DMR Rear Suspension Upgrade For Musclecars - Classic Muscle Car - Tech

With all the rearend components in place, the first step was to make sure the axlehousing was square in the chassis. A simple measurement from a forward crossmember to a mounting point on each side of the housing ensured it was square. A measurement from the axle flange to the centerline of the car established that the housing was also centered in the car.

You want zero pinion angle when the car is accelerating, so depending on how much torque the car makes, you need to set the negative pinion angle using both upper control arms. The rule of thumb is 1-2 degrees of downward angle for a four-link car sitting on a flat surface. If you are making a lot more than 500 hp, the angle should be increased until you achieve zero angle at launch. Too much negative angle wastes horsepower.

Preload is set with the passenger-side upper control arm by drawing the corner of the housing up into the car and adding weight to that tire. If the car pulls right on the launch, shorten the control arm until it goes straight.

The front suspension was left stock except for the addition of Strange single-adjustable shocks. These shocks have an oversize diameter, so the shock opening in the lower A-arm needed to be enlarged.
The front suspension was left stock except for the addition of Strange single-adjustable s
At the track, chassis guy Mike Moran started out with six clicks on the single-adjustable front shocks and set the double-adjustable rear shocks at three clicks on compression and three clicks on rebound. We then watched the launch on videotape. If the car transferred weight before the rear end lifted on launch, the shock was doing its job. A stiffer shock slows the transfer of weight, a soft shock speeds it, sticky tracks require a stiffer setting, and slippery tracks require a softer setting. Moran wrote notes on the shock with a Sharpie pen detailing the adjustments for each run. On the fronts we ended up at five clicks clockwise. On the rears, we stayed with the initial setting.
At the track, chassis guy Mike Moran started out with six clicks on the single-adjustable
After several adjustment runs, the car hooked hard and ran a 1.57 60-foot without pulling to one side or the other. After two more 60-foot runs to check consistency, we pulled the trigger and ran an 11.59 at 114 mph.
After several adjustment runs, the car hooked hard and ran a 1.57 60-foot without pulling

Special thanks to Milan Dragway for track time and Wheel to Wheel Powertrain for chassis dyno time! We couldn't have done this story without their help.