bhensarl

I was just looking at the printout I received after having my car aligned after my accident and I had a few questions for the alignment gurus out there. Camber, caster and toe I understand, but what are SAI, Included Angle, Thrust Angle and Turning Angle Diff.? Also, I assume Cross Camber/caster/SAI/Turn diff would be the difference between the settings on the right and left. Correct? Thanks.
Brian

bhensarl

Just found this website that explains the above,
http://www.aligncraft.com/terms/terms.html
now another question:
Everything is within specs except the caster which is 4.9 left and 4.8 right (the specified range for both is 3.9 degrees to 4.7 degrees). That's not good but here's what's really strange, the SAI (Steering Axis Inclination) is 6.3 degrees left and 0.5 degrees right. Obviously the included angles are very different also, because of this. The website says to check for vehicle damage if there's more than a 1.5 degree difference from side to side. Obviously my vehicle was damaged when it was rear ended. Is this something that the body shop should have fixed, or is it understandable due to the accident?
Brian

springer3

Brian:

Good questions, and you need to talk to a really good alignment tech. I know one in Atlanta you can talk to if you can't find someone local you trust.

Frame damage can be straightened on a special frame. I am not an expert in this area, but it is my understanding that a proper collision repair includes alignment to the factory specifications. Otherwise, you live with handling problems, tire wear, and almost no resale value (any competent PPI includes shooting the alignment).

Good luck

bhensarl

I did indeed, and it's already coming in handy as my A/C is mysteriously out of charge. I'm taking it in on Friday to get that diagnosed.
I don't have any info from before the crash.
The printouts I have tell me the numbers before the alignment shop got their hands on the car, and the numbers after. I'm going to give Springer3's guy a call (Thanks Springer!)and see what he has to say about the SAI, among other things.
Brian

springer3

Brian - you have a PM. I spoke to Jeff Mills at Gran Tourismo, and he says if you can keep between the ditches when driving, your SAI numbers are bogus. A repairable rear hit should not cause front alignment problems in any case. If you are ever in Atlanta, Jeff says he will dial you in properly, but if the car drives well, you are probably fine.

Hope this helps.

Edit: Most SAI problems are related to a bent front spindle, where the camber or toe-in are adjusted to compensate for the bent spindle. There is no credible way to bend a front spindle during a repairable rear collision. The theory that you have a bad read is looking pretty good, and you are probably fine.