After some manipulation with a hammer and dolly, the flange on the torque box is welded. N
Calculating the center of gravity (COG) of any car is difficult, and there are several methods available, but they are complex and require weighing the car and then lifting one side and measuring the changed weights. One formula for deriving an approximate CGH (center of gravity height) looks something like this:
CGH = (WB × FWc) / (TW × Tan)
WB = Wheelbase (inches)
TW = Total Weight
FWc = Change in weight when one side of the car is raised
Tan = Formula based on the height one end of the car is raised
For our purposes, a lower COG is always better, because a lower COG minimizes the leverage the sprung mass has on the unsprung mass, helping to keep all four tires equally loaded. The easiest way to the lower the COG is to lower the vehicle itself.
We know that lowering a car does more than improve its looks, but what methods are available? The most common way is to replace or cut the springs. That lowers the whole car and is the best way to get biggest change in COG, since all the mass in the car has been lowered. Another similar method for front suspensions on some cars is to install drop spindles. It accomplishes the same thing: it lowers the whole mass of the car. But both methods have a big drawback: they reduce the space under the car, putting the face of terror on mundane things like curbs, speedbumps, and driveways. Lowering springs also compromise your suspension geometry, since most suspensions are designed for their "sweet spot" at the factory ride height, and you lose a big chunk of the sweet spot when you drop it in the weeds.
On Unfair, we're raising the floor into the passenger compartment. That means that all the outer sheetmetal is lowered around the car's suspension and drivetrain. We won't get the full effect on our COG since much of the car's weight stays where it was, but we also aren't going to compromise our ground clearance or suspension geometry. Some might call this method "channeling," but since we're not moving framerails up into the floor, it's not quite the same.
With a vehicle weight around 3,000 pounds, and an outer sheetmetal weight of about 1,000 pounds, we are lowering one-third of the mass of the car. Our COG movement will be about one-third of what it would be if the whole car dropped, but we will make that trade for a more enjoyable driving experience.
It also makes for a better car-building experience since all the components will still bolt up at the factory locations. We've got an awesome Art Morrison Enterprises subframe on order, and it will bolt right up. Between the lowered ride height built into the AME subframe and the raised floor, we expect to lower Unfair's COG by 2 inches.
II Much Fabrication
Auto Metal Direct
940 Sherwin Parkway