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I don't know anything about any other racing besides 1\4 mile racing, so im posting here. We, unlike all other rear wheel drive cars (almost) have rear caster bars to adjust caster negatively or positively.

For those of you who do not know what caster is, imagine your struts in a vertical position, this is known as 0 caster. if you were to keep the spindles in the same position, but move the top of the strut towards the front of the car, this is known as negative caster, if you were to move it towards the steering wheel, this is called positive caster. On front wheel drive cars, adjusting the front caster controls your handling and stability in the steering.

Now, i was wondering if any adjustment of caster would be beneficial in launching a car in a drag race.

just a random thought i had while under the motor of one of my parts cars while it was 12 degrees in my garage...brrrrr. where is spring?

comments, questions, and suggestions welcome.
tyler
 
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no thoughts? is there a better place to get answers?
tyler
 

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Caster in the front has a self-centering affect (as in, release the wheel and it spins back to the center position on it's own). I have never read (or remembered if I did) anything about the affect of caster in the rear.
 

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pontiac5oh said:
For those of you who do not know what caster is, imagine your struts in a vertical position, this is known as 0 caster. if you were to keep the spindles in the same position, but move the top of the strut towards the front of the car, this is known as negative caster, if you were to move it towards the steering wheel, this is called positive caster. On front wheel drive cars, adjusting the front caster controls your handling and stability in the steering.
tyler
where did you steal that one from;) moving it toward teh front of the car, and the steering rear is the same;)
 

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huh? ... what you say Manning? :)

Moving toward the "front of the car" or toward the "steering wheel."
Where did you get "steering rear" from?
 

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?!

I am soooo lost.


I was being serious. I didn't get what you meant in your first post. Maybe I am being dim today?
 

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Dorko SuperMod
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hahaha
i was commenting on how the statement generalized the situation in a fwd car, the caster on the front wheels would either go to the front, or to the steering wheel..

but on a rwd car it's to the front of the car or to the rear..


i just sucked at typing wheel and wrote rear..

sorry;)
 

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If you were to adjust the rear caster so that the rear wheel/tire was farther forward, you could get more rear weight bias. :) Would look funny not having the wheel centered in the wheel opening though. ;) Of course you could get custom camber/caster plates built for the rear strut tops to adjust rear caster and still keep your wheel/tire cetnered in the opening. Anyways, I just can't see rear caster making much difference in launching, especially since the amount that you could adjust it would be quite small.
 
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Discussion Starter #10
manning, that line was a tyler caruso special. i didnt "pull" it from how things work or anything like that :)

tyler
 

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Caster is adjusted by the strut bars for MKI and early MKII cars. The most important thing I do know is that you want it to be the same from side-to-side.
 

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Dr. Pepper said:
If you were to adjust the rear caster so that the rear wheel/tire was farther forward, you could get more rear weight bias. :) Would look funny not having the wheel centered in the wheel opening though. ;) Of course you could get custom camber/caster plates built for the rear strut tops to adjust rear caster and still keep your wheel/tire cetnered in the opening. Anyways, I just can't see rear caster making much difference in launching, especially since the amount that you could adjust it would be quite small.
MR2 altered wheelbase funny car?!
:thumbup
Wouldn't that change the angle of the trailing links (?) and cause the tires to get pushed into the ground a little bit more?

It would also work in reverse. You could extend the wheelbase slightly. If you added caster to the front, you might end up with an inch total. That might be noticeable.

Could changing the rear caster help minimize rear toe out on 91-92 cars?
 

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PDoane said:
Caster in the front has a self-centering affect (as in, release the wheel and it spins back to the center position on it's own).
Yup... like the caster wheels on a shopping cart:

 

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pontiac5oh said:
good Q!

tyler
Thanks!

If you think about the rear of the MR2 as a FWD suspension, then the links that control toe are just fixed steering links. So, if a (typical MacPherson strut)FWD suspension gains more camber when the wheels are turned if caster is increased...then the Mk2 rear would gain more camber IF the fixed links act like they were steering in the right way. Maybe the short 91-92 links could do that even more if they were spaced UP or DOWN??

Wouldn't changes in TOE decrease and camber gain increase when caster is changed by moving the wheels forward?
 
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