Originally I had a Jaguar independent rear end that came with four coil over shocks. I sold the rear end and kept the coil over shocks. This was part of the package that came with the 1931 Ford Model A 5 window coupe I previously purchased and sold. I found that these shocks had a perfect distance between the mounting holes and seemed to have the correct spring rate for the front of my 1929 Ford Model A hot rod. My intention is to use these coil over shocks temporally till I generated more funds for some nice chrome or aluminum coil over shocks.
The lower shock mount is basic. I used a triangle pattern for the base of the shock mount. A couple of half moon shaped brackets were welded to the base of the lower shock mount. All of these pieces where fabricated from 0.25 inch steel plate and cut out on my metal cutting band saw. To make sure for a perfect fit, I bolted the half moon brackets to the shock, and then positioned the shock with brackets onto the lower shock mount base. This was then tack welded in place. Once I was happy with the position and fit of the shock, the half moon brackets were permanently welded in place. This assembly fits perfectly into the lower control arm from the C4 Corvette. Another consideration for the lower shock mount is to fabricate one from 2 inch stainless stain square tubing and using small spacers inside to make up the difference between the width of the shock mount and the opening of the bracket. I am leaning more towards this style considering that I will eventually polish all of the aluminum suspension parts and use chrome coil over shocks.
With the lower shock mount placed onto the lower control arm, I started to examine various mounting options for the upper shock mount. Very quickly I realized that I could create a much smaller mount just under the mounting bar of the upper control arm from the C4 Corvette. The only concern I had was that the angle of the shock was increasing slightly. The correction factor when mounting shocks on a 15 degree angle is 0.93 and for a 20 degree mounting angle is 0.88. This is approximately the change I wanted to introduce to the suspension. So to check things out, I was able to set the upper shock mount temporarily. I added a few sand bags as extra weight or ballast to compensate for parts still not on the chassis. Then I positioned my 250 pounds onto the chassis. I took a resting position measurement and another one when I started to bounce up and down on the chassis. This activity resulted in only a 1 inch movement in the suspension at the best of times. This seems reasonable to me so I then decided to create a second version of the upper shock mount. Once again to ensure a perfect fit, I bolted the newly fabricated upper shock mounts to the shocks. The complete coil over shock assembly was then fitted to the chassis. With everything in place, the upper shock mounts were tack welded to the chassis. Making sure that this was what I wanted this time and that the mounting positions were correct, I removed the upper control arm and shock for the final welding process of the upper mount.
Standing back and looking at the new version of the upper shock mount, I felt the entire process was well worth the time and effort. In my mind the design was much cleaner looking. This outcome is in line with my over all goal with this project. It is to build a good looking, safe, and, have great handling characteristics hot rod with a minimum of expense. So far, I am right on track.
Tags: C4 Corvette hot rod suspension, front coil over shock mounts, Front lower coil over shock mount, Front upper coil over shock mount, hot rod front suspension, jaguar coil over shock, mounting shocks for the C4 Corvette IFS, spring rate correction factor