Steering

Steering is critical to good handling and I am just now learning about the effects of toe, camber, Ackerman, etc and how to change these things. There is still lots to learn but I have to start somewhere.

The front suspension I am using is from a 1967 Jaguar XJ6 and as you can see in this picture of the drivers side suspension, the steering rack attaches to an arm that is behind the assembly.

Here is another view of the arm. I cannot use it because I have no room to fit a steering rack behind the suspension because the V12 block is in the way.

I discovered that the MGB steering arm will bolt directly to the bolt holes left by removing the Jag steering arm. Here it is bolted in place and sharing a bolt with the Wilwood calipers.

Here is a better picture of the MGB arm with the tie rod bolted on. Initially, the tie rods were at an upward angle which would cause bump steer problems. By flipping left side to right and bolting the tie rods in from the bottom, the rods are parallel to the control arms so bump steer will be minimal.

Next up is steering angle. I did a rough alignment to zero toe then measured how many degrees the wheel turned. The wheels turn 25 degrees in either direction, which is probably enough for all but the tightest manuever. Here you can see the limiting factor, which is the tie rod running into the suspension upright.

I trimmed the offending upright and because there was a seam, I welded it back up. Now the wheels turn 32 degrees in either direction, good enough for the pivot cones we have to deal with locally.

Next thing I have to sort out is Ackerman. When turning, the two tires in the inside of a turn drive through a smaller arc than the outside tires. In the back, the differential deals with this by allowing one tire to spin faster than the other. On the steering tires, you want the inside tire to turn a little sharper than the outside tire because the arc it is driving through is smaller. In this picture you can see that my steering rack is moved forward quite a bit, and with my current steering arms, I have no Ackerman. In other words, my front tires turn exactly the same amount and stay parallel to each other at all times. I can compensate for this by giving it a little toe-out, which will make the tires drive different arcs when I am turning, but this could also wear out tires quicker and make the handling "darty".

Another fix is to move the steering rack back, like in this picture. I have not done this yet but I re-checked the steering angle with the rack moved back and the tie rods will interfere with the uprights again, reducing steering angle to 24 degrees in either direction. Stay tuned, I may notch the upright further and move the rack back.

Update: I moved the steering rack back 2 inches which forced me to re-route the oil line under the engine. Now the steering rack is almost straight across.

I had to notch the upright pieces but now I am getting 28 degrees of steering angle and finally have Ackerman!!