What is it and how does it work?
Not counting tires, your suspension is about the only thing that separates you and your vehicle from the road. No matter how smooth you think a road is, it's a pretty darn rough place to propel over a ton of metal at high speed. We rely upon our vehicles suspension to cushion both our cars and ourselves from the road, or track, whichever the case may be. Suspension also serves to help transmit horsepower to the ground, letting us take full advantage of our performance drive trains. In it's most basic form, suspension consists of a few basic components like springs, shocks, and anti-roll (sometimes called sway) bars.
In our niche springs come in three types: coil springs, torsion bars, and leaf springs. Coil springs are what most people are familiar with, and are actually coiled torsion bars. Leaf springs are what you would find on most domestic cars up to about 1985 (and almost all heavy-duty vehicles). Leaf springs are strips of spring steel stacked and connected to the axle. The strips are called leaves, hence the name. The torsion bar is a bizarre little contraption which gives coiled-spring-like performance based on the twisting properties of a steel bar, something not seen very often in our hobby (except on some early '60s Chevy pickups). And coil springs are just what their name implies - springs made from a round bar of steel twisted in an upward spiral shape.
Actually, the name shock absorber is a bit of a misnomer. The correct description should actually be dampers as they actually dampen the vertical motion induced by driving your car along an uneven surface. If your car only had springs, it would bounce along the road like a pogo stick. Shocks perform two basic functions. They absorb any larger-than-average bumps in the road so that the shock isn't transmitted to the car chassis, and they dampen the rebounding action of the springs. Being velocity-sensitive devices the faster they move, the more resistance there is to that movement. They work in conjunction with the springs. The spring allows movement of the wheel to allow the energy in the road shock to be transformed into kinetic energy of the un-sprung mass, whereupon it is dissipated by the shock absorber.In the performance end of automobile suspension we're beginning to see a surge in the use of coilover shocks. Coilovers consist, as the name implies, of a shock and a coil spring together as one assembly. Most offer adjustable spring plates that can be adjusted to make the springs stiffer and looser, and adjustable damping valves used to adjust the compression damping of the shock absorber.
Coilover's are a basic component of many performance suspension systems we're adapting to our muscle cars these days. Most all aftermarket frames and frame stubs (both front and rear) make use of coilover shocks, be they used for IFS, IRS, ladder bar systems, four-link systems, and/or four-bar systems. This is mainly because standard coil springs (though they are available with either fixed constant rates or with variable rates) cannot be adjusted for varying loads as most performance coilover units can. Spring selection on independent suspensions, at first glance, seems to be a daunting task. But, in reality, it is just a matter taking some measurements and plugging them into a basic formula.
* Motion ratio at the tire is (A/B)2.
* Measure the distance from the pivot point of the a-arm to the center of the mounting point of the shock and spring combination (A). .
* Measure the distance from the pivot point of the a-arm to the center of the tire tread (B).
* For example if A=14 and B=18. Apply these dimensions to the formula as follows: (A/B)2 = (14/18)2 = .61.
* .61 is the motion ratio percentage at the centerline of the wheel and tire combination. .
* Divide the .61 into the weight at the wheel to determine the amount that the spring is holding up at that location, and select the corresponding spring.
Air Ride Suspension
Air ride, as its name implies, is a suspension system that uses air rather than metal springs to support the vehicle and control ride motions. Air springing results in a smoother ride, because the natural frequency of vibration of an air spring does not vary with loading as it does with metal springs. Air springs can be made very soft for the lightly loaded condition and the pressure automatically increased to match any increase in load, thus maintaining constant ride and handling quality. An airbag/air spring is constructed of rubber and a high strength fabric. Numerous styles, sizes, and capacity ratings are available, and their load capacity and ride height are varied by air pressure.
A sway bar (also called an anti-sway bar or anti-roll bar) is an automobile suspension device that connects opposite (left/right) wheels together and acts as a torsion spring to couple the vertical motion of the wheels on one end of the car more, and to reduce body roll in corners. When the body begins to roll, it acts on the sway bar to transfer some of the excess weight from the outside wheel to the inside one. The effect of these motions is reduced body lean and improved traction in corners. Increasing the stiffness (usually by increasing the thickness, but occasionally shifting the mounting points to provide a different degree of leverage) of the bar on one end of the car tends to increase the amount of traction of the other end during turns. Any time you alter a vehicle's ride height you change its center of gravity, and a good suggestion to compensate for the handling change is to upgrade the anti-sway bars. As a good general rule, any time you add an anti-sway bar or upgrade an existing bar you will receive a noticeable improvement in the way your vehicle handles.
A Chassisworks frame will remove up to 300 pounds of excess weight from your car or truck. Since these unique designs use a straight front crossmember, the hub width is infinitely adjustable. Now you can position your wheels at whatever width you need (minimum of 50") to maintain the correct track for your vehicle. Our exclusive adjustable upper mounts allow 3"of ride-height adjustment. These frames use Mustang II or Chassisworks fabricated spindles and our Mustang II upper and lower A-arms (available in silver-powder-coat; chrome; or plain finish) and lightweight Pinto racks. We package these components unassembled, for lower freight charges. They do not require a jig to install. Excellent instructions and assembly drawings are provided. To make at-home installation even simpler, we also offer an easy-to-use assembly fixture (Number 6706). Three frame styles are available. The 1-5/8"x.134 and 3x2x.083" frames must be tied to the roll cage with forward struts. Our rectangular frames were designed for use in street rods and Pro Street machines that do not allow forward struts to tie into the roll cage. These heavy-duty, 3x2x.120"-wall models include a 3x2" front crossmember and Mustang II rack and pinion (which is stronger than Pinto steering). Three ride heights (3-1/2; 4-1/2; & 6") are available. Chris Alston Chassis Works, 8661 Younger Creek Dr., Dept. SC, Sacramento, CA 95828, 916-388-0288, www.cachassisworks.com.
CPP's New Tubular Control Arms
Classic Performance Products' Tubular Control Arm set is designed to add 5* of caster while providing full wheel travel and minimal friction possible. They are made from 1-1/4" .120" wall D.O.M. tubing and the pivot barrels are thick 1-1/2" .188" wall D.O.M. tubing to eliminate distortion from welding and hard use.
The bushings are made from self lubricating non-squeak patented plastic that will out last any rubber or urethane, and works at temperatures in excess of 400oF. The billet 4140-alloy steel cross shafts and sleeves are zinc plated for lasting performance. The sleeves have an interlocking design that prevents the hardware from ever working loose. The pivots carry both forward and back loads (the original cross shaft pivot was designed to only carry a forward or back load, but not both).
The control arm assemblies are a simple bolt-in installation with no modification required. They work with all factory and replacement power steering systems, and with or without O.E. bump stops.
Classic Performance Products, Inc. has been providing the classic Chevy and Ford truck, as well as Chevy passenger car market with top quality steering, brake and suspension components for the last two decades. Call and order a catalog today, featuring our complete line of parts and accessories. Classic Performance Products, 175 E. Freedom Ave., Dept. SC, Anaheim, CA 92801, 714-522-2000, www.classicperform.com
Tubular Lower Control Arms
Detroit Speed and Engineering has superbly engineered tubular lower control armsTo replace the stock lower arms on 1967-1969 Camaros and 1968-1974 Nova's.
These new arms are shipped complete With the steering stops and the lower ball joints ready for you to install on your car.All you need to do is to follow theInstallation instructions. It's really that easy!
Features of the arms include a sturdy tubular design with gussets and cross brace, Delrin bushings with steel housings and crush tubes and a durable baked on black powder coated finish.
The improved geometry features include additional positive caster and a dropped spring pocket as compared to the stock arms. These lower arms are available with either a conventional lower Coil pocket or a double shear mount for DSE's coilover kit.
These arms will not only improve your handling, but they're going to improve Your look as well!
There's only one additional thing to be said: You're never going to be disappointed with a Detroit Speed product! Detroit Speed & Engineering, 185 McKenzie Rd., Dept. SC, Mooresville, NC 28115, 704-662-3272, www.detroitspeed.com.
For "G-Force Spindle" For GM Muscle Cars
Hot rodded muscle cars are hotter than ever, but the demands of modern traffic have made their chassis shortcomings all too apparent. The sad truth is that most modern family cars can out handle and brake our beloved '67-'69 Camaros, '68-'74 Nova, and '64-'72 Chevelles, but easy bolt on help is available! Fatman's new G-Force spindle provides a 2" drop for a lower center of gravity, and has the upper ball joint raised 2" to obtain the improved camber curve necessary properly plant those wide, sticky modern radial tires. A 20% improvement in skid pad numbers has been observed. The steering arm position has been optimized to eliminate bumpsteer. Any disc brake system that fits the stock spindle will fit these new ones, so the sky and your wallet are the only limits to improved braking. The G-Force dropped spindle will align properly with either stock stamped control arms, or Fatman's tubular arms, in either stock width or narrowed versions. Upgraded shocks, springs and sway bars are also available to further the improvements. A couple hours work will transform the handling of your muscle car-it can handle as good as it looks! For more info, contact the Fatguys at 8621-C Fairview Rd, Hwy 218, Charlotte, NC, 28227-7619. (704) 545-0369 or www.fatmanfab.com