Muscle Mustangs & Fast Fords
1993 Ford SVT Cobra Rear Suspension And Rear Axle - Straightening the Slithering Part 2
Project Stolen Goods gets rearended and suspended.
Maximum's front control-arm bushings have a hard centersection to prevent fore and aft deflection, and softer outer sections to allow the angular motion necessary to prevent bind. These three-piece urethane bushings are employed at the chassis end of the arm, rather than at the axle end to reduce noise, vibration, and harshness. Placing them there also keeps the control arm and chassis from getting too far out of line with each other.
The MM heavy-duty adjustable lower control arms we're using allow us to raise the rear ride height up to 2 inches or lower it as much as 1 inch, thanks to its weight-jack bolt, a piece similar to what NASCAR race cars use.
As for the upper control arms, Maximum does not recommend using urethane in the upper arms to restrict the side-to-side motion of the axle. "Because of the three-dimensional movement of the upper arms, severe binding will be induced as the suspension moves-with or without a Panhard bar," Schwynoch says. "This effect may not be evident in a drag-only car, but if you plan to drive the car on the street at all, we do not recommend urethane in the upper arms."
That being the case, we'll reuse the stock upper control arms for the time being and ditch them later on down the road when we install the torque arm. Until then, and after, we'll use MM's Panhard bar to locate the rear axle assembly. In relying on the four control arms to locate the axle, Mustangs can experience unstable and unpredict-able handling behavior while cornering near the limit. This is caused by the rear of the car moving sideways and attempting to steer itself without any input from the driver.
There are a couple of companies that offer large aftermarket sway bars to reduce body roll. When we queried Schwynoch regarding what to use on Stolen Goods, he replied, "The '93 Cobra sway bars are the best." Unfortunately, they weren't in our pile of parts that we grabbed with the car. We then asked why he liked the Cobra bars so much.
"The smaller-diameter Cobra front sway bar will result in a car with less understeer and better braking traction, especially on rough surfaces," Schwynoch says. "The stiffer the sway bar, the less independent the suspension acts. Bumps hit by the left front wheel result in suspension motion in the right front suspension. Very stiff sway bars, like the stock GT bar, are Band-Aids for springs that are too soft."
According to Al Kirschenbaum's The Official Ford Mustang 5.0: Technical Reference & Performance Handbook, '93 Cobra's stabilizer bars measure 1.125 inches in diameter in the front versus 1.30 inches for the stock GT, while the rear stabilizer bars are the same 0.83-inch diameter from Cobra to Mustang. The Cobra also received stiffer bushings in its stamped rear upper control arms.
Luckily, Stolen Goods' previous owner had the '93 Cobra sway bars stashed in his garage, but before we could mount the rear sway bar and Panhard-bar setup, we needed to get the 8.8 axle fixed up for extreme duty. We called the folks at Reider Racing and told them we had a housing and that was it-we needed everything from axle seal to axle seal.