We are testing 5 different 500 pound springs to see where they are different and how they respond. We will be doing 2 tests the 1st one is a standard spring test (1+1") as we have been tough over the years. The 2nd one is on a test bench where the spring is in a control arm and moved through the motion ratio the car produces. We will also look at the springs in both compression and rebound.
Here is compression and rebound per .200 of travel from 9.400 to 7.0", you can see some difference between springs. The Eibach is the lightest as it is going down through the travel and I don't think there is a problem at all. BSB spring is just over 9" tall is why we start where we did. All springs look good in both compression and rebound.
Rate change in the spring as it traveled down every .200, the Afco spring showed a rate change at 7.2" but that is an error in the math formula and should be 100 pounds. The Landrum also showed an error at 8.4" which should be 105 pounds.
The above chart is the number of coils and the open close of the spring. The top and bottom spring spacing will dictate when the spring stops making rate, this is important to the outcome of the spring.
The bench test is where it is going to matter because, at the end of the day, we want the car to stay off the race track. The 3" numbers all look the same it is just softer getting there. I feel like this is going to be up to the guy running the load stick as to what he thinks is going to work. So by looking at the number, it is not going to tell you which spring is better and it is still going to come down to how it is made.
Here are the data sheets that we did not get in the video, and they include some more info about the springs, unfortunately, we can't determine the manufacturing practice used to build the springs, which is going to be the biggest factor in how they turn out.
Added 3/20/2024