Hey guys, I finally got the suspension redone on the Comet... and not knowing a good alignment shop around me, I took the car down to Firestone.. Needless to say, the alignment is "good" the grocery getter everyday car... but I think it leaves a lot to be desired for the track.... Specially the Caster being negative... the car wondered before going down the track before.. now it stay straight, but once it gets into the 90+ mph it feels like there is a small vibration... I wonder if the caster being that negative is giving the "shopping cart" effect??
I'd take it back and have them set it at least +2.0°. The negative caster is defiantly your "shopping cart" effect. The more positive caster you have the more stable at speed it will be, down side is it'll be harder to steer. I'd also have them set the camber at 0°.
For drag racing you want the top of the tire toed in 2 deg.This makes the car want to go straight & easier to control at high speeds as MaverickDan said.
Whats used to control caster... shimming the upper arm or the strut rods?.. I thought the later suspension 75 or so + the upper wasn't adjustable like the early say 60s stuff?
Another thing I forgot to mention also from the lack of caster is the "return-ability" of the steering back to center after making a turn... I will swing by the firestone on my way home..
If adjusting the strut rods won't get enough positive caster you can pull the upper control arm(s), remove bolts and rotate the shaft toward the front of car(be opposite direction for each side)... This will move the arm rearward, giving more adjustment from strut rods... Yes it's a PITA, but I've heard of some people pulling the lower arms so far forward while trying to increase positive caster, that they were dragging on the mount...
