The Bus

I just had my car aligned and ask for slight toe out [ 1/16" per side ]on front and slight toe in [ 1/16" per side ] on rear. Since the data on the alignment print out is in + or - degrees for toe ; which is toe out +or - degrees ???? Since my nature is not to trust people to do their job correctly I'm checking

Yes I had the camber adjusted also its easy to see the negative camber.
Thanks

BEZ06

Most all commercial alignment racks use the convention that a PLUS sign indicates toe IN; and a MINUS sign indicates toe OUT.

If anybody has the old Pfadt alignment sheet, they have a note at the top that says their negative (-) settings indicate toe-in, but that is opposite of most all machines/racks in alignment shops.

Bob

trackboss

Degrees is universal. Inches is not. Reason is because the same degree of toe will measure differently in inches/mm depending on where it is measured. People talk all the time about 1/16" toe out etc., but it is meaningless unless it is accompanied by where the measurement was taken. The only toe that can be duplicated without such additional information is zero. That all being said, most, if not all, the alignment information you read or hear about is not as helpful as one might think. Caster is much the same way.

NASCAR314

My alignment guy and his laser machine call "toe in" as positive and "toe out" as negative. [contrary to my thinking]

Camber, top of tire leaning in towards engine is negative [same as my thinking]

Me and him have gone round and round about this (toe) and he showed me on rack that he was correct on his machine (toe in is positive and toe out is negative)

everything in degrees is only accurate way to do it as mentioned above.

froggy47

Doesn't matter so long as you know what it means & it's what you wanted.



What type of driving and/or competition do you have in mind> That's useful info.

The Bus

HPDE 4 track days. I have a comp license but at 73 I am not racing fender to fender anymore. It's a C6 Z51 coupe. Based on the info you guys supplied the toe is backward. )(*&^%$#$%^&*()_)(*&^%$

TKOGTO

It may not be. Bob and Nascar both point out that (+) is generally accepted as toe in. However the Pfadt specs have (-) as toe in. As such, it depends on whom you are talking to.

Depending on the degree of toe, you might be able to tell. Look @ a tire carefully as it sits on a level ground. It might be apparent. Although with 73 yr old eyes you might want to get the grandson.

parsonsj

(not meaning to derail): Follow up question: sign aside, what is the angle value that corresponds to 1/16" or 1/8" toe? Is that the total angle, or the angle of one wheel?

I just ran into this as I had the local guy check my DIY alignment (yes, Froggy, some of us do look at your videos, lol).

The Bus

The print out indicates +0.17* left +0.18* right Fronts
-0.12* left -0.12* right rears

And as the responses indicate this to be wrong. Backwords. )(*&^&*(*&^&*((*&* Therefore I'm borrowing a set of toe setting plates/measuring tapes and setting the toe myself.
(*&^%$%^&*(*&^&*()(*&^&*(

Mark2009

I ran into this with a GM alignment guy. He kept insisting the graphic display on his machine was wrong on toe (the +/- deal), and to ignore it. I found this odd, and told him to simply keep toeing in one wheel and we would watch which way the numbers went on the machine.

The machine was right and he was wrong

So, whatever the numbers are, if you are there while the guy is doing it and there is any confusion, just tell them to keep cranking in more toe-in and see which way the numbers go on the machine... if they are negative and get more negative, then that's the way the machine interprets toe-in.

If they are positive and get more positive, then that's the way the machine interprets toe-in.

parsonsj

That's for 1/16", right? So 1/8" would about .35* per tire, I'd guess.

BEZ06

You can really only talk about the angle of toe as it relates to each individual wheel.

However, when measured as a distance (inches or millimeters), you can measure the toe of each individual wheel, or probably more commonly the "TOTAL" toe when you measure across both wheels.

If you're using the string method, you'll measure each wheel individually - the difference between the distance from the string to the rear of the wheel and from the string to the front of the wheel. If the rear distance is, say, 6 inches and the front distance is 6-1/8 inches, then you have 1/8" of toe-in for that wheel.

If you're using toe-plates or such (measuring across the car to get the distance between the rear of both wheels and the front of both wheels) then you will get TOTAL toe. That method is documented in David Farmer's DIY info here:

https://dl.dropboxusercontent.com/u/1634366/align.pdf


Scroll down to the section "Measuring Toe". You'll see his example of 68-1/4" between the rear of the tires and 67-3/4" between the fronts. The difference between those measurements is 1/2", which is the TOTAL toe - and the fronts are closer together than the rears, so it's toe-in.

With a total toe of 1/2", each individual wheel has a toe-in of 1/4".

Converting a distance measurement to an angle is simple trigonometry. In David's document, scroll back up to the first page, the "Measuring Camber" section, and you can see he tells you that for an 18" wheel, 1/8" is equivalent to about .375 degrees (I actually just did the trig and got .39789 degrees).

If you have measured TOTAL toe, divide by 2 to get the individual toe for each wheel when converting to angular measurement.

The farther apart between the points where you're measuring the front and rear distances, the smaller the angle for the same distance measurement. In his "Measuring Toe" section David is measuring where the tire meets the rim. As mentioned above, for an 18" wheel a 1/8" is about .4 degrees, for a 19" wheel 1/8" equals about .37 degrees, for a 20" wheel 1/8" is about .36 degrees, and if you're measuring such that your front and rear measuring points are 24" apart then 1/8" is about .3 degrees.

1/16" toe measurement of an individual wheel would be one half of the angles above.

Just my calculations, your math may vary!!

Bob

Bill Dearborn

There isn't any standard agreement on the sign value of toe. If you search on the internet you find it described both ways. Most of the time they use + for toe in but it is far from certain thing. Best thing to do is to always spell out what you want: TOE In or TOE Out.

As for converting from inches to degrees there is a pretty good chart on the Smart Strings web site. It provides curves showing how to do the conversion for each wheel.

http://www.smartracingproducts.com/s...ings_chart.pdf

The nice thing is it gives you the tool to determine what the angle is depending on the front-rear distance across the tire where you make the measurements.

http://www.smartracingproducts.com/s...able-cw-v3.pdf

Bill

froggy47

This is what I do with the strings, I would think a computerized alignment rack (assuming its calibrated correctly and assuming the operator is trained on it and assuming he/she is having a good day, it's not 10 min to closing, he/she didn't just get off a cell phone after breaking up with a partner, etc.) does it the same way.

Total toe means nothing unless each rim is measured (front and back of rim)to the centerline.

.

My Vette never sees an alignment rack. Everything you need to align your Vette is in your garage now, you don't really need the trick tools I have to do it, but they are nice tools.

Painrace

Buz, I am 70 and still doing some racing. Good to know I still have a few more events.

For road coursed you want 1/16" toe out in front and 1/16" toe in on each rear wheel. It is easy to measure what you have on level concrete with string.

Jim

The Bus

The reason I quit wheel to wheel racing is that my race car caught on fire in May during a race and destroyed the dash/firewall wiring completely. Don't have energy or desire to rebuild.