We went ahead and fit the transnission. Seems my tail housing is what it is. The builder measured several and they were all the same. We are 3/8" high to ERA spec so we will have to do some more fitting to get it right but at least we are getting towards working weight.
With the trans installed I have been working on ride height with the taller tires. After messing with the thing for a year I have to say the frame is rigid. We were working on something and needed the frame to move 1/8" vertically. We put a 1500 lb ratchet strap on it and then watched as force was moved around the frame but we could not close the gap. It finally dawned on me we should use a standard 3 point system to establish a horizontal plane for the frame. We used the front frame rails and the middle of the rear cross brace to establish our working plane. This puts any frame flatness error into the rear of the car. We have a very ruff measurement of .180 between the rear frame rails when sitting on 3 points.
We welded washers to the bottom of the frame so we can locate the same every time.
Once we had the datum established I went back to setting the front end up. I have run circle track analyzer hundreds of times on the front suspension. I am going to run the lower control arms parallel to the ground. If the car is lowered below horizontal the roll center drops below ground quickly which increases the roll couple. What really caught my attention was how fast and how far the roll center moves in the transverse direction. I only ran it out to 2 degrees of roll.
With the arms horizontal - if I could reduce roll to 1.5 degrees max and run 1 degree of negative camber the tire would be flat on the road at the max cornering speed. The only reference I have is Allens car. I swiped a picture of it auto-crossing and ran some lines to determine the amount of roll which appears around 3 degrees(+-?).
I am running much less un-sprung weight, more wheel rate, and possibly less roll couple so it is not an apples to apples comparison, but I am wondering what is a typical roll angle for an FIA. Is Allen's car representative in this picture?
With the 26.50 tire, 3/4" extended ball joints, and the arms parallel, the front of the car sits 4.875 (+1/8" from ERA manual) form the frame rails to the ground. I wish I could get the 1/8 back easily (CG), but I cannot see how.
Anyway once we got the thing on 3 points I realized how out of square the rack is so we pulled the car and squared the rack. Since we can start running next month we put the Mustang back on to install the splitter.
Working around the car we all notice how light it feels. With it sitting on the floor I decided to give it a cursory weigh. I piled as much disconnected stuff as I could think of into the cock pit.
No fuel - When I took possession of it, it weighed 2440 lb with a half tank.
I am encouraged -
