Here is my new/remanufactured Chevette rack. It is about 4" too long for the chassis. The input shaft rides up against the front upright tube for one thing.
Bump steer is the other issue.
So I've decided to cut it down.
It's all apart here, pretty simple really. What was I worried about?
I've marked the body with tape 4" apart and have hand bandsawn it apart on the lines.
Here is the reassembled rack ready to install in the car.
This is the shortened parts along with the 4" pieces removed.
I found a motor shop who does welding on Aluminum heads and they welded up the body for $30. You have to be careful that the rack still moves after welding.
This is the custom adaptor plates I had made to change the Chevette lug pattern to match the Supra pattern.
These are the 85 supra wheels I'm usisng
The fronts are 14 by 7" and the rears are 14 by 8" wide. I'm using 215/14 on the front and 225/14 70's on the rear.
Should be more than enough rubber on the ground for 200 HP.
I polished the rims and repainted the centers on these wheels. Paint and everything about 50 bucks each.
15" wheels would give a lot more tire choices though.
Here's a few new shots of the steering installed in the chassis, showing how I mounted everything.
All of the steering components are from a Chevette. I'm ordering a Mahogany Grant steering wheel next week.
Here's the shortened rack installed. I'm sure I'll still have some bump steer issues to work through in a few days as I install the suspension again and make adjustments.
I've been in Houston for a week but my steering wheel arrived while I was gone.
It's a Grant 13" Mahogany wheel.
Grant has a kit to adapt it to the Chevette column which is the same as any Chevy column. Every thing from that 1/8" gap forward is the mounting kit.
I'll give a description of how I adjusted my steering while I put everything back together.
First I remounted the lower arms then shimmed out the upper arms to get both a plumb reading on my level off the machined base of the spindle and getting about 7 degrees of caster angle so the steering wheel should self return OK. While I was welding the chassis I moved the lower mounts forward 3/8" to help get that 7 degrees.
All good so far.
Then I cut two sticks to level the lower arms for ride height. the upper arms have about 1/2" of downward angle but it doesn't show in this shot
I just used a simple stick to mark the measurements both front and back while adjusting my tie rod ends until both readings were exactly the same. Now the wheels will be parallel to the chassis.
Then I put 2" blocks on top of the leveling supports to raise both sides to a 2" bump reading and checked the front distance apart using my simple stick again. I found that I had a bump steer reading of about an 1 1/2" total or 3/4" for each wheel, toe in. After looking at it for a while I decided that it should read better if I moved the rack back and up a 1/2" on my angled mounting blocks, so I did that.
That did help. I'm within about 3/8" of tow in at 2" of bump per wheel, and at full droop about 3/16" of toe out.
I know this isn't perfect but my rack is about 1 1/2" long still and the mounting points for it are at 6" apart on center. I was afraid to go much shorter with it for stability of mounting. A compromise.
This is a seven, and on a street car I think the bump steer should be hardly noticeable. I think that is a small amount but I could be wrong, I suppose.
So this just took me about 2 days but I think everything is in pretty good alignment. We'll see when I get to drive it.
One of the first things I did was do a quick bump steer check with the tie rod ends in the proper position. They are supposed to mount underneath the spindles. Serious toe out. So I tapered the holes from the top and mounted the tie rod ends that way, much better. A bit of toe in. The books say that if your' not perfect toe in is better than toe out.
Next I cut and machined these two sticks and screwed them to the machined surfaces on the spindles one on each spindle, so I could get the spindles parallel.