rear suspension does a funny sideways lateral movement when doing the upward movement (the "hop") over a bump, does that imply a bent control arm?

Background info:
Father-son project '86 ES. H&R sport springs. All new OEM rubber subframe and control arm bushings. Stock generic shocks so far. Has eaten a set of new rear tires in 8000 miles due to camber and toe(?). Toe is close to equal left to right - I thought that would reveal a bent arm.

No lateral movement that I can tell on compression, it's when it hops up. It was very pronounced when we bought it cheap and a bit worn out. Much less now, but still there sometimes.

[rturbo 930]

Have you had an alignment done? How bad is it?

Asking because my rear end is pretty wonky, so this discussion may be relevant to my interests.

[LateFan]

I got to drive it this weekend, about 400 miles on 2-lane highway.

Ya know......mayyybe I'm blaming the wrong end... The rear trailing arms obviously need adjustable mounts for toe and camber, but the left to right numbers are the same, so is anything bent?

I tried to pay attention to how it was acting. Sadly, these were very smooth roads! The only time I've every complained about smooth roads!

But on compression through a dip, it wants to steer right. It pulls the wheel. It self-corrects right away. More annoying than dangerous. It did this before we rebuilt the suspension, far worse.

On rebound / unweighting / over a hump, it wants to steer slightly left. So that's where the "wiggle" I was feeling is coming from I think - when you hit a dip then unweight. When you go over a hump and then compress on the other side.

We've had it aligned a couple of times, first when we did all the bushings and springs, and checked again after the rear tires wore out.

Again, it's an '86 ES coupe with H&R Sport springs, E90 drop hats in front, generic shocks, rebuilt E36 steering rack, all new rubber bushings, and new tie rod ends.

Numbers, Front -
Caster left: 8.96º
Caster right: 8.47

Camber left: -1.89
Camber right: -2.13

Toe left: .22
Toe right: .14


Rear -
Camber left: -2.79
Camber right: -2.68

Toe left: .42
Toe right: .61


So do any of these numbers point to a pull to one side or a tracking issue?

How does front negative camber and ride height affect caster, steering angle, roll center etc etc?

Something's off a bit, I can't tell what.

[LateFan]

We pulled the subframe to weld on IE adjustable TA tabs. I don't see any bends or cracks on the TA's. Don't have the right dowel yet, but eyeballing through the TA holes with a light, they look to line up fine.

[kronus]

you won't be able to spot a bent TA by eyeballing the TAB holes. They bend at the big cast thing that holds the bearing.

I've also had somewhat analogous symptoms when using tires with very uneven shoulder wear L/R. (after a long counterclockwise track day)

[LateFan]

Wow, at that big heavy end? I assumed it was those dainty little arms!

If I plan to set camber at say -1.5 with these H&R sport springs for a street car, is that right? My alignment shop printout says -1.33 to -2.33. I'd be half of the almost -3 now. 1.5º makes that kind of difference?

Although when I look at our toe numbers, we're at 2 to 3 times the max spec toe now. So a bit too much negative camber and a lot of toe is going to scrub tires.

Do people set their camber at the end closest to min, -1.33, if they anticipate a lot of loaded down long trips?