Q:
Swing ArmA:
Simple independent suspension of 1 lateral link rigidly connected to the wheel (early VW Beetle). With this design, wheel camber changes radically through the suspension stroke.Q:
Anti-DiveA:
Anti-dive is a suspension characteristic that affects the amount of suspension travel when the brakes are applied. When a car is decelerating due to braking there is a load transfer off the rear wheels and onto the front wheels. Vehicle properties such as the center of gravity height, total weight, deceleration rate and wheelbase affect the amount of dive a vehicle experiences. 100% anti-dive refers to no change in front suspension height under braking. This is achieved by adjusting the pivot points of the suspension system or through hydraulics in the front dampers.Q:
Anti-LiftA:
Rear suspension kinematic characteristic which reduces the amount of pitch under braking forces. Street cars may have up to 150% anti-lift for driver comfort.Q:
Anti-SquatA:
When a car is accelerating forward, there is a load transfer off the front wheels and onto the rear wheels. Vehicle properties such as the center of gravity height, total weight, acceleration rate and wheelbase affect the amount of squat a vehicle experiences. 100% anti-squat refers to no change in rear suspension height under acceleration. This is achieved by adjusting the pivot points of the suspension system or through hydraulics in the rear dampers.Q:
Anti-Roll Bar (aka: stabilizer bar, sway bar - from anti-sway bar)A:
A transverse torsion bar linking both sides of a suspension system with bushings mounted on the chassis that allow it to rotate freely. The bar's ends are connected to or shaped as lever arms, with attachments to the suspension linkages at each side via ball-joint links, rubber-bushed pivot links, or as on race cars, spherical rod ends called Heim joints. When both wheels take a bump equally, the wheels move the same amount without twisting the anti-roll bar. Individual wheel movement or body roll will force the bar to twist as the lever arms are moved, thereby adding the bar's own spring rate to that of the car's springs. Although an anti-roll bar's main function is to reduce body roll in cornering, it also influences overall handling. You can fine-tune Over- or Understeering Tendencies.Q:
ApexA:
The geometric center and innermost point of a turn or corner on a roadway or race course.Q:
BalanceA:
Description of handling characteristics of a vehicle, describing understeer, neutral, or oversteer.Q:
BallastA:
Weight added to a vehicle usually to bring it to a minimum weight requirement-useful for adjusting balance in racing vehicles.Q:
Bar RateA:
Torsional stiffness of the antiroll bar (or torsion bar), either at the drop links or at the wheel's contact patch. This is usually expressed in N/mm or lb/in.Q:
Bell CrankA:
Linkage component with a central pivot and multiple link attachment points. Usually used with inboard suspensions to transfer loads from the pull/push rod to the spring/damper. Technically, a "rocker" uses the same pivot for pullrod and damper, while a bell crank has different attachments for each.Q:
BumpA:
Vertical movement of wheel towards chassis. Aka deflection, jounce. In racing, the terms "bump and droop" are used together to define suspension travel. For OEM" jounce and rebound".Q:
Bump SteerA:
Change in toe angle under bump/droop. Normally, slight toe-in with bump is used in the rear and slight toe-out with bump is used in the front to aid stability. Excessive bump steer in the front can be caused from incorrect angle of the steering tie-rods from excessive lowering.Q:
Camber AngleA:
The wheel angle relative to ground/chassis in front/rear view. Negative camber is when the tops of the wheels are closer together than the bottoms. Tuning the amount of negative camber can be very useful in achieving maximum grip in racing. Excessive negative camber can wear the inside edge of the tires under acceleration or braking and reduces grip. Not enough negative camber can wear the outside edge of the tire while cornering and reduces grip.Q:
Caster AngleA:
The caster angle identifies the forward or backward slope of a line drawn through the upper and lower steering pivot points when viewed directly from the side of the vehicle. Caster is positive if the line angles towards the rear of the vehicle at the top, negative if the line angles towards the front. Positive caster improves directional stability.Q:
Center of Gravity (CoG)A:
The exact point around which an object, such as a vehicle, is perfectly balanced in every direction. It's the center point of the vehicles mass. The position of the center of gravity affects stability and handling: lower is usually more stable.Q:
Centrifugal ForceA:
The apparent force that draws a rotating body away from the center of rotation. Centrifugal force is not a true force; it is a form of inertia.Q:
Chapman StrutA:
Named after Colin Chapman of Lotus Racing. It is basically a MacPherson type strut used in a rear suspension.Q:
CoilA:
A term used to describe a type of spring.Q:
Coil BindA:
When a spring is compressed to a point that the coils make contact. The spring has travelled to its maximum compressed height or at full block.Q:
Coilover ShockA:
Coilover is short for "coil spring over shock". Consists of a shock absorber with a coil spring assembled together as one unit. Some coilovers (Eibach: Pro-Street-S) have adjustable ride height using an adjustable spring perch.Q:
Coil SpringA:
It's actually a torsion bar, wound into a helical shape. It's the Heart of the Suspension System carrying the car's weight under all static and dynamic conditions, absorbing the shocks from uneven roads and bumps, and correctly positioning all other suspension components. But it can provide only partial roll resistance as the Anti-Roll Bars (Eibach: Anti-Roll-Kit) provide additional support.Q:
CompressionA:
The displacement of sprung and unsprung masses in the suspension system in which the distance between the masses decreases from that at static condition. Compression damping is the primary factor in ride quality, road compliance and steering response.Q:
Control Arm (aka: A-arm)A:
A hinged suspension link between the chassis and strut or wheel hub. A Double A-Arm suspension has upper and lower control arms. A control arm may also attach to a spring, damper, anti-roll bar and pull/push rod.Q:
CorneringA:
The ability of a vehicle to travel through a curved track or highway. Cornering force (side force) is the lateral force that will push the vehicle toward the outside of the corner while cornering.Q:
Corner WeightingA:
Optimizing the weight of the vehicle at each wheel to maximize the vehicles transitional response. Tire traction and suspension movements are determined by the force (weight) on each corner of the vehicle. Equal diagonal weighting provides the best transitional response while equal front weight provides the best braking response. Adjustable ride height coilovers (Eibach Pro-Street-S) allow easy fine tuning for maximum and balanced cornering performance without adding ballast.Q:
Full Coil SuspensionA:
A vehicle suspension system in which all four wheels have their own coil spring.Q:
Damper (aka: shock absorber)A:
Shock/strut used to dampen the kinetic energy of a spring and control rate of load transfer. All hydraulic dampers (shock absorbers) work by the principle of converting movement into thermal energy (heat). For that purpose, fluid in the damper is forced to flow through restricted holes and valve systems, thus generating hydraulic resistance. See also shock absorber.Q:
Digressive DampingA:
Digressive damping describes a style of damper valving. Digressive means that as damper shaft speed increases, damping forces increase at a decreasing rate. In comparison, a linear rate damper follows the same increasing path. This allows for sport dampers (Eibach Pro-Damper) to offer more low speed control for performance handling without being overly harsh on rough roads or big bumps.Q:
Dive (aka nose-dive)A:
Vehicle pitch under braking.Q:
Double A-ArmA:
Independent suspension design with a short upper and long lower arm connecting chassis to suspension upright. Each arm is in the form of an A or V when viewed from above. Very common in racing; allows precise control of camber and roll center.Q:
Downforce (aka negative lift)A:
Downwards thrust created by the cars aerodynamics, typically through wings and spoilers. Additional downforce allows a car to corner faster by increasing the vertical force on the tires, which creates more grip.Q:
Double WishboneA:
(aka: double a-arm)Q:
Droop (aka rebound)A:
Amount of down travel of a suspension system. In racing, the terms 'bump and droop" are used together to define suspension travel; automotive engineers call it "jounce and rebound".Q:
Drop LinksA:
Attach anti-roll bar to suspension arms, upright or strut. The name comes from the typical configuration: a link drops down from the anti-roll bar to the lower suspension arm.Q:
Dynamic Weight DistributionA:
Weight distribution while driving under transient handling or aerodynamic forces.Q:
Gas-filled Shock Absorber (aka: gas shock or damper)A:
A shock that uses nitrogen gas, to pressurize the fluid in the shock to reduce or prevent aeration or foaming which can cause cavitation and loss of damping.Q:
GripA:
The amount of adhesion (traction)a tire has to the road.Q:
Heavy-Duty Shock AbsorberA:
Shock absorbers having reinforced seals, a mono-tube design to reduce heat build-up, and a rising rate valve for precise spring control.Q:
Helper SpringA:
A very soft spring used in racing to prevent the Main Spring (or Main- and Tender Spring) from becoming loose in the spring seats, when the suspension is unloaded or at full droop.Q:
InboardA:
1.Suspension spring system where the spring/damper is mounted near or within the chassis via rocker and pull/push rod system. Principal advantage is removing the spring/damper from the airstream, improving drag and downforce on ground effects cars (motorsport).Q:
Independent SuspensionA:
Any suspension which is not a solid axle type. This allows each wheel to move vertically (reacting to bumps or road irregularities) independently form each other.Q:
Instant CenterA:
The wheel and tire motion is constrained by the suspension links on the vehicle, the motion of the wheel package in the front view will scribe an imaginary arc with an "instantaneous center" of rotation at any given point along its path. The instant center for any wheel package can be found by following imaginary lines drawn through the suspension links to their intersection point.Q:
JackingA:
Vertical force applied on chassis under cornering. This force can lift the vehicle if the roll center is above ground or drop if underground. Susceptible with swing axle suspension design. Typically, jacking will cause a slight increase in ride height and slight loss of camber while cornering, which results in loss of grip.Q:
Jacking DownA:
Temporary lowering of chassis on bumpy roads due to excessive rebound damping.Q:
Jounce (aka bump)A:
The upward travel or compression of the spring and shock absorber.Q:
KinematicA:
Describes the motion characteristics of a suspension, as opposed to the force characteristics (motion ratios).Q:
Kinetic EnergyA:
The energy an object possesses due to motion.Q:
LiftA:
Opposite of downforce.Q:
LiftingA:
To raise a vehicles ride height for additional ground clearance to increase off-road capability. Eibach offers two types of fully engineered lifting:Q:
Linear-rate Coil SpringA:
A coil spring with equal spacing between the coils, one basic shape, and constant wire diameter having a constant deflection rate regardless of load.Q:
Lowering (aka suspension lowering)A:
Lowering the vehicles CoG. The main goal in lowering a vehicles CoG with the suspension is to improve handling and stability (street performance and motorsport). As always there is a right way and a wrong way to lower a vehicle.Q:
LooseA:
Aka oversteer (motorsport, NASCAR).Q:
MacPherson StrutA:
Type of car suspension system which uses the top of a telescopic damper as the upper steering pivot. It is widely used in the front suspension of modern vehicles and is named for Earle S. MacPherson, who developed the design.Q:
Mono-shockA:
Inboard suspension system which is actuated by both left and right wheels to a single spring/damper. All roll resistance is then carried by the antiroll bar. (motorsport - Formula series).Q:
Motion RatioA:
The difference of motion on a vehicles suspension spring and shock travel for a given amount of wheel travel. If the spring is half the distance from the control arm pivot as the wheel, the motion ratio relative to the wheel is 1 to 2.Q:
Multilink SuspensionA:
Common on independent suspension systems, using three or more lateral arms instead of only one upper and lower control arm per corner.Q:
NeutralA:
Handling characteristic between understeer and oversteer. This is usually the goal of chassis tuning, with a slight bias towards over or under-steer depending on track conditions and driver preference (motorsport).Q:
OffsetA:
Lateral distance between a wheel's vertical centerline and hub face. Positive offset has wheel center line further outboard than hub face; generally found on front wheel drive vehicles and newer rear wheel drive vehicles. Improper offset can negatively affect the handling of a vehicle.Q:
Outboard SuspensionA:
Traditional suspension system where the spring/damper is mounted directly between the chassis and lower/upper arm or upright.Q:
OverhangA:
The lengths of a vehicle, either front and rear, which extend beyond the wheelbase.
