rack n pinion front steer ackerman issues...explain...
When you read about the scary ackerman concerns it is referring to a rear steer car made
into a front steer by flipping the arms side to side to make them point forward for a front
steer (front mounted rack) setup.
The Wikipedia article RRR posted explains this well. Notice the different front wheel angles
when turning with a properly set up rear steer (stock) vehicle.
Illustration courtesy of Wikipedia
When you flip those arms side-to-side it has the opposite effect, making the outside wheel
turn much more sharply than the inside one. This is very difficult to drive and when backing
up while turning it tries to peel the tires right off of the rims.
The correct geometry can be achieved by designing a steering arm that has the outer tie-rod
end fall on an imaginary line drawn through the lower ball joint to the center of the differential
as illustrated, again excellently, in the Wikipedia article.
Notice that if the arms were pointed forward for a front steer that they would be practically
into the tires. The very best illustration I could find to exaggerate the point is to look at the
photos below of the properly configured steering arms on a front steer Bugeye Sprite.
Illustration courtesy of Wikipedia
When you read about the scary ackerman concerns it is referring to a rear steer car made
into a front steer by flipping the arms side to side to make them point forward for a front
steer (front mounted rack) setup.
The Wikipedia article RRR posted explains this well. Notice the different front wheel angles
when turning with a properly set up rear steer (stock) vehicle.
Illustration courtesy of Wikipedia
When you flip those arms side-to-side it has the opposite effect, making the outside wheel
turn much more sharply than the inside one. This is very difficult to drive and when backing
up while turning it tries to peel the tires right off of the rims.
The correct geometry can be achieved by designing a steering arm that has the outer tie-rod
end fall on an imaginary line drawn through the lower ball joint to the center of the differential
as illustrated, again excellently, in the Wikipedia article.
Notice that if the arms were pointed forward for a front steer that they would be practically
into the tires. The very best illustration I could find to exaggerate the point is to look at the
photos below of the properly configured steering arms on a front steer Bugeye Sprite.
Illustration courtesy of Wikipedia
