Shocks & Springs: Tech, Buyer Guide & Brand List

Hi everyone!

This is a guide for newcomers and others with little understanding of shocks and springs.

Suspension is a fundamental way of improving the looks and/or performance of your car. Compared to coilovers, shocks and springs are a real pain to the uninitiated as they're not a complete set; therefore getting the right combination is a problem. Shocks offer a limited range of adjustment in comparison to coilovers. However, a well chosen and set up "Shock & Spring" combo will outperform low-end coilovers while providing better comfort. To help members understand and find the right combination for them, this thread will go through shock and spring basics, technical details, buyer guide and a list of brands.

Disclaimer: This is a basic guide that presents information in its simplest form possible and therefore may NOT be entirely accurate.


Shocks & Springs: Basics


Shocks: Definition

Shock absorbers or dampers are a piston rod device that dampens spring movement. In doing so they improve ride quality, comfort and performance.


Springs: Definition

Springs are metal coils with elastic properties that absorb the motion of the wheels by compressing and rebounding.

Shocks: Basic & Advanced

Shocks: Basic

Shock Features

Here is a diagram with three types of shocks you will find on the market. They have a lot of components but we'll focus on the main ones.

http://img194.imageshack.us/img194/8...berdiagram.png
Credits - Koni

Features

Work in Progress

Shocks: Advanced

Shock Features

• Damper Type - There are two types of dampers:
  
  
  • Twin-tube - Hydraulic & Low Pressure Gas - [LHS of Pic]
    
    
    • Construct - Twin-tube refers to a shock absorber that contains two cylinders: inner and outer. The piston valve that displaces the fluid is located in the inner cylinder.
      
      
    • Advantages
      
      • Suspension Stroke - Twin-tube stroke length is along the entire body of the shock absorber, whilst the monotube's is shorter because the oil and gas chambers are stacked on top of each other.
        
      • Comfort [Due to gas] - Using low pressure gas allows twin-tubes to absorb shock better, resulting in greater comfort.
        
      • Durability [Due to gas] - Low pressure gas also means less pressure is forced against the seal so there is less friction, which allows it to last longer.
        
      • Cost - Twin-tubes are invariably cheaper to make than monotubes because of their components, design and manufacturing process
      
      
    • Disadvantages
      
      • Lack of fluid capacity - As the twin chambers take up more space inside the shell casing, twin-tubes contain less fluid than monotubes, reducing their ability to maintain consistent performance for long durations.
        
      • No Precision Dampening [Due to gas] - The twin chamber design means a smaller piston is required; therefore a twin-tube typically can not provide as precise dampening as a monotube.
        
      • Aeration [Due to gas] - The entire unit is under high stress because both the fluid and gas chambers are not separated. The combination of the rapidly moving piston, fluid and valve creates friction. If the fluid is forced through the value at a sufficiently high speed, this forms air bubbles in the fluid behind the piston, which is called aeration. This can lead to foaming that results in the shock absorber not dampening properly.
      
      
    • Suitable Application - Street (and Track for high quality twin-tubes)
    
    
  • Monotube/Inverted Monotube - [RHS of Pic]
    
    
    • Construct - Unlike the twin-tube, all of the shell casing's interior acts as the cylinder.
      
      
    • Advantages
      
      • Consistent level of dampening - The monotube design has a greater fluid capacity, allowing for increased heat dissipation and therefore more consistent performance.
      • Precision Dampening - Monotubes can run a larger piston due to their single cylinder design. This allows for a wider distribution of pressure that enhances the shock's precision.
      • No Aeration - Both the fluid and gas are completely separate so there is no aeration to hinder dampening consistency.
      
      
    • Disadvantages
      
      • Lack of Stroke/Bottom Out - As the oil and gas chambers are placed on top of each other, a monotube typically has issues with maintaining sufficient stroke. This makes it more prone to bottoming out.
      • Stiffness [Due to gas] - Monotubes by nature require high pressure gas in the gas chamber. This impairs shock absorption ability, making them comparatively stiffer than twin-tubes.
      • Durability [Due to gas] - As mentioned above, the requiring high pressure gas also leads to accelerated seal wear, thus causing increased internal friction that leads to premature failure.
      • Durability [Due to inverted design] - Unique to inverted monotubes, their complex design and additional moving parts means more things can fail.
      • Damage Resistance - The internals of the shock absorber are placed very close to the shell casing; so if the shell casing is damaged, it will also damage the internals.
      
      
    • Suitable Application - Circuit and Street [High quality coilovers can provide sufficient dampening and stroke]

Springs: Advanced



Spring Features


Standard Springs
http://performance-suspension.eibach...ings_lrgth.jpg
Credits - Eibach

Progressive Springs
http://www.spoonsportseurope.net/med...-001_2_1_1.jpg
Credits - Spoon Sports

Shocks & Springs: Buyer's Guide



Where to start?

• What am I after - Make sure you know what you want, be it just a simple drop, a drop and some performance, drop/performance/comfort or whatever combination, otherwise you will end up running something that you will dislike and make the car a pain to drive. Remember that we mod our cars because we want to enjoy them.
  
  
• Application - Similar to the above, application is also everything. After all, there is no point running super stiff circuit valved coilovers on a car that will only see the street and driven mainly on broken tarmac. That's just a recipe for disaster not only in performance, but to your own safety.
  
  
• Budget - Another important point is the amount of money you feel justified to spend. If your budget doesn't allow for the dream setup, you must look for a compromise.

What to look for?

• Damper Type - Twin-tube or monotube? In a perfect world, twin-tube would be used for street and monotube for track. It's not that simple however; a high quality monotube will almost be on par in comfort as that of twin-tubes and will almost last as long. Conversely, a low quality monotube is horrible for street and tends to wear out very quickly, so it will feel like it's not absorbing the bumps at all.
  
  For cars that are used as a daily, a twin-tube or high quality monotube will give you performance and comfort.
  
  For cars that are used on the track more often than the street, a low or high quality twin-tube/monotube coilover is suitable; budget and performance goals will determine which one you would go for.
  
  
• Damper Valving - Digressive is often regarded as the best damper valving and for good reason. They have a good feel at low piston speed whilst giving a softened response at high piston speed speed, minimising harshness and providing control. Digressive shocks however are some of the most expensive on the market.
  
  Shocks are more difficult to to judge quailty as they usually don't release much information compared to Coilovers. In general the category of the shocks will infer much of its characteristics. You can generally separate them into 4 categories. The 4 categories are OEM/OEM Replacement, Sport, High Performance and Competition/Racing.
  
  
  1. OEM/OEM Replacement Shocks - Best matched with stock or springs that offer slightly stiffer rates and slightly lower ride height.
     
     Examples -
     
     
  2. Sport & High Performance Shocks - Sport & High Performance are usually shocks that are designed to handle stiffer and lower springs. Sport Shocks are usually Non-Adjustable and can handle mild - moderate springs. High Performance shocks are usually Adjustable and can handle any spring short of Competition springs.
     
     N.B.Some shocks are somewhere between the 2 categories, it is usually decided by personal preference.
     
     Examples [Sport] - Koni STR, Koni FSD Shocks, KYB AGX Shocks
     Examples [High Performance] - Koni Sport/Yellow Shocks
     
     
  3. Competition/Racing - For the serious racers, just like coilovers they will have many adjustments [2-Way, 3-Way, 4-Way] along with external canisters.
     
     Examples - Koni 28XX Series Shocks
     
     
     
  4. Spring Rate
     
     1. Think about what you want most: comfort or performance.
     2. Research your car's weight. In general, heavier cars require stiffer springs to counteract the car's mass for the same effect that a lighter car with softer springs so base it in respect to chassis not spring rates alone.
     3. Research your car's suspension layout and factory rating. This is very important as different layouts will require different approaches to suspension selection and tuning.
     4. Research what is available in the market for your car.
     5. Compare the spring rate of the coilover you're considering to your factory spring rate, this way you can infer how much stiffer it's going to be.
     6. Check the shocks's damper valving/quality if possible. The stiffer the spring rate is, the better the damper's valving should be to compensate for the stronger springs.
     7. Choose the right one for you; refer back to the first point - softer for comfort, stiffer for performance. Additionally if the roads you drive on most are **** then it's not smart to run super stiff springs; instead go softer than normal. If the roads you run on are smoother, you can afford to run stiffer springs if you want more performance, otherwise stick with the norm and you'll be fine.
     
     
     
  5. Damper Adjustment - Shocks unlike Coilovers usually feature limited number of 'steps' available to tune. Most Sport/Performance dampers usually feature 4-5 steps of adjustment with each step having a definitive difference to.
     
  6. Damper Quality - This is very hard to assess when you can't necessarily try and by. Fortunately there are a few key features, which can help differentiate a superior shocks from an inferior one.

Work in Progress

Shocks & Springs: Compatibility & Reference Guide


Shocks & Springs: Compatibility Guide



Shocks & Springs: Reference Guide


Coming Soon!

Shocks & Springs: Initial Setup



Height Adjustment




Damper Adjustment - Street

There are many ways of setting up dampers but here is a general, easy way of doing it. The assumption is that you haven't done this before, but once you have a few times, you will roughly know how to offset the front and rear damper settings.

N.B. The lower your car is, generally the stiffer you need to run the dampers to ensure the coilovers can sufficiently keep the car sprung, otherwise the car will bottom out.

• General Idea - For a street car, the safest way to increase handling performance is to ensure the tires are always kept in contact with the road under all circumstances. This is achieved by not running the stiffest setting (although this depends on the coilovers).
  
  
• Before Starting - After installation is complete, go get the wheel aligned.
  
  
• Starting - Start off by having the dampers set halfway for both front and back. Go for a drive on a route you know well, ideally with a mixture of smooth and rough surfaces to feel how the car reacts and also the damper's behaviour at different speeds.
  
  
• Tuning Procedure - Go for a test run each time you adjust a few clicks left or right then adjust accordingly. A 'few' means proportionate to the maximum amount of clicks. For example, let's say 10 clicks is the maximum. You initially set [F] 5 | [R] 5 and drive on your test route. You find it was too soft at the front and just a fraction too stiff at the rear, so you'd then try [F] 7 | [R] 4 and repeat the same route while noting the differences on different surfaces and at different speeds.
  
  
  • Tuning #1A - Front - Ideally the front dampers should be stiff enough to allow you to feel the road better but not so stiff that the nose bobs up and down, which causes the tyres to lose contact with the road and loss of steering feel.
    
    
    • Too Soft - A damper setting can be too soft when either the steering feel is too 'loose/gentle', lost altogether/when the car floats around like a boat.
      
    • Too Stiff - You will know it's too stiff when the nose of the car is too sensitive to changes in road condition, i.e. over bumps or reacting too harshly and exerts excessive force on the driver. It is also too stiff if it feels like riding a horse in general.
    
    
  • Tuning #1B - Rear - Ideally the rear dampers should be stiff enough to allow you to feel the rear following the front, but not so stiff that it feels nervous; especially during hard braking.
    
    
    • Too Soft - A damper setting can be too soft when either the rear of the car is not communicating to you as the driver or if it's not tracking the front correctly. Same as front dampers, it will also float around like a boat when too soft.
      
    • Too Stiff - A rear that is too stiff can usually be felt during hard braking, especially over bad road surfaces. If the rear tires don't feel like they're in contact with the road (a sensation like the rear is skipping or bouncing), you know you have to soften the rear dampers. As with the front, the rear will feel like riding a horse and obviously this is bad for your rear passengers.
    
    
    
  • Re-tune - You keep repeating this process until you attain or have nearly attained a desirable result. It is almost impossible to get the perfect setup unless both your car and coilovers are that good. In most cases you'll need to compromise.

Damper Adjustment - Track

• General Idea - For a track car, it's all about getting the sharpest feel to allow the driver to hit those apexes. Although there is little compromise taken, there are still some key points that need to be addressed.
  
  
• Car Spec - This may seem awfully strange, but the spec of your car will determine a lot of your setup. Differences in tires (Street ---> Semi-Slicks), chassis rigidity, driver preference, etc. all result in different setups.
  
  N.B. While going from street tires to semi-slicks provides a lot more grip, it also can introduce understeer. To counteract this, dampers, swaybar and suspension geometry should be altered to take full advantage of the semi-slicks' potential.
  
  
• Research the Track - Contrary to general opinion, not all circuits are smooth, especially older circuits. Some have not been resurfaced and along with undulated/off camber surfaces, this can have an impact on the setup so be sure to know what you're running on.

Work in Progress

Shocks & Springs: List of Brands


JDM


USDM/CDM


EDM



TDM - Taiwanese


Coming Soon!

excellent.

Haven't started yet LOL

subscribed

Ohh this is going to be interesting!

Definetly Subbed , I know you have not started yet but i am really looking forward to the material your working on.

Thanks Angel.