Q: Will a shock absorber help towing a trailer or caravan?
A: A Koni shock will definitely assist in towing , because of the stiffer slow movement damping discussed earlier the rear of the car is far more stable and the weight of the towed item will not push the rear of the towing vehicle around as much.
Q: What’s the difference between a Koni and other brands of Shock.
A: KONI firstly design, develop, and manufacture their own products. This means every damper built by KONI is done so with the optimum performance in mind. Koni spend millions of Rands developing each part number to ensure it will give you the ultimate in Performance and comfort for each application. Cheaper brands use general valve settings and don’t spend the time and money to optimise performance because they don’t manufacture their own products. Semi brands (products made by one company and branded for sale by another company) will never have the ultimate control over the design because it’s not done in house, and often carried out by Companies who mass produce replacement shocks (cheaper less performance orientated parts).
The benefit of a KONI damper is its ability to be adjusted in the rebound motion, to optimise performance where spring strengths have been changed. The biggest advantage however is the fact that unlike a normal shock which gets stiffer the faster it moves in and out, a KONI has a flatter performance curve rather than a linear one. This means in layman’s terms that it is stiffer in slow shaft movements and softer in faster shaft movements. This is critically important and we will explain why.
When travelling at hi speed or, on smooth surfaces (motorways and A. class roads) the shock needs to be stiff when moving in and out slowly to give the car stability in hi speed cornering, swerving and harsh braking. Most shocks are too soft in this instance and the car is unstable and body rolls a lot. The KONI shock in hi speed shaft movements such as bad roads or dirt roads is softer than the standard shock and allows the vehicle to get more traction, more stability, and more comfort due to quicker reactions from the shock. These two simple facts already make the KONI shock the choice for discerning clients, whilst all the other benefits such as superior built quality, stronger mounting points, longevity, and cost just add to the value proposition from KONI.
Q: My retailer is telling me that a foam cell is better than a Gas?
A: The biggest marketing tool used in Shock absorber sales is the advertising of the Gas or Foam cell. Products like, Nitro charger, Gas Ryder, Foam cell technology and so on. These are all weak forms of advertising and simply show that the manufacturers don’t have any real advantage over its competitors. Firstly every shock containing Gas will have Nitrogen in side. Nitrogen does not form condensation when it’s hot like fresh air would so to protect the inside of the shock from Rust we always have Nitrogen inside. A foam cell simply replaces the Gas it is a small piece of foam that compresses as the shaft enters the shock body and allows the additional mass of the shaft. Sales comments like “Nitrogen impregnated” should be treated with the contempt they deserve, and totally ignored as any serious sales pitch. The bottom line here is buying the best you can afford; if it hasn’t got gas in it, it probably doesn’t need it so do not be concerned.
Q: which shock is the best Hi pressure gas or Dual tube
A: Whilst they both work well, generally the mono tube shock is more efficient in extensive use. Because the area the valve works in is air tight and completely full of oil under high pressure there can’t be any aeration whatsoever. There are some down sides to the Mono tube shock however, the high pressure gas makes them a little harsher on the ride and the construction means that any damage to the outer casing will cause the shock to fail. The floating valve and the main piston valve run directly on the outer tube and the surface of this must be perfect so they seal. If a dent appears in the side of the structure the valves cannot pass freely over the dents and the shock will not work, and will need to be replaced.
Q: My dealer is selling me Gas shocks, is it better than oil filled shock?
A: If the retailer makes a comment about Gas being better than oil, STOP listening to him immediately because it is clear they don’t understand shock absorbers at all, and will sell you any rubbish!!
Hydraulic dampers (shock absorbers) cannot function without oil!! Most well designed shocks can function without gas perfectly (excluding monotube type gas shocks). The design of the valve system is the heart of the shock and determines the overall performance. A common problem with shocks is aeration of the oil, this is when the shock is moving fast and the oil does not flow correctly through the valves and bubbles form in the oil. The bubbles will flow through the valve with little or no resistance and the damper forces will not be correct. The manufacturers put a small amount of Gas at approx. 6 to 7 bar in the shock to stop the aeration in the oil and optimise the performance.
Often the best designed shocks do not need gas as the control of the movement is done perfectly well without it. Bigger quantities of oil and larger valve diameters in the shock allow for this. A mono tube shock is quite different inside to a normal dual tube shock and in this instance gas is imperative to ensure the shock works correctly. In a dual tube shock the reservoir is the area between the inner and outer tubes, the oil level in this chamber rises and falls as the piston rod goes in and out.
In a mono tube shock the gas occupies the bottom third of the shock and the oil the other two thirds. Separated by a floating piston the oil and gas cant mix, as the piston rod pushes into the oil chamber the displacement of the shock shaft is taken up by the gas compressing in its chamber.
Q: If my vehicle is only loaded when I go away should I change springs to heavier duty?
There is a better way to give the vehicle loading capacity just when you need it. Air bags fitted to the rear springs can be inflated and deflated as and when you require it , This makes so much more sense and if used properly can be ultra-reliable. A trip to the Gas station can pump them up in minutes or, an on board pump and gauge can be used. These components are well priced and more comfortable when unloaded than an uprated spring.
Q: My dealer recommends I have to buy springs with my shocks?
A: It is true that the spring and shock work closely together and they are matched in what they do, However the shock absorber is a serviceable replacement part and the spring isn’t!
This means that in a standard scenario the shock which is supplied by the O E Manufacturer is required to be replaced regularly. If better performance is required the shocks should be replaced immediately you acquire the vehicle. The factories generally fit normal, non-performance cheaper shocks because not every purchaser requires the ultimate in shock performance; they are basically catering to the average client not the discerning, more demanding one.
There are some real reasons to change springs and we have touched on one of them earlier, the lifting of the vehicle? This can be done with spacers and this is a good way to keep the standard spring characteristics and comfort. Then some suppliers change springs, here a more heavy duty spring can affect comfort because it is harder. The other reason to change springs is if the static weight (permanent weight) of the vehicle is increased. The fitting of steel bull bars and winches add serious kilogrammes to the nose of the car and springs can be fitted to compensate this. In the same vain if roof top tents and roof racks fully loaded are left permanently springs can be replaced.
Q: What are the disadvantages of lifting my 4×4?
A: Unfortunately there are a lot more disadvantages than advantages and this is the mine field you play on when buying 4×4 Off Road suspension from none technical suppliers. The purchaser often non-technical themselves rely on sales people to sell them the correct parts for his car and listen to his needs and cater to them with the best of their ability. Because most of the market here in SA is dominated by components made or supplied from Australian companies who simply rebrand other manufacturers components, the hard core technical knowledge is simply not there. Just because someone can drive over land and over rocks does not make them a suspension expert at all, so beware. The customer is King and if you ask all the correct questions you will probably get the correct solution and not spend money unnecessarily. To answer the question however, the first thing to change is the centre of gravity of the car , this obviously lifts higher too, and the motor manufacturers spend a lot of time and energy to get the centre of gravity correct so a car out of control will spin around and not fall over ! When we lift the car up the likelihood of a roll over increases. The worse news is that as the car lifts up the independent suspension on most modern off road vehicles narrows the track width, the higher you go the narrower it gets.
Now the situation is even more dangerous as the centre of gravity is higher on a narrower platform, this will most definitely affect its cornering stability and potential to roll instead of spin round. You tube have very graphic scenes about testing of standard vehicles have a look at this and see just how bad the situation can be , Moose Test Fail Compilation. Safety standards in SA are not as stringent as in Europe so it is possible that many components available freely in SA would not be available in more safety conscious places in Europe. There is little we can do about this other than to educate potential customers about the workings of the vehicle and the effects the modifications we do to their cars will have. An informed customer will make the correct choices 99 % of the time.
Q: What are the advantages of lifting the car?
A, A slightly higher car will give a small amount of extra ground clearance in the centre of the vehicle when going over obstacles. Remember the transmission (Axles) cannot change as their height off the ground is dictated by the wheels! The suspension can be changed to lift the vehicle (springs or lift kits) and in some cases the body can also be lifted off the chassis to give more clearance in the wheel arches. Once you have extra clearance in the wheel arches the fitting of bigger wheels can be accommodated and this will increase the ground clearance of the axles and transmission. There is also the cosmetic side of the lift, many people enjoy the more butch look of an off road vehicle with bigger tyres, some of these vehicles never see a dirt road however!
Q: Why should I lift my 4×4 ?
A: The reality of this is quite simple you shouldn’t lift the car up unless you have a very specific need to. Most 4×4 suspension companies will revel in the idea, and sell you a very expensive complete suspension solution without actually asking you what you do with the vehicle and what your expectations are. 99% of the market use their 4 x4 off road once or twice a year, it is not justified to lift such a vehicle when its primary purpose is a daily commute. There are far more problems lifting a vehicle up than advantages, and the user of the car must understand what the down sides are so they can make the right decision and not waste money.
Q: My off road vehicle is uncomfortable?
A: Quite a common problem that stems from the design of the suspension! An off road vehicle generally has high unsprung mass IE. Big wheels, and heavy transmission components to enable it to do what it does off road. Therefore it will never ride like a car and you won’t get it to either. There are things you can do to optimise the comfort however and generally this involves fitting of a high performance better designed shock absorber.
Q: What are the differences between air suspension and conventional systems
A: The main difference is that the Metal coil spring is replaced with an air bag. The air is pumped into the bag by an on board pump and the differing pressure in the bag will lift or lower the car ride height. Generally fitted at factory level to larger more comfortable cars with no performance expectation but comfort as the major goal. Sometimes used to keep the car level by sensing control arm angles and switching on a pump to maintain the rear levelling of a car when it’s loaded. It is often used in show cars where the car needs to be lowered to excessive positions temporarily. These kits are not designed to be used at hi speeds as a failure on an air bag could be fatal.
Q: What is Bump steer?
A: Bump steer is often caused by a car that has been lowered too far and the steering rack and tie rods are not parallel to the ground (or control arms) anymore. Because the tie rod arches from the steering rack the lower the car is the more the two front wheels will try and point in different directions. This can of course be corrected with wheel alignment BUT with acute tie rod angles the toe settings of the car will continually change when hitting bumps and cause torque steer and unusual tyre wear.
Q: Why does the fitting of bigger wheels affect my comfort?
A: The major factor to consider is that the Shock absorber controls the unsprung mass of the car and this of course includes the wheel. When fitting a larger heavier wheel the standard shock cannot cope as well in controlling the movement of the unsprung mass. Also the smaller side wall on a low profile tyre is less capable of absorbing the impact of a bump on the road than a larger side wall.
Q: Since I lowered my car the tyres touch?
A: This is a common problem, BUT it isn’t the suspensions fault. If you fit a tyre / wheel combination that is bigger than the original you will have problems. It is imperative that the overall size of the new wheels is exactly the same as the original; it can be wider of course as long as it does not touch the inside or outside of the fender. If a wheel retailer sells you a wheel with the incorrect offset you will have problems. If the wheel is bigger in diameter the performance of the car will worsen and the fuel consumption will increase. The speedo will be inaccurate and all these are negative factors generally in the performance of the car.
Q: What is damping adjustability?
A: The adjustability of a shock absorber has distinct advantages, specifically for track days and drag racing. Various disciplines of motor sport require different performance from a shock absorber. Adjusting the shock absorber will make the stiffness greater or less, and this can often be done in the rebound motion. (Shocks sometimes have a single adjustment for Bump and rebound or independent adjustment of the two) Stiffer shocks can make a car much quicker around a track and improve standing starts in a drag race. All manufacturers of hi performance dampers have realised the importance of adjustability and any manufacturer not offering this as an option has completely missed the boat .
Q: Why do quality Coil over kits cost so much?
A: A suspension kit, sport or coil over must be designed and built specifically for the car it is fitted to. The characteristics of the valving are specific for the model of car it is fitted to. Cheap coil over kits are not model specific and one damper design can be applied to 20 different cars all of which have differing characteristics, this keeps the cost of kits down. It is also one of the reasons they ride poorly and generally hard. One way to know if a damper kit is not model specific for the application is if the kit comes with a camber plate at the top and screw off bottom brackets. The easiest way to get one shock to fit many cars is to supply a camber plate to adapt one top pin design to fit many cars shock mounting points. Please also be aware that Rose jointed camber plates are noisy. Generally these noises are excluded from the warranty as manufacturers know they will never be able to stop this noise. Also as the bearings wear, the noise gets worse! Expensive coil over kits are model specific and custom designed exactly for the application and this is why they are expensive, they will never come with camber plates as the use of the original mounting is the most desirable way to do it.
Q: I want my car to have a certain look , can I achieve this ?
A: Yes it is possible but, remember the suspension on the car was designed in a way to make the car safe and handle well. Some changes to this set up will cause the car to handle worse and should be considered carefully before doing. Custom heights can really only be achieved with a Height adjustable suspension kit as most quality sport springs are designed to enhance handling not impair it.
Q: Can I cut the springs to get a cheap low stance
A: NO! This is as dangerous as heating the spring, although it doesn’t get softer it will not be long enough to stay in place in the spring seats when the car is lifted from the ground for service.
Q: Can I shrink the standard springs to get the appearance I need without spending the money on new springs?
A: NO! This is really dangerous to do and the lack of safety checks and workmanship standards in SA allow it happen. The spring works that carry out such work should be stopped, or closed down. The action of warming a spring up to shorten it will not only soften the design of the spring but also make it too short to stay tight in its spring seats if the car is lifted from the ground for maintenance. To warm a car spring with an Oxyacetylene torch is even more dangerous as the spring will break at the point of the heat application. The spring cannot fit properly in its seats again as it distorts badly during this dangerous process.
Q: How do I know if my shock absorbers are ok?
A: There really is only 1 way to test a shock absorber, remove it from the car place it in a shock dyno and measure it against the original manufacturer spec. there are several problems with this , 1 costly to remove the shocks , 2, the machines are really expensive . 3, without the original spec you cannot be sure how far off the shock is from its original design spec. Many tyre fitment centres have gimmicky machines which rock the car and measure the shocks ability to resist movement. The problem here is the results are blurred by the shock mountings (rubber) and the tyre pressures (also rubber and can vary from one manufacturer to another) Tyre pressures which also differ can also taint the results which are then used to convince you do replace the shocks. The simplest rule of thumb is this; if the shock is leaking it may well still be ok for a short while but will ultimately fail. If the shock has done over 100k kilometres it most definitely isn’t performing as well as is it was intended. Shock oil works at similar temperatures to the engine oil in extreme cases and the oil most certainly will have thinned much like your engine oil when you drain it. Therefore how do you know if the shock is finished, leaking or distance travelled?
Q: I have purchased a lowering kit and my car rides very poorly?
A: There are a few reasons for this and the most common reason is the standard shocks fitted to the car. If they are old or worn out the car will definitely ride poorly as the shock absorber cannot control the bumps fast enough. Often the shocks fitted are inferior quality and simply cannot deal with the lack of travel the sport spring offers. The other reasons are the bump stops; many cars have long standard soft bump stops. These might need to be replaced by a smaller (shorter) hi performance bump stops. The last reason is that you lowered the car too much and the car is permanently riding on the bump stops, this is really not good for handling, safety, and comfort.
Q: I have purchased a spring kit and my car seems to be getting lower and lower over time?
A: Springs are a non-serviceable item on the car and should never be replaced. The fitting of poor quality springs however can cause the symptom of height changes. Poor design or poor quality of material to make the spring can cause the deterioration in height. Please note if a supplier of a sport spring tells you the car will settle after fitment, they have sold you inferior parts as quality springs will stay the same as the day they are fitted, forever.
Q: How will the ride be if I fit a lowering sport spring?
A: The lowering of a car actually removes valuable movement from the suspension so naturally the car will bottom out sooner than it would at standard height. The factors to worry about are what condition are the standard shock absorbers? How low is the car to be? What length and what material are the bump stops made of? If shocks are standard, and or worn the ride will not be perfect!
Q: Will the sport spring work with my standard shocks?
A: The quality sport springs that are T U V approved will fit with standard shocks and they are designed to be a dual rate design so that they do maintain pressure on the upper and lower spring seats even when the car is lifted from the ground by a service lift. The new lowering spring could be as long as the original standard spring but due to the dual rate coiling of the spring it will sit lower once the car is on all 4 wheels.
Q: How low can I go?
A: 30 to 40 mm is the maximum you can lower a car safely, many things go wrong when a car is lowered more than this. Drive shafts, shocks and shock mounts; steering components all take serious strain and will fail prematurely. Operational problems with the car like Bump steer can cause excessive tyre wear on the steering tyres. Excessive camber can also cause excessive tyre wear and drive shaft issues.
Q: Why should I fit a sport Shock absorber?
A: A lowered car has less travel on the suspension, and therefore the shock needs to be stiffer to react quicker when the car hits bumps in the road, a bottoming out shock absorber is really not good and can cause loss of control of the car in extreme cases. A stiffer shock absorber gives a better ride and maintains more control over the standard shocks. The problem with just making a shock stiffer is that on bumpy roads the ride gets unbearable, so it is important to fit a superior designed shock that has a flat response graph rather than a linear one. This means the shock must get softer the faster it moves in and out, and not harder the faster it moves.
Q: Why do we fit lowering springs?
A: The most common reason is to make the cars appearance better. Many spring manufacturers will advertise the fact their sport spring makes a car handle better! This is strictly not true as a car lowered with springs and standard shocks, will often handle worse due to the standard shock absorbers being too soft and bottoming out during harsh cornering. The relationship between the shock and spring is of paramount importance and fitting sport springs and no sport shocks is definitely not the ultimate set up. A sport spring is approx. 20 % stiffer than a standard spring and once again needs a shock matched to this for the ultimate performance.
Q: Why is the shock absorber so important?
A: The shock absorber is designed to turn Kinetic energy ( Movement ) into heat , in other words it absorbs movement of the suspension, and controls the otherwise uncontrollable oscillation of the spring to make the vehicle stable and safe. The resulting heat is dissipated through the body of the shock to atmosphere.
Q: Shock absorbers are they important ?
A: Shock absorbers along with the brakes are the two most safety critical components on the car!!