What's happened to my alignment?

[Kirk911SC]

I had my car ('87 930) in for an alignment check today due to a slight drift to the right, and to help eliminate possible causes of a braking problem, see:

http://forums.rennlist.com/rennforums/showthread.php?t=354147

The readout was as follows:

L/R -Front

Camber: -1.8/-0.6
Cross Camber: -1.1
Caster: 5.5/5.9
Cross Caster: -0.4
Toe: 1/16" / 1/16"
Total Toe: 1/8"

L/R - Rear

Camber: -0.6/-0.7
Toe: 1/8" / 3/32"
Total Toe: 7/32"
Thrust Angle: 0.03

The tech said that he would have to spend a lot of time removing the factory "tar" on the shock towers, and that he "hadn't done one of these cars in a while".

Needless to say I didn't have him make any adjustments, but I have a baseline now.

Car has been lowered, has a front strut bar, newish tires, has never been in an accident as far as the records indicate, and not had an alignment since I've owned the car - about a year.

What's happened here? What should I get the settings adjusted to? No track time, but I would like a sharp handling street setting.

Thanks.

Kirk

[Joe Bob]

Lowering will require an alignment as it changes the "at rest" specs. Returning it to the last known ride height will most likely correct the pull.

[Kirk911SC]

Car was lowered by previous owner. Nothing alignment wise has been touched in the past year.

I believe it is set to "Euro" ride height.

[aj88cab]

Lowering would definitely affect the camber, but I would hope it was aligned and CB'd when it was lowered. Did they check the corner balance when it was in for the alignment check? What strut brace is installed?

It could also be that the front camber may have been affected when the strut brace was installed. Most braces attach to the camber plate bolts. Or possibly the camber plate bolts were not tightened properly and the plate slipped over time. This assumes that the strut is not bent or damaged.

Also, are you sure it is the alignment causing the pull. Have you checked for a sticking right side caliper.

Update>>OK, if I had read your Rennlist post first I would known the possible brake issue has been covered!

Good Luck
Andrew

[Kirk911SC]

The tire shop I took the car to didn't even know what a corner balance was! The strut brace is a JM, bought new from Pelican. Installed by yours truly last summer. It attached to two camber plate bolts. I suppose it could have moved?

I do have a corner balance worksheet from several years ago in the records, but no alignment data.

What settings should I aim for? I already have another guy in mind for the work.......he was working on a 930 when I called him in fact.

[aj88cab]

I also have a JM brace. If you noticed when you installed it, the end brackets are flat and the surface they mount to is curved. So you have to add washers to tighten the bolts properly. JM is revising that detail to have a curved bracket and will replace the flat ones when they go into production.

When you installed the brace did you remove all the "tar" on the strut tower? If not, you really can't get a solid stable mount and it would be easy for the camber to slip.

I'm going from memory here but my camber settings were for a 70/30-track/street usage. Front - 1.25L/1.25R Rear 1.75L/1.75R
Those settings will result in slightly more wear on the inside edge of the street tires. I don't recall my toe/caster settings. Hopefully others can give better advice for street only settings.

[KFC911]

FWIW, I'd remove the 'tar' myself before I'd let an alignment shop chip it away with a screwdriver or worse .

[Gearbox]

Outside of the factory spec suspension set up (which any good alignment guy will know, undercoating or no undercoating) the suspension should be set up to the way you drive. The normal Goodyear or STS will have no clue about corner weighting since that is mostly used by race guys or few vigorious street drivers. The only thing that looks out of range is the camber, and yes, by installing the strut, it could have pushed or pulled the shock towers through driving or improper installation. I suggest getting the camber squared away and by all means chck to see if the caliper is binding as aj88cab says. Just raise the front tires off the ground, hit and realease the brakes, and see if you can turn the wheel by hand. Both wheels should have the same resistance. I would also check tire pressures. Front toe is the usual primary suspect for pulling followed to a lesser degree by camber. Corner weighting, unless way way off, should only effect pulling left or right under braking and how the car handles around left and right turns. Since the toe is even side to side, I'm thinking camber. Since the car is lowered, suspension geometry will be changed from factory recommendation. Best way to figure camber out is to get both sides set evenly, go for a spirited drive making the same amount of left and right turns, and get pyrometer readings from the front tires, 1" from the outside, middle, and 1" from the inside of the tread. Your temperatures should read highest on the inside, dropping in temp to the middle, and dropping by roughly the same number of degrees more to the outside. You are looking for a even declining transition accross the tire. Say a 20 degree drop between readings. If the outside is too hot, you need more camber, if the inside is too hot, you need less, if the middle is too hot, you have too much air pressure. Good luck Allan

[aj88cab]

Originally posted by KC911
FWIW, I'd remove the 'tar' myself before I'd let an alignment shop chip it away with a screwdriver or worse .

A hot air gun or blow-dryer and a screwdriver (the putty knife was too flexible) did the trick for me. Take your time, heat the tar until it is soft and protect the fender edge incase the screwdriver slips!

Good luck
Andrew

[Kirk911SC]

The heat gun is a good idea. I bet the strut bar install has caused the problem......probably has shifted.

[KTL]

There's a slight possibility you could have a bent spindle. But give the fact that the only spec that appears out of line is camber, i'd not think a spindle could bend only affecting camber. Nonetheless it's worth mentioning for others who read this, having similar problems with their cars.

Keep in mind also that the alignment machinery could not be spot-on. I had my car aligned years ago and I was told they set it best they could and it appears my car had a "radial pull" due to tire issues (which incidentally were brand new Kumho MX tires). They didn't want to put more cross camber in it and said it is what it is. Well since then with many different wheel-tire combos the pull still exists. A friend with also an 87 Carrera had his car aligned there (we know the guy and friend actually used to be a wrench for him) and wouldn't you know it, Stefan's car came home with a pull to the right too...........

I concur on the heat gun suggestion for the tower tar. I have seen good results with the heat gun. Follow it up by using a solvent to remove all the black residue. 3M General Purpose Adhesive Remover works great for this. Just use something paint friendly!

[Gearbox]

Originally posted by KTL
Keep in mind also that the alignment machinery could not be spot-on. I had my car aligned years ago and I was told they set it best they could and it appears my car had a "radial pull" due to tire issues (which incidentally were brand new Kumho MX tires). They didn't want to put more cross camber in it and said it is what it is. Well since then with many different wheel-tire combos the pull still exists. A friend with also an 87 Carrera had his car aligned there (we know the guy and friend actually used to be a wrench for him) and wouldn't you know it, Stefan's car came home with a pull to the right too...........

I beg to differ with the first statement, alingment equipment is spot on. What you have is a bunch of grease monkeys that have no clue about suspension geometery and only move things around in hopes of getting close to the specs recommended by the machine. Coupled with most of them only getting paid for each alignment they do, the "good enough" syndrome is common. The manufacturers of the machine understand this, and while the machine will give you "spot on" measurements, it is programed with a "Range" so the tech can print off a sheet saying the car is aligned. The story they told you is just BS, blame it on something else that they have no responsibilities for. Much like getting the "we're waiting for the parts" routine as your car sits at the shop for another week or two.

Suspension set up is not rocket science, but it is a science. Every adjustment will have consequences and will effect something else. So this means getting everything correctly set will take time and an understanding of what will effect what. And yes, there will be compromises due to chassis constraints, but those could be fixed too. A full alignment from scratch on my race cars could take me 6-8 hours, and sometimes a couple of days to get it right. Needless to say, subsequent alignments are much quicker, but could also take a couple of hours. With the quality of commercial alignment available these days, you'll be better off getting a Smart Camber Gauge and some strings and do it yourself. As I said, it's not rocket science

[surflvr911sc]

Originally posted by KTL
There's a slight possibility you could have a bent spindle. But give the fact that the only spec that appears out of line is camber, i'd not think a spindle could bend only affecting camber. Nonetheless it's worth mentioning for others who read this, having similar problems with their cars.

Had this happen to mine. All specs fine but couldn't get the camber on one side dialed in. Way too much neg, ended up being a bent spindle.

In retro, I wish I had kept it and found another bent one; I wouldn't have to work so hard to get more neg now.

[rallyracer]

Most likely you have a pull from your front camber settings. That's a big difference side to side and with over a degree less on the right, you'll pull right, especially with the crown in the road. The caster and toe are fine. You can check for radial pulls from tires by just swapping sides. If it's a radial pull, yours will go straight or slightly pull left. Fix the camber first.
David

[KTL]

Gear,

I hear what you're saying and agree. In my case the alignment rack was not your run of the mill rack, but a proprietary setup the shop was developing- called AlignMax. For someone to develop their own alignment rack system, they must have a good understanding of the science. In this case, I think something was amiss with their system since mine and multiple others' cars came out of the garage with the same pull to the right.

[Porsche_monkey]

Have you considered taking it to Ernie at Mantis?

[911nut]

Gee, how did people align cars before computers and digital readouts were invented?
Kirk, alignment can be a DYI job if you are so inclined. Search the archives here and you will find a lot of smart guys have developed good home alignment solutions.
As for corner weighting, it's a good thing to do if you have the scales but not really necessary for a street car. I've just put my weight in the drivers seat and my preferred amount of gas in the tank (1/2) made the ride heights as equal to each other side to side as I could. Two other Pelicans have driven my set-up and have complemented it so I think I'm on the right track.

[Porsche_monkey]

Yes, he's right, you can do a pretty good alignment with a Lufkin and a Sears inclinometer. And time.

[ljowdy]

Two weeks ago, I had my 1973 aligned by a real pro in Riverside CA. First thing he asked was how I drove the car and how I wanted it set up. It's not a race car and I wanted it set up for spirited street driving.

Here are the final spec's. in degree's
total toe in .28 degree's .14 right and .14 left
left front camber -1.4 degrees right front camber -1.3 degree's
left front caster 5.0 degree's right front caster 5.3 degree's
steer ahead 0.0 degree's

left rear camber 1.0 degree's right rear camber 1.0 degree's
left rear toe in .14 degree's right rear toe in .135 degree's
total rear toe in .275

thrust angle .06 degree's

I handles great, travels straight down the road and is very responsive

I total cost to have all 4 tires balanced and all 4 wheels aligned was $155.00
I hope this helps

[rallyracer]

Originally posted by KTL
Gear,

I hear what you're saying and agree. In my case the alignment rack was not your run of the mill rack, but a proprietary setup the shop was developing- called AlignMax. For someone to develop their own alignment rack system, they must have a good understanding of the science. In this case, I think something was amiss with their system since mine and multiple others' cars came out of the garage with the same pull to the right.

so, you're saying we shouldn't be commenting on the specs you provided?