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alignment: converting from degrees to inches??

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Old Nov 20, 2002 | 02:27 PM
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solo-x's Avatar
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From: MA
Default alignment: converting from degrees to inches??

er, how do you do it? or maybe some smarter person then me can convert .25 degrees into inches for me?

does -.5 degrees of toe seem like a lot or a little?

nate-who is really surprised at how close the numbers were left to right after doing a hack alignment in his backyard.
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Old Nov 20, 2002 | 05:15 PM
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Default Re: alignment: converting from degrees to inches?? (solo-x)

There's no definite answer for that cuz it depends on the diameter of the wheel and tire (if I understand it correctly). The bigger the diameter is, the toe readings in inches would be greater even tho the readings in degree are the same.

HTH.


[Modified by Wai, 8:22 PM 11/20/2002]
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Old Nov 20, 2002 | 05:42 PM
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Default Re: alignment: converting from degrees to inches?? (Wai)

yeah, i was really hoping for the trig formula. i think it's sin (angle) * radius of wheel/tire. if so, it works out to about 1/10" of toe out total. does that sound right?
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Old Nov 20, 2002 | 09:19 PM
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Default Re: alignment: converting from degrees to inches?? (solo-x)

i think it's sin (angle) * radius of wheel/tire.
Yup I think that's it.
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Old Nov 21, 2002 | 03:55 AM
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Default Re: alignment: converting from degrees to inches?? (Wai)

Having given this very little thuoght, I would probably use the *diameter* of the wheel rather than the radius. Toe is a measurement that compares the front of the wheel to the back of the wheel, not the front to the middle.

Here's a nice little chart I found.

http://www.smart-racing.com/pdf's/To...on%20chart.pdf

Scott
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Old Nov 21, 2002 | 06:43 AM
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Default Re: alignment: converting from degrees to inches?? (Wai)

Actually once you get the 1/10" and do a quick sketch on a piece of paper, you would find that the total toe would be 4/10" (0.4"). Assume x to be the distance from center of hub to center of hub:

x + (1/10 + 1/10)

--\------------/--
---\----------/---

x - (1/10 + 1/10)

*Total* toe would be [x + (1/10 + 1/10)] - [x - (1/10 + 1/10)] = 4/10


[Modified by Wai, 9:47 AM 11/21/2002]
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Old Nov 21, 2002 | 07:09 AM
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Default Re: alignment: converting from degrees to inches?? (solo-x)

Edit: Sorry, did not get what you were talking about at first.


[Modified by 6ghatch, 1:32 PM 11/21/2002]
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Old Nov 21, 2002 | 09:26 AM
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Default Re: alignment: converting from degrees to inches?? (celica73)

This should help:



To convert a known toe setting (call it Ta) and a known tire diameter
(call it Da), use this equation to convert to a different tire diameter
but using the same toe. For those who hate the math, just use the
graph. For those who want the exact number and not interpolate
from a graph use this equation:

(Ta/Da) = (Tb/Db)

Where Ta = known toe setting

Da = known tire diameter

If you want the same toe angle with different tire diameters call
those Tb and Db.

If you do the algebra, you end up with:

Tb = Ta * (Db/Da)

You can see that measuring toe accurately is not something that
you can take for granted.

Note: Taken from http://www.smartracing.net
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