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Author Topic: Effect of lowering on overall alignment?
Qik Nip Verified Driver Made Donation to Website Series Champ
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I realize that dropping the ride height increases negative camber, but as I think about it, won't it also effect caster and toe?

I suspect that it causes an addition to toe out, but I couldn't mentally envision the caster effect at all.

Soooo... the question is, does it (either or both) and if so, about how much caster and toe per inch of drop?

Rick
P.S. My reason for asking is whether I can drop my wife's '93 STS2 Miata and an inch without resetting the entire alignment.

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Fortune Cookie Racing SM 60
Directions for use: Race, Rumple, Repair ... Repeat!

Gibscreen Verified Driver Series Champ
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It will definitely give you toe out on the front. Not sure about caster. And I don't believe it will have an effect on rear toe. Setting toe on the front is simple with toe plates--the only problem that might arise is the steering wheel could end up a bit off center since toe plates only measure total toe.

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Rob Gibson
RJ Racing
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Qik Nip Verified Driver Made Donation to Website Series Champ
Loose Member '09 & '10 Great Lakes Regional Points Champion

Region: Cincinnati Great Lakes
Car #: 60
Year : 1990
Posts: 1487
Status: Offline
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Rob:
Thanks. I'll measure it and see what the total toe amounts to. In a AX car, front toe out assists turn, so a bit more won't hurt and might help.
Rick

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Fortune Cookie Racing SM 60
Directions for use: Race, Rumple, Repair ... Repeat!

tony senese Verified Driver
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Rick,
I check the toe every time I adjust the front ride height with toe plates, I can't really measure a difference for small adjustments (one turn or so). If you drop the car an inch you will see a pretty big change and I agree with your idea that a little toe OUT helps turn in, but it also increases rolling resistance and slows you down in a straight line. I try to start with as little toe as I can get, which is what JD recommends for his basic setup.

I don't measure caster so I can't say what happens there.

Tony

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Tony Senese
SM#99
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Slow Ride
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Caster should not be affected at all if both ends are lowered the same amount. Rear toe should not be affected either or every bump on the road would change the toe momentarily. Camber will be changed, by what amount I don't know.

Tony, I think you meant that toe out helps turn in. Straight line speed is not as essential in autoX.

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No matter where you go, there you are.

tony senese Verified Driver
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quote:
Originally posted by Slow Ride:

Tony, I think you meant that toe out helps turn in. Straight line speed is not as essential in autoX.

Exactly, not sure how I typed it wrong... [Eek!]

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Tony Senese
SM#99
2008 NASA-NE SM Champion
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Matt Johnson Verified Driver
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quote:
Originally posted by Slow Ride:
Caster should not be affected at all if both ends are lowered the same amount. Rear toe should not be affected either or every bump on the road would change the toe momentarily. Camber will be changed, by what amount I don't know.

Tony, I think you meant that toe out helps turn in. Straight line speed is not as essential in autoX.

Rear toe will also change with ride height/bumps, pretty much every production car changes rear toe with ride height and/or body roll angle (see, that last statment was thought out; even cars with solid axles have roll steer [scratchchin] ).

Also caster may change too, if I am thinking through the geometry correctly (may not be, it has been a long day) there will be kinematic caster change with ride height if there is anti-lift or anti-squat built into the geometry.

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Matt Johnson
1990 SM #73 - yet another red miata.

   

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