Wheel Centering + Alignment Woes

[kyngfish]

Alright - so this problem started when I installed my turbo tie rods. But essentially I've got a few compound issues and I'm trying to figure out what's up.

1986 3.2 Carrera running 7s, and 8s.

First thing I did when I got the turbo tie rods on is center the steering wheel. My wheel does 3 total turns from lock to lock, so I figured that means my "center" is at 1.5 turns. It was slightly off, so I rotated one spline clockwise and that put my wheel at center.

Then I raised the car up to take the weight off the wheels, centered the wheel, put the car back down, and set up a string box around my car. Roughly, the track at the rear was 2 cm (1 cm on either side) deeper on the rear than the front, I would have expected the rear to be wider (shallower measurement), but I'm guessing the track is based on wheel offset, rather than the hub. (Also I'm measuring from the center of my BBS with the caps on, rather than the end of the axle, which maybe I shouldnt do)

With wheel centered, I am getting the following alignment measurements from wheel edge to wheel edge.

REAR PASS - 3.5mm toe IN REAR DRIVER - 5mm toe IN = overall 1.5mm toe IN to the right

FR PASS - 3mm toe OUT FR DRIVER - 5mm toe OUT = overall 2mm toe OUT to the left

I want to dial it in a bit more, but this is about the 100th adjustment and a few things are always happening :

1. The steering wheel ALWAYS wants to settle with the bottom of the "Y" on the momo steering wheel at 6:30 - 7 o'clock instead of 6 o clock, irrespective of which side of the crown of the road I am on - so the wheel always wants me to sit as if i were turning slightly to the right
2. The car is consistently pulling right, again, irrespective of the crown of the road.

So my question is, if my alignments are right, then if during driving if the wheel "wants" to sit slightly turned right, of course it will pull right, but if I force the wheel to center, the car turns to the left, where the toe measurements would suggest it should pull right.

Will someone smarter than me tell me where I'm messing this up?

[kyngfish]

Neglected to add:

CAMBER :

REAR PASS - -2.1deg. REAR DRIVER - -2.6deg

FR PASS - -0.3deg. FR DRIVER - -0.5deg

[stownsen914]

Those toe measurements are pretty large, and leave me wondering if they’re just not correct. What are your reference points to come up with those measurements? String along the side of the car? Perhaps yin can describe your process briefly, namely how you confirm the strings are parallel and that the car is centered between them.

[kyngfish]

Originally Posted by stownsen914

Those toe measurements are pretty large, and leave me wondering if they’re just not correct. What are your reference points to come up with those measurements? String along the side of the car? Perhaps yin can describe your process briefly, namely how you confirm the strings are parallel and that the car is centered between them.

3mm = 1/8 inch give or take, I didn't take them to be that huge, but good to know if I'm wrong.

Here's how I go about it, I have 2 equal sized tubes on the front and back of the car on jack stands, they've got measurements on the ends, basically I put the string on the 3 inch mark (three inches in from the end) on all sides of the tubes, so if the strings are equal distances from each other on the tubes, they should be parallel. Then I fiddle with the tubes until I am getting a matched measurement on either side of the car from the center of the wheel to the string. in this case, I am getting roughly 9.1 cm from wheel center to string in the back, and 8cm in the front.

I've done several adjustments and take notes each time, it's usually always within 2mm from center to string for those front and back measurements.

From there i measure the lip of the rim on the front and back of each wheel to the string. In this case

6.2CM 6.1cm
REAR
9.05CM
6.55CM 6.6cm

Passenger. Driver.

8.0CM 8.2cm
FRONT
7.95CM
7.7CM 7.7cm

Where I might be getting messed up is that my jack stands are different heights, so although it's close, the string doesn't quite pass the center of the wheel, so I have to eyeball some measurements from a longer distance than I would like.

I'm sick of messing with the jack stands anyway, and I've gone ahead and ordered the BG racing kit that mounts on the car, should be here tomorrow.

[kyngfish]

I formatted the numbers differently in my post there to make it clearer which are the passenger and driver measurements, and which are front and back of wheel. but it didn't keep the formatting, hopefully you can make sense of it though.

[nickelplated5s]

Take it to AnP in Portland for an alignment. They, you can say to them, did my white 911 after a front rebuild. Al had to customize some fittings from ER to get the camber correct.

It's going to be wet Sunday so my car will stay home from the PIR AX. I paid so will show early if you decide to come.

[kyngfish]

Originally Posted by nickelplated5s

Take it to AnP in Portland for an alignment. They, you can say to them, did my white 911 after a front rebuild. Al had to customize some fittings from ER to get the camber correct.

It's going to be wet Sunday so my car will stay home from the PIR AX. I paid so will show early if you decide to come.

I may eventually throw in the towel, but not yet, this is more about understanding how this stuff works. Plus, I don't like that those guys and almost everyone else has a months long waiting list to do things like get alignments.

[PeteKz]

Something else that will make your car pull one way or the other is offset corner weights. Make sure the car is corner weighted evenly too. 911's are particularly sensitive to this, whereas other cars not so much.

Also roll the car forward 1/2 wheel turn and recheck to correct for a slightly bent wheel.

Like stownsen914 noted, those differences from front to rear of the rims seem too large. And why are you running 2+ degrees of negative camber at the rear? Should be 1 degree or less. Are you setting it up as a track car?

[nickelplated5s]

Pm

[kyngfish]

Originally Posted by PeteKz

Something else that will make your car pull one way or the other is offset corner weights. Make sure the car is corner weighted evenly too. 911's are particularly sensitive to this, whereas other cars not so much.

Also roll the car forward 1/2 wheel turn and recheck to correct for a slightly bent wheel.

Like stownsen914 noted, those differences from front to rear of the rims seem too large. And why are you running 2+ degrees of negative camber at the rear? Should be 1 degree or less. Are you setting it up as a track car?

I was going on this based on memory, but it's been a few years, so i haven't looked at it in a while, I'll reduce camber, and bring the overall toe narrower - but what I'm getting at is, why is the wheel going so hard to the right? based on the overall measurements, my toe is out of spec, but it's out of spec in different directions.

I guess I'll remeasure everything when my string kit arrives and I can set it up directly on the car.

[brianlay]

Have to agree with others, that's too much toe-in front and rear.

Factory spec for front is 15' total or 1.8mm (assuming 16 inch wheels)
Rear should be 10' per wheel or 1.2mm

You really run 0 toe front and rear and still be ok.

Caster should be as close to equal side-to-side as you can get it.

Those camber numbers are ok but the rears are a bit much.

Really should have the car corner balanced but equal ride heights side to side will get you pretty close.

I suspect you main issue is excessive toe-in.

[eastbay]

Your front cambers are backwards.

The more negative camber on the driver front will make it pull to the right.

Set your front cambers equal if your roads are mostly flat, or slightly more negative camber on the right to counter steer for more "crowny" roads.