Questions for Alignment Experts

[KC2SHO]

I just had my 95 SHO aligned. The tech told me that just about every adjustment had to be changed. I expected as much since the car was in an accident before.

The results of the alignment are as follows:
(Red = out spec, Green = in spec)

Front left:
Camber -2.41°
Caster 2.30°
Toe 0.05°

Front right:
Camber -1.32°
Caster 4.04°
Toe 0.06°

Front:
Cross Camber -1.09°
Cross Caster -1.73°
Total Toe -0.11°

Left rear:
Camber -2.01°
Toe -0.06°

Right rear:
Camber -1.17°
Toe -0.02°

Rear:
Total Toe -0.09°
Thrust Angle -0.02°

So how bad are the out of spec numbers? Which ones should I be most concerned about correcting? What bad handling characteristics will I notice if I start pushing the car to the edge? How about tire wear? Since I run some nice soft BFG Traction T/A's I'd like the get the most out of them.

It's driving better than I remember before the accident but I only had it for 6 weeks before the b&$ch hit me. Should I be happy with these numbers and send it off to get the fit and finish done on the body work?

Any help would be greatly appreciated. Sorry for my lack of knowledge on alignment matters.

 

[Shoaz]

I'm not an alignment "expert", but I do my own alignments for track use with good success.

The balance in the front of both caster and camber are not so good. Lots of camber is usually good for handling, but when it's misbalanced it may behave a little strangely. Even worse is the misbalance in caster. The combination of the two may make it a little funny to drive sometimes.

Same thing on the rear, and if you have stock control arms I'd inspect them closely for damage. Usually the camber can't be that far off in the back unless something is bent or a bushing is aging. Check the left rear closely.

You may want to find a reputable alignment place and take it in for a second opinion. I suspect that either you're seeing the effects of old bushings, bent components, the accident has tweaked the chassis and it hasn't been properly straightened out, or the alignment shop isn't very good at what they're doing. Perhaps a combination of those.

On the other hand, if it's driving to your satisfaction and the tires don't start to wear funny, then there may not be a reason to bother with it. I wouldn't be trying any corners at the limit, but for many folks that's not a concern.

 

[rksc90]

thats off by a mile, is your car lowered? you're going to have serious tire wear and a pull

 

[KC2SHO]

Shoaz - Thanks for the information. I may take it to an alignment specialty shop. First I will inspect everything and replace the very few components that have not been replaced yet by me. The alignment tech told me that the Camber could not be adjusted on my car. Is this correct?

rksc90 - The car is not lowerd. There does seem to be a very slight pull to the right but I drive on some of the worst roads in South Jersey. The roads I frequent are all crowned. I will be keeping a close eye on the tread wear.

Thanks guys.

 

[Shoaz]

The alignment tech told me that the Camber could not be adjusted on my car. Is this correct?

No, that's not correct. It's very easy to adjust on the front once the welds have been broken, which is very likely already done on a car this age. The rear is more or less not adjustable if you have stock control arms, other than a little bit of toe adjustment, which is fine in the data you showed.

That being said, there is a limited range of adjustment in the front. One thing that can be done to help is to realign the subframe. The subframe can be shifted around a bit and it has an affect on the alignment. From the numbers you've posted if it is moved to the right, and the left side shifted back a bit (or the right side forward, wherever there's room), it will help allow the two sides to be balanced better.

It could be that the subframe had just shifted over time or when the car was repaired, or it could be that it just needs to be moved to compensate for chassis distortion due to the accident. In any case, if you take it to another shop ask if they can move the subframe around a bit to help the alignment.

 

[SHO SPD]

Holy crap.. your specs are not good at all. That is not even close to an alignment being done, I hope you didnt pay for that. WOW thats all I can say. Your cross specs are the most inportant to look at especially on caster, because thats what will cause your pull to either direction a-lot. Camber will also cause a big pull if the cross is off more than .5* for camber and caster. within .5* cross you should have too many problems. But you better take that back or get your money back. Even toe should be at .10* if I remember correctly. I will double check in a min. ok just checked my alignment spec book and toe should be at -0.2* both sides. specs are .05* and -.25* but it calls for -0.2* to be the best measurement.

 

[twr]

Wow, there is something very wrong. I just had my car aligned last Friday. My car sits pretty low, so I was suprised they got the fronts where I wanted it. The rear is easy on mine because of the adjustable control arms. As far as have negative toe on the front, I would disagree with the book and say a little positive toe is a good idea, mainly as the driveline is under load, it will tend to want to toe out a little.

If the subframe can be adjusted enough as described above, you should be okay, but that's way out. Looking more close at you numbers, you have -2.41° camber on the left and -1.32° on the right. Even the if the subframe is adjusted from side to side, you are going to wind up with -1.865° camber on both sides, for a car a stock ride height that's bad, the range is -1.1° to 0.1°

Here is how mine came out

Front left:
Camber -1.5°
Caster 5.1°
Toe 0.18°

Front right:
Camber -1.5°
Caster 5.3°
Toe 0.01°

Front:
Cross Camber 0.0°
Cross Caster -0.02°
Total Toe 0.19°

Left rear:
Camber -1.5°
Toe 0.11°

Right rear:
Camber -1.5°
Toe 0.17°

Rear:
Total Toe 0.28°
Thrust Angle -0.03°

 

[SHO SPD]

Actually on front wheel drive the wheels tend to toe in. Rear drive the toe goes out. so a negative would be best that way when its under load they will be at zero

 

[Shoaz]

Although the spec may say -1.1 or so max negative camber, it won't hurt to go beyond that. i.e., -1.8 camber won't hurt anything unless you have a wheel/tire combination that is especially sensitive to negative camber.

I've run at or greater than -2 degrees of negative camber for a long time with no adverse wear effects. Others have had wear issues with less. In any case, the addition negative camber (or postive caster, for that matter), beyond the spec range will just make it a bit sportier. If for some reason the camber or caster can't be balanced within the spec range, it's just more important that they be balanced at whatever you can get. If the camber is more negative than spec or the caster more positive, I wouldn't worry about it at all. If the tires wear funny, a less sensitive type of tire may be the best solution if the numbers can't be brought into spec.

 

[KC2SHO]

Thanks for all of the great replies. The more I drive the car the more I am noticing a slight pull to the right. It's not bad, especially considering the way it was before. This car was actually airborne for a split-second. Maybe only a few inches, but airborne none the less. It slammed into the ground and took up some turf.





I was forced to start driving it again when the transmission started acting up in my 93 last year. It's been struggle to get it back in shape ever since. Driving a car that needs work is never fun. I'll have to check the sub-frame alignment at some point. I should have done that and taken the car to the alignment specialist that I have always used in the first place. I went to a local Firestone to save me the trip, which will now only end up costing me more money. Oh well, a reality call was in order I suppose. I sometimes forget why I don't like anyone touching my cars but me. If I only had an alignment rack in my garage...

On the bright side I've been learning a lot about one of my least knowledgeable automotive subjects, alignments.

It’s time to find a winter beater and fix her up proper. I'll be happy when the SHO looks like the day I bought it.

Before:


After:

 

[Shoaz]

Wow. Glad to see it's coming back together!

Home aligments aren't that hard. The only special tools you need to align a SHO are a caster/camber tool (anywhere from $120 - $300, I've been using an economical one with very good results), and place to park it where the car will be level.

This is the caster/camber gauge that I use:

http://www.racerpartswholesale.com/polpos.htm

There are cheaper ones available, and more expensive ones as well. RPW also has a little one for about $40, but I have no idea whether it's a PITA to use or not.

Here's a pic of a really inexpensive conduit-and-string setup that works nicely on GenIIs for setting toe:



I put grease between two 12"x12" pieces of white board and put them under the tires. This stress relieves the joints so that you're really setting alignment and not just putting load on the tires.

So for about $180 you can have adequate tools to do your own alignment. I've been doing mine this way for a few years and have gotten better results than I ever got from alignment shops, IMHO.

Keeping reading up on it. The SHO is pretty easy to adjust in the front. The stock rear just has a couple of weird eccentric bushing in the back to set toe, but if you have GM/BMR/adjustable arms in the back you can set camber and toe easily.

BTW, related thread with more info here: http://www.shoforum.com/showthread.php?t=34522

And personally I'd not trust a Firestone shop for a good alignment unless I knew the folks well. Other sources beckon.

 

[rksc90]

yea, your subframe might of shifted over, if drilling out the upper strut mount plates and re-aligning the frame doesnt work, i would at least have both sides the same(in or out of spec). Looks like the frame got pushed back on the drivers side and shifted to the right if the alignment was ok before