C3 Alignment spec questions

[JPhil]

1) For toe-in specs, how do inch fractions compare to degrees? All my spec sheets call out fractions of inch for toe adjustment, but the alignment machine uses degrees.

B) How does rear toe work in conjunction with front? My VBP paper calls out 1/32" front toe-in & 1/8" rear toe-in, but the alignment machine 'spec range' call out says .13*-.38* front & .06*-.19* rear.


I currently have .12* front toe-in (.04* left & .08* right) and .05* left rear & .11* right rear.

I want to even up the rear, but am not sure which way to go--more toe-in on the left or less on the right? (I'm thinking more on the left.) (& I am roughly guessing a 1/16" shim change on one or the other: this will be a home garage job, I'll put it on the rack later to verify & adjust camber accordingly.)

I'm going to increase the toe-in on the front a little as it is a bit too sensitive on the street for me. As things stand now, I don't think I'll ever be taking this car to a track, so I want it to be stable on the street. Quick cornering response is no longer much of a concern. I'm more concerned with it staying true in the lane while I'm looking over my shoulder at the traffic on the highway....

I have several books on chassis performance I'm looking at, but I thought this would be a good subject here.

John

 

[redvetracr]

1) For toe-in specs, how do inch fractions compare to degrees? All my spec sheets call out fractions of inch for toe adjustment, but the alignment machine uses degrees.

B) How does rear toe work in conjunction with front? My VBP paper calls out 1/32" front toe-in & 1/8" rear toe-in, but the alignment machine 'spec range' call out says .13*-.38* front & .06*-.19* rear.


I currently have .12* front toe-in (.04* left & .08* right) and .05* left rear & .11* right rear.

I want to even up the rear, but am not sure which way to go--more toe-in on the left or less on the right? (I'm thinking more on the left.) (& I am roughly guessing a 1/16" shim change on one or the other: this will be a home garage job, I'll put it on the rack later to verify & adjust camber accordingly.)

I'm going to increase the toe-in on the front a little as it is a bit too sensitive on the street for me. As things stand now, I don't think I'll ever be taking this car to a track, so I want it to be stable on the street. Quick cornering response is no longer much of a concern. I'm more concerned with it staying true in the lane while I'm looking over my shoulder at the traffic on the highway....

I have several books on chassis performance I'm looking at, but I thought this would be a good subject here.

John

I believe 0.25* = 1/8"

 

[big2bird]

John,
I have found zero front toe to be too darty, and 1/8"(overall) is fine for normal driving. Same for rear.

 

[mrvette]

John,
I have found zero front toe to be too darty, and 1/8"(overall) is fine for normal driving. Same for rear.

I agree with Bird.....John, if you need them, I have alignment tables in the files somewhere, off a site that MAY be still active, if not, I can scan/send them to you...it converts degrees into inches depending on rim size.....

when doing my own alignment some years ago, right here in the garage, the floor was set/aligned and some formica pads on plywood with a slick greases beer carton for the tires to set on, turn the wheels really easy on them from the tire even.....to do the caster, obviously the rear needs be level too and with the front....as well as side to side....pretty significant slope to my garage, so 2" on right rear, 2.5" on left rear, and 1/4 inch to left front, to zero it out with the high tire, the right front....I think you get the concept....I used some 1.5" square stock steel and a carpenter's level ....to measure the rims, you can NOT use a level across the tires...you have to cut two shims to drill two long screws through them and into the sides of your level, just to catch the mounting ridge on the flat.....

you first alignment will take all day, I could probably start from scratch and do one in 1/2 a day NOW....learning curve....

I hate to say this, but I get a better alignment here in the garage than I can find in any shop here locally.....which sux...but being retarred, I don't have all the money to toss after crappy work....

:1st:

 

[BBShark]

If you have a calculator with trig functions on it, you convert like this. Say you have a wheel size of 15 inch diameter and you want to toe (angle) the wheel .25 degree:

Enter degrees- .25
Press the "tan" button
Multiply that number by 15.

In the example above you will end up with

.25tan x 15 = .065