As you can see, the 'ol R/T...
As you can see, the 'ol R/T is planting the tires solidly across the pavement, the front end is rising, and we are on our way to another 12-second time slip. Common sense will let you set up your street/strip car as well.
It goes without saying that the Chrysler Corporation designed some pretty solid engineering into the OE suspension of our beloved Mopar vehicles. The front torsion bar/rear leaf spring suspension earned the '57 Plymouth Motor Trend Car of the Year honors in the year of its debut. As the musclecar era developed, this combination proved more than capable of dominating on both circle track and straight-line competition circuits, and it is not surprising that today's popular V8 SUVs continue using a torsion bar/rear leaf combination in many cases.
With more and more of us driving our cars these days, we thought it would be a good idea to give some basic information on some changes that can be made to your suspension for either track time or handling chores. Of course, there is always a fine line as to what type of end result you are trying to achieve. For example, removing front-end weight is important in drag cars, but making sure the vehicle can still go around corners, especially in dual-purpose machinery, is an even more critical aspect. Here are a few things you might want to consider as you put together your own dream machine.
Here is the frontend of Rick...
Here is the frontend of Rick DeMarco's California Flash '65 Super Stock Plymouth, which has run in the low 10s at 130 mph. Since this is a strip-only car, 90:10 shocks and six-cylinder torsion bars help. The 90:10 shocks are hard to compress but easy to extend, aiding in frontend lift. Be sure to get a good frontend alignment; for drag cars, a good shop can do this with the nose raised an inch to minimize friction while the car accelerates down the track.
Sway Sense
Front and rear sway bars were not part of Chrysler musclecars until the debut of the T/A/AAR Trans-Am E-Bodies in 1970, the first vehicles to employ both. Front sway bars were part of many musclecars starting in the mid-'60s, although garden-variety machines didn't utilize them. In 1971, the factory began adding a rear sway bar as part of the differential package on many E- and B-Body cars. As for A-Bodies, rear sway bars were rare; the only one I remember seeing was under a '76 police car.
Today, there are aftermarket sway bars available for most of the muscle-era cars; check out Mopar Muscle suspension advertisers for your application. These are normally 1/8-inch to 1/4-inch larger than the OEM versions. Simply going from the rubber to polyurethane bushings will show an increase in handling ability as well, something that is very important in any big-block car. Renewing the bushings in shocks, control arms, leaf springs, and strut bars will also aid you here. Just remember to disconnect the stabilizer bar links when hitting the drag strip so the front suspension can transfer weight properly.
Torsion Trials
For many people who drag race, one easy switch is to change from V8 to six-cylinder torsion bars under the frontend. Removing the torsion bars is a fairly simple mod, but be sure to consider what you plan to do with the car. If it's more street than strip, the V8 bars were designed to help the frontend take road abuse.
What's missing here? Answer:...
What's missing here? Answer: the stabilizer bar links and bushings. This makes a big difference in frontend rise and 60-foot times, and it is done at the track. Since the car sees street time, I simply use a set of regular-duty hydraulic shocks (as opposed to the OEM heavy-duty units), and these simple changes help the car to hook on 28x9-inch slicks without wheelspin.
The A-Body line from 1963-1976 used a 35.8-inch bar, while '62-'72 B-Bodies and all E-Bodies used a 41-inch bar. In bone stock form, the bars' thicknesses ranged from 0.83-inch to 0.96-inch; circle track machines requiring stock-style suspensions had bars as thick as 1.25. The aftermarket offers many varieties, and you might even get a set from the boneyard. Replacing torsion bars is not a matter to take lightly; consult with suspension aftermarket people and other knowledgeable sources of information. The ones who know what they are doing will talk to you. The facts that you should have ready are rear spring stiffness, engine and vehicle weight, tire and wheel sizes (front and rear), and other specifics.
While we are on the subject of front suspension and weight, lightening the weight ahead of the cowl is an easy way to get better launch and handling characteristics. Power steering pumps and related equipment can add as much as 50 pounds to the car (though, again, since both my Challenger and my R/T are street driven, I have left them in place). Adding aluminum heads and intake, an aluminum water pump, moving the battery to the trunk, and other tricks can bring the car into a much better front-to-rear weight ratio. For serious street/strip cars, manual steering is the way to go. For those who want to go around corners, there is also the optional 16.1 fast ratio steering box; the standard version is 24.1.