just got an s2k, (stock wheels and tires.... some threads seem to think diameter of tire and wheel are factor {trig formula}) and i'm getting an alignment. i've searched for a while and can't seem to find the same answer twice.

what is 1/8" toe out in degrees?
i tried the s2000 section and i'm getting no help as of yet....maybe it's on the way.

TIA

 

I think total is .16

 

the equation you would use is:

calculator input would use sin^-1[(1/8)/(d/2)]=angle

where d/2 is the wheel diameter in inches, divided by 2.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bad-monkey &raquo;</TD></TR><TR><TD CLASS="quote">the equation you would use is:

calculator input would use sin^-1[(1/8)/(d/2)]=angle

where d/2 is the wheel diameter in inches, divided by 2.

</TD></TR></TABLE>

so it would be sin^-1[(.125)/16"/2)] ????

will this give me total or each side?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 95dc2 &raquo;</TD></TR><TR><TD CLASS="quote">so it would be sin^-1[(.125)/16"/2)] ????

will this give me total or each side?</TD></TR></TABLE>

Unless I'm mistaken, by "wheel diameter" he meant tire diameter. The size of the wheel (rim) itself is meaningless, its the total size of the tire that matters.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 95dc2 &raquo;</TD></TR><TR><TD CLASS="quote">so it would be sin^-1[(.125)/16"/2)] ????

will this give me total or each side?</TD></TR></TABLE>

it'll give you each side, and yes, you need to use tire diameter.

which should be something like 24.3" IIRC, (check your tire specs to be sure)

total toe out should be the sum of both sides.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bad-monkey &raquo;</TD></TR><TR><TD CLASS="quote">

it'll give you each side, and yes, you need to use tire diameter.

which should be something like 24.3" IIRC, (check your tire specs to be sure)

total toe out should be the sum of both sides.</TD></TR></TABLE>

since it will give me "each side" should i take my total desired toe of 1/8" and divide it by two to give me 1/16 each side, thus making it
sin^-1[.0625/(24.625/2)] = -0.0043

sin^-1[.125/24.625/2)] = -0.0085

which one do i go with for a total of 1/8" toe out???
TIA all trig majors


Modified by 95dc2 at 1:55 PM 3/6/2006

 

.085...

Even though with my math, i got that 1/8" of total toe will give you 1.74 degrees total toe. Either ways, you have your **** in degrees now.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Slideways2000 &raquo;</TD></TR><TR><TD CLASS="quote">.085...

Even though with my math, i got that 1/8" of total toe will give you 1.74 degrees total toe. Either ways, you have your **** in degrees now.</TD></TR></TABLE>

how'd i screw up and get an extra decimal place, ending up .0085 end stead of .085?

 

I don't know either, but thats the answer I have. My answer came out in decimals of a degree, which probably has to be changed to minutes on the machine.

 

hmm even weirder, my calc spits out 0.58 degrees if using 1/8" per wheel.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bad-monkey &raquo;</TD></TR><TR><TD CLASS="quote">hmm even weirder, my calc spits out 0.58 degrees if using 1/8" per wheel.


</TD></TR></TABLE>

i was using google's calculator. i lost my graphing calc somewhere along the way.

 

I think anyone needing toe in inches to degree conversions could use these charts

for toe given at tire diameter (most common)
http://www.smartracingproducts...s.pdf

for toe at wheel diameter (easier to set up for racing)
http://www.smartracingproducts...n.pdf

 

One very important thing to note about those Smart Racing Products charts are that the toe measurements they're using are <u>per side</u>, NOT total.

Here's a little graphic to help you visualize what you're trying to do.



The important things to keep in mind about this graphic are:

1. A is the angle per side, which is what the OP asked for.

2. T is the total toe. If you're using toe plates, you're measuring the total toe. If you're using strings, then you're measuring the toe per side, which is half of the total toe, so replace (T/2) with t (the toe per side).

3. Dt is the distance between the measurements. If you measure at the wheel, then it's the diameter of the wheel; if you measure at the tread, then it's the diameter of the tire; if you use toe plates, then it's the width of the toe plates.

4. arcsin means inverse sine.

As an example, I use toe plates that are 24 inches wide. My total toe is 1/8 inch. Plug these measurements into the formula and you get:

A = arcsin((0.125 / 2) / 24) = 0.15 degrees.

Take a look at the first Smart Racing Products chart. Find the line for 1/16 (the toe per side), and follow it over to the 24" vertical line. Then trace horizontally to the left and you see that you're halfway between 0.1 and 0.2 degrees. Thus 0.15 degrees.