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Discussion Starter #1
Took the car on a long drive yesterday, stears and rides great. It felt a little drifty or really easy to stear between 60 and 90 MPH. I have the caster set at 0 because it makes the parking lot manuvering much easier for me and SWMBO. Would adding caster improve the high speed feel of the stearing?
 

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Positive caster helps high speed straight line tracking but other things can make it feel loose. Camber is one. If the camber is set for low speed then when your car lifts some up around 90 the camber can be off. This can also pull your toe in off. There is also a sweet spot right in the middle of the idler arm on manual steering. If you don't have this lined up with your steering wheel centered before setting the alignment then the steering will always feel like you are having to put effort in one way or the other to keep it going straight. Worn ball joints will run ok at low speed but will make the car drift around at high speed. Flexing front rails as in not running an export brace, montecarlo bar and enging cross member will also make the car twitch around. In other words, every thing under the front end has to be right for it to track good and then adding caster will help improve high speed straight line stability.
 

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Brad - If you'd like just a bit more caster - try the Shelby A-arm drop. Moving the upper arm mounts back 1/8 inch will make the car more stable and the wheel return to center as you exit turns. If you are planning a suspension rebuild in the future, it would be a cheap and easy modification.

As the others have noted, though, more than 1 degree positive caster can be a problem for manual steering cars.
 

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Discussion Starter #5
All the suspension and stearing is new so no problems in that area. I did not lower the arms when I rebuilt everything because of timimg issues at my friends auto shop.

I thought when you lower the arms the caster should be set at +2 degress which would make the parking lot a real bear. I only drove the car at +1 degress with my old tires and the stesaring was difficult. I don't know what +1 degress would feel like with the new tires (205/70/14). I also went up one size in the back (215/70/14) with the new tires to get a little more rake to the car.

I am going on a road course in a couple weeks and am mainly trying to decide if it is worth another trip to the alignment shop ($60) to add a little caster back into the stearing, maybe to +1/2 degress?
 
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