[V8Vairs] Alignment/suspension setup

[craig nicol]

Jim wrote:
There are two core issues with the Corvair front suspension that are not
addressed by changing springs and adding a sway bar.  First is the fact that
it has completely screwed up Ackerman angle.  This is the line through the
steering arm pivot and the lower ball joint, which should cross somewhere
near the middle of the rear axle line.  Because the Corvair is front steer
(steering linkage in front of front axle line) and the steering arms angle
in, this line on a Corvair points outside the car body into infinity and
beyond.  This problem causes the outside wheel in a corner to turn much more
sharply than the inside wheel, causing the outside wheel to "plow". By
converting to a front disc set-up, which you should anyway with a V8, you
can gain the needed room to angle the steering arms outward and into the
wheel, providing proper Ackerman angle. My arm is about 3/8" from the disc
and my wheels are within 6 degrees of each other through the turning radius.
 
Craig replies:
While I agree that a common way to look at Ackerman angle is by drawing the
line you describe, I will disagree that it's a problem for front steer
suspension. Ackerman effect exists in both front and rear steer designs. In
my understanding, Ackerman is adjusted by moving the relay rod (or steering
rack) fore or aft in relationship to the tie rods. With this you can adjust
the Ackerman between positive, neutral, or negative. This is the problem
with quick steering arms (that screw up the Ackerman) because they move the
tie-rod ends back relative to the relay rod, causing too much Ackerman
effect.