OldeSkool

My front alignment reading came out as...

Left ------------ Right
0.0 0.2 Camber
4.6 5.5 Caster
0.02 0.04 Toe
14.5 14.1 SAI


----- Front ----
-0.2 Cross Camber
-0.9 Cross Caster
0.4 Cross SAI
0.06 Total Toe

When someone reads off an alignment as "X Camber, Y Caster and Z Toe" are they referring to Cross XYZ or left/right XYZ?

Also, what would this alignment translate to? Tire wear, tracking and responsiveness?

Thanks!

TooSlow02

They would be referring to left/right measurements individually. From the looks of your alignment, you may feel a slight drift to the right, since you have more caster on the right. Cross measurements greater than 0.5 degrees may cause a pull. The camber is close to zero when the car is at rest, so the tires are almost perfectly perpendicular to the road. This may cause excessive outside shoulder wear if you take a lot of corners. If you drive on straight roads all the time, you won't notice any abnormal wear.

fast98

iTrader: (16)

acctually caster pulls to the most negative, so the pull would be to the left. camber will pull to the most positive. alot of people set there camber a lil positive so that when the car is loaded or in cornering the camber will be closer to zero. toe should be a lil negative on a rear wheel drive car because as u accerlate it will pull the tires out slightly. for road crown u will want a extra half degree of caster on the right, i use caster cause it is not a tire wearing angle, alot of people use camber which i think is wrong. your SAI steering axis inclination is non adjustable, but there is a spec for every car, if your car is out of spec it menas u have a bent control arm or frame or bad ball joint.good luck with your alignment

OldeSkool

Interesting. I was pulling slightly to the left, rotated my tires and started pulling slightly to the right... hmmm

fast98, do you think my SAI indicates a problem? Or does it look ok?

TooSlow02

Actually, caster causes a pull to the side with the higher value, which is never negative. It is not possible to set caster negative. In theory, if you could do so, it would make the steering so unstable that you couldn't drive the car. Caster is always positive on F-bodies. The pull caused by caster is due to the effect of the car's weight on the steering. Higher caster means that the steering axis leans back towards the rear of the car. The more lean in the steering axis, the more effect a downward force would have (i.e. the car's weight). As I said, you may feel a pull, you may not. Cross camber causes more of a pull than cross caster.

As for camber, it is set slightly positive from the factory. Depending on driving habits, the tires will wear faster on the outside shoulder. I set my camber negative so this doesn't happen. Also, during cornering you want the camber to be more negative, since the car leans over on the outside tire and makes it ride more on the outside shoulder of the tire. This is why front tires on f-bodies tend to wear faster in this area. Having static camber set negative can prevent dynamic camber from going positive.

Like caster, toe is the other way around as well. Negative toe means the tire points to the outside of the car (toe out), positive points inside (toe in). The spec for toe is +0.15 degrees, which means toe in. I set mine to zero, so my tires don't feather and cause a pull.

As for your pull, since you rotated tires and the pull changed direction the left hand pull was being caused by your tires. Did you rotate side to side or front to back? If you went side to side, the right hand pull is being caused by the tires. If you rotated front to back, the right hand pull might be due to the alignment.

TooSlow02

BTW you're SAI is fine.

fast98

iTrader: (16)

couple of things. caster pulls to the side that is most negative, or the numerically lower number. u can have negative caster on a f-body, i did a alignment on a 81 camaro the other day and it had -.08 degrees caster on the drivers side. as for the toe u are right i meant to say set the toe-in cause as a rear wheel drive car accelerates it will pull the tires out.

lil something about SAI for some people who didnt know
SAI is actually the difference between a true vertical line drawn through the center of the wheel and a imaginary line drawn through the upper and lower ball joints, or on a vehicle with struts, consider the upper strut mount as the loctaion of the upper ball joint. SAI ia actually a negative CAMBER angle of the steering axis. because the upper balljoint or strut mount will always be further inboard then the lower ball joint. SAI affects steering stability and wheel returnability much like caster does.
heres a picture for demo.

TooSlow02

Caster pulls to side with the higher (i.e. more positive) number. Hunter Engineering has some excellent information regarding alignments. Take a look at it. If you still aren't convinced, then someone better let Hunter's chassis engineers know how wrong they are. And I was assuming that we were discussing 4th gen F-bodies, not 2nd gen. So let me clarify- You can't set caster negative on 4th gen F-bodies.

fast98

iTrader: (16)

it seems we are both dead set on what we belive is right, i have some books i could put on here and maybe i will look for a little more info somewhere else, reliable info.

fast98

iTrader: (16)

http://www.familycar.com/alignment.htm

http://www.tweakyourcar.com/engine-repair/alignment.asp

go to either of these and scroll down to caster. i couldn't find anythign on hunters site about it, but either hunter's directions are wrong or u misread.

OldeSkool

Caster discrepencies aside... thanks for the info!