Suspension Bushings
Bushings provide a cushion at component mounting points and they allow suspension parts to pivot without transmitting noise or vibration to the cabin, or requiring lubrication. Most OE bushings are made of rubber, which absorbs the vibration, and flexes to allow movement. However, this flexibility allows excessive play in the suspension system, adversely affecting handling and traction when the vehicle is driven aggressively. Our polyurethane and Delrin performance bushings, and metal spherical bearings, eliminate deflection for more responsive handling and acceleration without wheel hop.
Bushings are used where the body mounts to the frame and where subframes mount to the body, and where components like steering racks and differentials are mounted to the frame or body, to isolate the cabin from shock, vibration and noise. But in addition to their cushioning properties, bushings can also twist and return to their original shape many times before they wear out, making them ideal for use on suspension parts that pivot like control arms, leaf springs, shock absorbers and sway bars.
Original equipment-type rubber bushings are fine when a soft, quiet ride and factory quality handling is desired. Rubber is softer and more compliant than polyurethane, Delrin, and metal, allowing it to absorb more shock and vibration. Rubber supplies more cushioning than performance bushing materials and tends to operate more quietly, for a smooth, silent ride. Rubber bushings are perfectly adequate for repairs or suspension rebuild jobs on a stock vehicle that won't be driven aggressively. They're entirely acceptable when factory like ride and handling, and original equipment level performance is preferred.
However, the same qualities that make rubber bushings great for stock applications make them inadequate for high performance use. Rubber's compliance allows too much flexibility in critical joints when a vehicle is driven hard. When the steering wheel is turned or a control arm or shock absorber moves, part of the motion is used up compressing the rubber bushings. Instead of one part moving directly in response to another, there is a momentary hesitation while the rubber compresses before the part moves, commonly called bushing deflection. The result is steering and handling that is mushy and imprecise.
Bushing deflection can also cause wheel hop during hard acceleration, such as when launching from a dead stop in a drag race. When power is suddenly applied, bushings in the driveline like differential bushings and in the suspension like those at the control arms, can permit excessive movement, which can allow the tires to gain and lose traction repeatedly, the phenomenon known as wheel hop. Wheel hop not only impedes acceleration and loses races, but when it's severe the rapid loading and unloading of the drivetrain and suspension can result in broken parts.
In contrast, the performance suspension bushings we offer are much more rigid than rubber. Polyurethane is the most popular material. With polyurethane, while the vehicle ride can be firmer, handling will be much sharper and steering more precise. Connections between suspension parts will be more direct, and the suspension will be more perfectly aligned. When you turn the steering wheel, the car will turn directly in response to your input, and when you mash the pedal, your tires will be planted and you'll get all the power to the ground. Polyurethane bushings will also last much longer than rubber because they're impervious to environmental conditions like heat and contaminants like oil that usually cause rubber to deteriorate.
While somewhat more expensive, for some applications we can offer you Delrin bushings. Delrin bushings provide metal bearing type rigidity, without any friction that could inhibit articulation. For racing applications where zero deflection is desired, we have steel and aluminum body and subframe mount bushings and spherical bearings, commonly called Heim joints, for suspension components. Spherical bearings are ideal where rigidity with increased articulation is desired, particularly in applications where bushings could result in binding. Many of our polyurethane and Delrin bushings are greasable, to prevent noise and ensure free movement, and offset bushings are available for some applications, to provide additional alignment adjustment range.