I have gotten my cars closer to the specs I want than a shop can. When I started doing my own alignments I would take the car to a shop to verify and I was always dead nuts on. I have had friends come back from shops saying they could only get it close, and then I get it the rest of the way. Like the comment that has been made, even though the equipment is great it is only as good as the operator. At $150+ per alignment I trust myself way more than anyone else. I can also do things like account for driver weight and fuel load in my alignments.

 

I made my own toe plates, bought a $30 laser level, smooth tile and grease for slip plates, and use tape measures and math to do my alignments. About $45 and 1/2 hour invested in my "GOOD QUALITY" tools.

 

Do you allow for the laser level mounting error. I have 4 levels not one of them are 100%. error rate ~ 10mm over a 5760mm distance.

If so how do you account for this ?

 

I gave up on shops doing my alignment after a couple shops screwed it up, including a GM dealership.

I use a camber/caster gauge, toe measuring plates with 2 tape measures, 8 steel plates ground smooth to put under the wheels so they move easy, and some fine string mounted to some uprights (I've used jack stands before). Here's basically how I do mine.

1 - Put the car on the steel plates. Two per wheel with oil between them.
2 - Get the front toe-in close on the front (only after major mods)
3 - Set the front caster
4 - Set the front camber
5 - Set the front toe-in, centering the steering the best I can
6 - Set the rear toe-in. Here's where the string comes in. After I have the toe-in where I want it on the rear using the plates & tape measures, I place string along both sides the car. The string needs to be at a constant distance from the center of the car. Measure from the string to the front and back of the rear & front tires. Use these measurements to make sure the rear is tracking with the front. This is the most time consuming step, especially the first time. If you get this off, you can tell it when you drive. Even 1/32" can be noticeable, IMO.
7 - Set the rear camber
8 - Take if for a test drive
9 - Recheck all dimensions and adjust as necessary

Hopes this helps. Usually takes me 2-4 hours start to finish depending on what I am changing on the alignment, and if I have done any major suspension work.

Plus if I want to try changing my toe a little, or camber, etc. I have the equipment and knowledge to make an adjustment without spending another $150 each time. Granted I wouldn't say I'm the typical Corvette driver and many don't make these types of adjustments on a regular basis. But I think suspension tuning is interesting and a bit addictive.

 

What do you mean by mounting error? I only use the laser level to measure the thrust angle. I place it on the hub of the rear wheel and it projects a vertical line on a horizontal scale (or square) placed on the front hub. For thrust angle you are just looking to make sure the wheels are the same side to side so it is a relative measurement not exact. I use the tape measures for toe once I know the wheels are the same relative to the front.

 

Have you tried using a laser level on the rear tires to measure thrust? I got away from strings years ago because a level with a magnetic base is much much faster.

 

Jason, excellent post.

 

I thought you might be using the lasers to measure toe as well. For rear thurst it doesn't matter since it is a relative measurement.

I use lasers to measure toe so for me it matters to get the correct measurements.