This is Matt Hatfield, driver of the Wagons of Steel '70 Chrysler Town & Country Sportsman bracket car. He's a freshman racer so he still has fun doing anything at the drag strip. He didn't mind that the car he was driving was very inconsistent, he was just glad to be there but it bugged Dr. Big Block and me. We wanted to give him a car that he could win with. We knew that the likely source of the problem was the 38 year old leaf spring suspension. I had reached that conclusion when I ran it down the track a few times last year. I had installed headers and tuned it until it could do heroic John Force style burn offs and hit almost 90 mph on the big end but it was impossible to get traction, never mind predict the ET or cut lights reliably. As Matt soon found, it would run either mid fifteens or low sixteens. Dialing in a car to run 16.25 that might run 15.60 is an impossible challenge to any bracket racer.
Here is the culprit. It's tired like the timing chain we replaced and equally unglamorous to fix. The helper springs are a dead giveaway of a tired suspension. At least they aren't dead air shocks. Suspension that doesn't work makes anything else that you do to the car worthless or even dangerous. The traditional leaf spring system does work well but it has to be set up correctly for the job that it's supposed to perform. With a more commonly hot rodded "A" or "B" body car, the first step would be to get a new set of performance leaf springs because they're relatively cheap and easy to install but we don't have that luxury with a big "C" body. New springs are rare and always set up for comfort and/or towing. We had to figure out an alternate solution.
A complete custom CalTracs suspension system would be a viable and relatively affordable solution although even that was not in our budget at the time. This is the CalTracs system on our B/SA car. It's a split mono leaf spring with CalTracs traction bars. It prevents the housing and the springs from winding up when the car launches. Check out the super reinforced housing that we bought after we first installed this suspension. The power of the launch twisted the tubes and almost ripped the perches off our original stock housing. It also cracked every tooth on the ring gear. Welcome to my world.