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# Suspension Tuning

Suspension Tuning is a critical part of getting the ultimate performance package, it is even possible to have a more competitive car then a rival with superior upgrades, by having a well balanced set up. It all comes done to extracting the best from what components you have and making sure they are well set up for the road or track conditions.

## Camber Angle

 The Camber angle settings of the suspension can come in three different variations (vertically viewed from the front of the car), Positive, Neutral and Negative Camber. It is normally represented in degrees.While it is true that a car's suspension will most likely pass through various degrees of all of them in the normal operation of the vehicle (depending on set up and design), having a good base in the beginning will be vital in having a competitive package for a given goal.Negative Camber: increases the cornering grip of the tyre/ tire during cornering, helping to maximise grip and providing  better traction. Too much Negative Camber will increase the  inside tyres/tires wear and could result in handling imbalances.Neutral  Camber: best suited for maximum acceleration and braking, this set up makes sure a flat contact patch is retained on flat road surfaces. The inside wheels may lift on the inner contact edge of the tyre/ tire duration extreme cornering.Positive Camber: used more for off road applications, especially with agricultural vehicles as this setting helps the wheels to turn with lighter steering effort required.The outside wheel under extreme cornering loads will benefit, but camber levels are normally linked ( might be a consideration for oval tracks).While double wishbone suspension is normally designed for camber angle adjustment, macpherson suspension might require aftermarket suspension mounts with various slots for adjustments.

## Caster Angle

 The Caster angle is the ability of the front suspension system to self center under cornering loads. Too much caster and the front of the car will understeer more ( positive caster), too little and you will get oversteer handling characteristics (negative caster).Improper adjustment will result in steering inputs required both into and out of a corners, resulting in a car which is difficult to keep on a straight line.  A large positive camber setting (wheel facing forward of axis) is good for high speed stability but can make it more difficult for turning the steering, excessive amounts will increase tyre/tire wear.

## Ride Height

 Depending on the exact road or racing environment, generally speaking the suspension should be as low as possible to the floor with out the the car bottoming out ( wheel, chassis or ground making contact with each other).There are good reasons for reducing the ride height:Lower center of gravity-reducing weight transfer levels and aiding handling characteristics on the limit.Increased aerodynamic downforce, the front should always be slightly lower then the rear to gain a rake effect (reducing lift) to aid downforce.Reducing drag and increasing fuel economy.Adjustments will require fitting of adjustable coilovers, dampers, or shorter springs. Care must be taken in lowering the car as it has a diverse effect on other suspension geometry and this could end up hindering the performance potential.

## Spring Rate and Wheel Rate

 Spring Rate:It is a ratio indicating the resistance of a spring during bump or rebound (compression or expansion).Also known as suspension rate, it is critical for setting the correct ride height and is proportionate to the movement of the length of component travel in its stoke phases. As we know the whole job of suspension is to keep the wheels and tyres in contact with the ground at all times, for total performance.By having the ability to change the spring rate, heavier vehicles can have a higher setting to stop the suspension bottoming out under extreme loads, or if the car has big downforce generation abilities. Softer spring rates could be an advantage in rougher terrains or raised kerbs at apexes. If have seen a car jump of a kerb at speed, than lower spring rates are needed. Unless of course you enjoy bouncing down the track, or even off the track in worse case examples.Sometimes people complain when driving sports or track focused cars with competitive suspension on normal roads, this is because of higher spring rates.Most springs will have ratings on after market upgrades and unless you have radically reduced weight of the car or revised the aerodynamic package, it is best to keep to the manufactures' recommendations. Spring rates can be measure on a machine or alternative the following formula may help:$k = \frac{d^4G}{8ND^3} \,$where d is the wire diameter, G is the spring's Shear Modulus (for example about 12,000,000 lbf/in2 or 80 GPa for steel), and N is the number of wraps and D is the diameter of the coil.Wheel Rate: Similar to spring rate but measured at the wheel instead of at the suspension linkage of the spring. Also it is important to know that the wheel rate would always normally be less than the spring rate, as the wheel will travel a larger distance through compression or expanding than the spring.Wheel Rate is the Motion Ratio squared times the Spring Rate:Wheel Rate = Spring Rate * (Motion Ratio ^ 2) * Spring Angle Correction

## Toe In/ Toe Out

 Toe In or Toe out is another important suspension setting, it affects the handling of the car in terms of tyre/ tire wear, straight line and cornering characteristics.In terms of the best braking and acceleration capacity for the tyres/ tires, it is best to have neutral toe settings.Too much toe in causes the outsides of the tyres/ tires to wear out.Too much toe out causes the insides of the tyres/ tires to wear out.