One of the more primitive aspects of classic Mustang and Ford cars is the leaf-spring rear suspension found on most models-dating to the horse and buggy days and usually reminiscent of riding a buckboard. Besides offering varying levels of ride quality, the rear leaf springs do a poor job of preventing axle windup during a hard start. The spring actually winds up with the torque from the axle, and when it lets go, all traction is lost.
It's not the best recipe for a street-performance Mustang or racer. With soft rubber bushings front and rear, the leaf-spring suspension also does a fairly poor job of keeping the axle centered inside the car's body. The axle travels side to side during a hard turn, spoiling steering accuracy and feel while encouraging the rearend of the car to wander. Even with a great front suspension, these rear-suspension hurdles should be addressed for a serious high-performance Mustang.
Revelation Racing Supply of Australia now offers a state-of-the-art 3-Link rear suspension ($3,500 through RRS) to fit classic Mustangs and select classic Fords. It's a far better arrangement than the stock leaf-spring suspension from both an acceleration and handling standpoint, as it precisely controls axle movement in all three planes of motion. An equal-length Watts linkage assembly locates the axle in the center of the car while firmly controlling any sideways movement. A center torque arm or traction bar attaches to the front of the differential case and prevents axle windup with its long moment of leverage. Dual trailing arms locate the axle in the front-to-rear plane, while coil springs installed over Koni shocks support the weight of the car. The OE leaf springs are eliminated entirely.
Join us as we venture to Autoworks International in El Cajon, California, where we'll see just what's involved in putting this advanced suspension system onto a classic '67 Mustang. It's an easier job than you might think.