probinator

Oklately my car was out of alignment, soI took it in and they stated that my rear was crooked and that I needed a camber kit and my rear adjusted. Here are my suspension mods.

Eibach pro kit.
Spohn adj. LCA's
Adj Panhard bar.

Now my steering wheel was off but now its fine and its still pulls to the right a little. Im taking it back but I want it to handle like on rails. What would be some good numbers to tell them to put it into spec?

Here are my specs now.

Front-left Front Right
-1.1* Camber -0.8*
7.9* Caster 7.7*
0.06* Toe 0.06*
16.2* SAI 16.5*
15.0* Included Angle 15.7*

FRONT
cross camber -0.3*
cross caster 0.3*
cross SAI-0.3*
total toe 0.12*

probinator

No one?

F1Fan

Hi probinator,

Alignment alone is not going to make your car with what you have installedonit"handle likeon rails." You don't have the right stuff to get where you want to go.

HTH!

probinator

I guess not handle like on rails. honestly I just go straight. but was wondering if there was a trick to the alighnment?

F1Fan

Hi probinator,

Oh, well to justgo in a straightline ignoring the unqual load on the front and rear axles when launching and the loss of grip due to lowering herearea fewsimple things you can do.

Set your Panhard bar to closely center the rear axleat static ride height knowing that you will have some level of squat at launch due to weight transfer. Using the body asa reference point for centering the rear axle is usually not veryaccurate. I measured and then punched a mark in the center of the diff to indicate the exact center of the axle and filled to diviotwith white paint. Then on a driveup alignment rack I simply measure the chassisfrom the diff centerline mark to the centers of the LCA's on the chassis side, whenboth sides are equal the axle is centered in the chassis.Next set your pinion angle, for a stock drive shaft this is pretty easy with an adjustable UCA and a bit less easy using LCA's to set pinion angle, on a drive onalignment rack just set the pinion angle to about -3 degrees (use -3 degress for your car withall poly LCA'sand stock UCA, for all poly UCA and LCA's use -2 degrees, for a car with solid ends use -1 degree),nose down relative to the rear driveshaft segment and then double and tripple checkthat your adjustable LCA's are PERFECTLY equal inlengthand confirmyour thrust angle is less than factory specs for alignment.

Fora dragoriented carI suggest minimizing fronttire dragby minimizing excessive toe changes when the car is running down the track. Obviously with a lowered chassis you willneed to buy a bumpsteer kitto correct your chassisbumpsteer issues. Ideally you want to set the bumpsteerkit's shims for minimal unfavorable (read toe-out) toe changes duringlaunch and when the chassis nose has settled back down during the runyou want the minimum amout of toe-in possible while still giving you a stable chassis at the top end of the run and transition to braking. Then you just need to get an alignment to confirm the setup is correct. It is pretty hard to find a shop that is knowledgeable in adjusting all of these features with aftermarket suspension componentsso if you are serious about alignmentit maypay to buy some tools to perform or at least verify reasonably close alignment to the specs you are aligning the chassis to.

For camber you just need to setcamber tostock factory settings and remember negative camber is your friend for corning but not your friend forbrakingstability. For a drag oriented car you want touse camberalignmentspecs as close to straight up as the factory alignment specs allow.

HTH!

Edit: Realize my coments are coming from a road course perspecitvenotdrag racing. My assumptions were that you wanta stable handling car as felt through the steeringwheel to the driver with a steady launch and transition to braking at the top end of the strip making certain that alignment is not the cause of the drift andthe rotational forces of the drivetrain would be handled using appropriate additional suspension hardware. Also I assume you would preferstability not come at the expense ofdrag caused by thefront tires which can be considerable.

Norm Peterson

What were the rear wheel readings? You should at least have a thrust angle for the whole axle and individual rear toe readings. Maybe even rear cambers as well.

Even without that information, I think it would drive a little better if the front cambers were set equal and those caster angle values swapped left to right. With unequal caster (cross-caster not equal to zero) the car will tend to drift toward the side with the smaller positive (or more negative) caster setting. And camber thrust pushes away from the side with the more negative (or less positive) setting. Either the right side a little more negative on the camber or a little more positive on the caster are typical ways of compensating for road crown (which tends to have you drifting downhill to the right). Right now, you've got both of those alignment settings working with road crown to make the car go to the right. IMO, equal cambers and setting a little cross-caster is the better fix.


Norm

F1Fan

Hi probinator,

I'm sorry, my comments were focused on a level surface like a race track and did not address road crown. If you are talking about street use Nornisright on the alignment, zero out your camber side to sideeven if it means giving up some negative camber, the difference is slight for a non-handling oriented car. The caster is sort of adjustable by twiddling the strut mounts in the sloppy factory holes, it takes a few extra minutes but you only need a small change in caster so it should be achivable without cutting or grinding any sheetmetal.

HTH!

Norm Peterson

It's possible that the front subframe has shifted slightly, perhaps both laterally and rotationally. I was just sent a link to this memo. Although it's for a completely different vehicle, it does a pretty good job of explaining another possibility.

Norm

bchataroo

On the pinion subject:I have combo LCA's, poly/poly panhard bar, stock UCA, stock shaft, and Eibach Prokit. My pinion angle is between 2.5 and 3 degrees. Will this be enough angle to cause vibs at 90ish mph?

Thanks

chupac

The only thing I would change is the camber on the left front tire, I would set it at -.5, reset the toe,and I could guarantee that it would drive straight, and handle better.