D81: Steering Rack and Column Updates

With the newly redesigned front suspension I needed new mounts for the steering rack. Below is the design for the new mounts. From the previous post, I knew how high above the lower control arm pivot I wanted the center of the rack to be and from the original design I knew how far in front of the front cross bar I wanted the rack to be. Thus, the design below.

Below is one of the two mounts for the steering rack that will attach to the front cross member.

Both mounts tacked onto the front cross member and the steering rack in place.

The new design I have for the steering column required a few mods to the firewall. The first was installing a firewall mount for the steering column. I replaced part of the firewall with this 1"x2" piece of tubing.

With the firewall mount in place, I wanted to make sure the the column cleared the brake booster. From the pick below, there is plenty of space.

The new steering column connected to the steering rack. Getting rid of the extra piece of linkage makes for a clean install. I also think it'll be a safer/stronger design.

The last pic is the steering column next to the pedal assembly. The new column will come almost directly out at the driver instead of the previous design where the column was at an angle. Again, a cleaner design.

D79-80: Suspension Redesign and Rebuild #4

I've spent the past week redesigning the front suspension yet again. After getting the last design tacked together I realized that bump steer might be an issue. I did a little research and modeled my design in CAD to realize that, YES, I did have a bump steer issue.

The design below is what I've come up with for the (hopefully) last build. I've raised the steering rack and plan on mounting the tie rods to the top of the spindle instead of the bottom. This allows for adjustments to control bump steer. I need to modify the spindle and build custom tie rods to complete this conversion.

The new design brought the mounts for the lower control arms in about 1.5" on each side. Below is the design for the new control arms. I've gone back to the style of the second design maximizing the steering range. This won't cause the same issue I ran into with the second control arm because the tie rod is on top of the spindle mount and won't hit the rim.

I built the new arm on the frame. It was easier to tack the mounts and build the control arm on the frame than trying to build a jig for the arm. I did the same on both sides and I'm much happier with the latest build than with the previous one. There is much less slop. I also plan on adding some additional plates to strengthen the mounts.

D73: Lower A-Arm Redesign #4 + Steering Rack Mount Rebuild

Yesterday I had another realization... the new a-arm design allows the wheels to turn fully outward, but now the wheel hits the steering arm when turned in. After for most of the evening I sat down and redesigned the lower a-arms for a 4th time.

Below is the latest and hopefully greatest design for the lower a-arm. I've done a few things with the design this time.

• I went back to the right triangle shape. This more closely emulates the donor setup.
• I've also kept the width the same as the last set to keep the full range of wheel motion when the wheel is pointed out.
• I've measured the distance that the ball joint is moving forward to plan for enough clearance for the steering rod when the wheel is pointed in.

With these changes and the change to the steering rack mount, I've moved the steering rack 4 1/2 inches closer to the ball joint. This should give me full range of steering motion in both directions.

Lower A-Arm Design #4.

As I just mentioned, I also made a change to the steering rack mount. I cut out a section so that the steering rack could slide back closer to the mount. This moved the rack 1 inch closer to the mount helping achieve the 4 1/2 inch difference mentioned above.

Recessed notch for steering rack.

Steering rack installed in mount.

I plan on installing the modified mount about 3 1/2 inches further back to keep the wheelbase the same as it was with the previous a-arms. This also means no rework on the upper a-arms. It'll move the rear lower a-arm mount behind the upright similar to the first (or second) design.

Steering rack mount in the frame.

D44:Steering Rack Mount Supports

Take 2 of the steering rack mount supports/control arm mounting point supports. I think these will do a better job than the first iteration.

D43:Steering Rack Mount D2 and Front End Mods

The front cross member is almost complete. In the second pic, the ends of the tube have been cut and drilled to mount the control arm (planning on 1/2" bushings). The lower steering rack mounts have also been welded on. My one concern with this is the main tube is only 16 gauge and I'd like something a little more substantial to hold the control arms, so I'm playing with some different ideas of how to strengthen the mounting points. My first trial is the third pic. The idea is to weld supports on both sides of the each end.

While fitting the front cross member I realized I wasn't very happy with how everything was "fitting" in the front end, so I decided to a little more deconstruction and reconstruction. I cut off part of the front and then moved the forward most a-arm vertical tubes and angled them back from the lower front to the upper support that I added a few months back. I'm realizing this doesn't make much sense so just take a look at the last couple of pics and compare them to the last engine fitting post pics to see the changes in the front end.

D42:Steering Rack Mount and Lower A-Arm Mount

I'm eager to get this project to the "roller" stage, so I'm going to start working on control arm mounts and steering rack mounts. If you remember from a few months ago, I was going to use the donor front cross member but then decided against it. Here is the new solution to that.

Using a piece of square 2" tubing, I'm going to mount the steering rack to the front and then use the ends as the front lower control arm mounts (more to come on this). The second pic is the progress so far with the top steering rack mounts fixed. A couple of design comments about this approach. First, the control arm mounts will be at the exact same width and position (looking from the front) as the pivot points on the steering rack. This allows me to mount the upper a-arms anywhere without having to worry about steering rack width and positioning which can lead to bump steer and number of other issues. I'll try to post a diagram to represent this at some point. Second, it allows me to use the donor rack without any mods to the rack or the front uprights.

In case you were curious what the original front sub frame looked like in comparison to the new one, it's in the second pic.