The one thing I would definitely not recommend, though, is a welder that uses flux core wire. The welds are not as strong and don’t look as good either. My welder is currently set up to use .024” wire and “gold gas” and once you find the right settings it does a wonderful job other than the general lack of skill the operator (me) possesses. I kid! It’s what I do.
Most of the material I am working with is normal low carbon tubing and a Mig works just fine and is much quicker and easier to use if you work alone like I do. However, some of the steel is made from 4130 chrome moly and it must be welded with a Tig welder which uses a “stinger” made from a tungsten material and Argon gas. The fill rod is fed into the weld by hand, almost like brazing with a torch, but the weld is much better and stronger. So, now that we have the tools covered let’s get to it!
 This is a pretty good glimpse into the look I'm going after. Super Stockers have a floor pan height specification that prevents the car from being slammed to the ground but I think I can get pretty close. I like it! |
 Instead of completely removing the rear floor area in one big chunk I surgically dismantled it with a air chisel. Mostly because I wanted to see what kind of shape the old torque boxes were in. They weren't good. Cracking of the sheet metal boxes was evident and it wouldn't have lasted long. Good time to start over! |
The first step in a back half project is to determine your goal for the car when completed. In racing setups there are basically two types of rear suspensions used today. The first and by far simplest is the traditional “ladder bar” which has a single pivot point at the front and bolts solid to the housing. It works amazingly well in most instances and is fairly adjustable as far as being able to change the pinion angle, and by either raising or lowering the front pivot you can dial more or less “bite” into the rear suspension.
The drawback with a ladder bar as I see it is the that because the length of the bar is fixed and the range of adjustment is fairly limited, you can run into situations where the car reacts so violently at launch that it either blows the tires off or tries to flip over. The relative lack of adjustments and violent tendencies increase as the horsepower increases and the track gets slimy in the summer.
The ladder bar can work amazingly well for most cars and most people don’t need anything more, but if you do need more adjustment (or at least think you do) then you go with what is called a “4 link.”
I just about went with the ladder bar but honestly the work involved to install a 4 link isn’t that much more, the range of adjustment is nearly unlimited, it adds resale value to the car, it works great, and, hell, it looks cool too! This isn’t the first car I have ever “tubbed” and believe it or not I have in the past even made my own 4 link including the mounting brackets and bars, but now that I am a little older and wiser I can't believe I went to all that work to save a few bucks. It was a good learning experience though. For what you can purchase a quality 4 link for today it wouldn’t make any sense to me to do otherwise. Actually, the rod ends or (Heim) joints cost as much as the 4 link!
So, with a basic plan of attack I grabbed my Moroso /Competition Engineering catalog and made a list. Comp Engineering has two different 4 links available and I went with the top dog “Magnum” 4 link (part #C2028). The Magnum kit includes the chassis and housing brackets that are stamped from ¼” thick steel for more strength and resistance to flex, huge chrome moly 1 3/8” lower and 1 ¼” upper link tubes that use threaded weld end inserts as opposed to direct threaded 1 in. tubing found in other lesser kits, and have 5/8” adjustment holes instead of the more ordinary ¾” holes found in the more basic 4 links. The smaller 5/8” holes allow for more holes in the same space, which allows more fine adjustment of the suspension. The housing brackets also incorporate a built-in lower coil-over mount, upper wheelie bar or, in my case, anti-roll bar mount, and some 1 ¼” holes for additional gusseting.
Man, if you can bend or break this 4 link you are doing something! The mounting bolts and additional metal strapping for reinforcement are also included. The rod ends are not included and you need to buy the proper units depending on the usage they will see. In my case I got the super strong chrome moly ends that come in right and left handed threads for easy adjustments of the 4 link bars. The part #’s are C6160 RH and C6161 LH and four each are required. Rod ends are definitely no place to try to save a buck. Buy the good ones!