Of course we could write a whole essay about what suspension is, how it was developed, all the different types, and their pro’s and con’s. BUT in this article will will just cover the basics of what suspension is, solely concentrate on the types of suspension fitted to our cars, and how we can make it work to the best of its ability!
– So what is it and what is its purpose?
The suspension system fitted to a car normally consists of some form of spring, which the car is sat on, and a shock absorber. The basic purpose of suspension on an everyday car is to create a link between the cars body and the road, which absorbs the imperfections in the road surface to give a smooth ride. Without suspension the wheels would be mounted solidly to the chassis of the car. This would mean that whenever a car hit a bump in the road the whole car would be pushed up into the air, forcing the tyres to loose contact with the tarmac.
Now this is where things can start to get complicated. There is no “perfect” suspension, as different uses require the suspension to act in completely different manners. For example a super comfortable luxury limo will have very plush suspension which will absorb all the bumps in the road giving the car a super smooth ride, however such a car is prone to dive and squat during braking and acceleration and tends to experience body sway or roll during cornering. On the other side of the scale you have tightly sprung cars such as race cars which have much stiff suspension which on smooth race tracks allows the car to corner at incredibly high speeds with little body roll and high grip levels. But if you drove this car on the road you would have a very bumpy and uncomfortable ride as the car skipped and bounced over all the bumps and pot holes! So as you can see your cars required suspension depends entirely on your wants and needs of the car itself.
Our cars come with independent macpherson struts on the front. Being independent means that each front wheel acts independently from one another. The rear suspension setup depends on your exact model. The FWD cars come with a dependant rear beam and the AWD cars come with independent multi-link setup. The most important thing to take from all this is that our cars use coil springs and dampers both front and rear.
– What do the springs and shock absorbers do?
The purpose of the spring is to suspend the car from the floor. It serves to support any additional weight without excess sagging, and is also what determines the cars ride height.
Springs are very good at absorbing energy. When the car hits a bump the spring compressors absorb the upward motion. The issue with only having a spring is that they are not very good at dissipating energy.
After compressing, a spring will extend and release the energy it absorbs from a bump at an uncontrolled rate. The spring will continue to bounce at its natural frequency until all of the energy originally put into it is used up. A suspension built on springs alone would make for an extremely bouncy ride and, depending on the terrain, an uncontrollable car. This is why we need to incorporate a shock absorber into the design.
The shock absorbers job is to control unwanted spring motion through a process known as dampening. Shock absorbers slow down and reduce the “bounce” of the spring. They do this by turning the kinetic energy of the spring into heat energy which is dissipated through the hydraulic oil within the shock. The internals of a shock absorber are quite complex, but in simple terms it is essentially a piston which, when extended or compressed, forces oil through different sized valves and orifices, which in turn controls the speed of which the piston is allowed to travel.
Modern shocks are velocity sensitive. So the faster they compress or extend the more resistance the shock provides. This means that the shock can allow for slow dips yet also control fast brake dive etc. Some shocks are adjustable. This normally adjusts how much the valves inside are open and therefore how much resistance the shock offers. So taking all of this into consideration, it is obviously vital that the spring and the shock are matched correctly to give the correct amount of dampening.
SO moving on. I’m sure (seeing as you are on this site) like me you are primarily wanting your car to handle well at speed whether it be on the road or on the race track. So we will be focusing on how to best set our cars up!
What are my options in regards to upgrading?
There are several different options to choose from when you are looking to upgrade your suspension system. All of which can be found below:
– Lowering springs
Lowering springs are the budget suspension upgrade. It is also questionable whether or not they actually give any benefit to performance as will be explained below.
Lowering springs are exactly as the name implies. They are a spring which is shorter than the standard spring which drop the car by a set amount, for example 30 or 40mm. They are advertised as offering an increase in performance due to being slightly stiffer than standard and the car having a lower centre of gravity. BUT in reality, due to the car still running standard (and often old) shock absorbers, it means that the shock can not absorb the energy fast enough which results in a bouncy ride. This is also known as being “under dampened”.
If you decide to fit lowering springs we advise that you go with some from a well known brand such as eibach, koni, h&r etc.
– Shock and spring kit
A shock and spring kit is exactly as the name entails (again). It is a kit which consists of both an uprated lowering spring and also an uprated shock absorber which has been designed with the correct dampening to suit the spring rate of the accompanying spring.
Shock and springs kits are a good option for those who just want the car to be a little bit lower with improved handling, but still want the car to give a comfortable ride. They are mid range in terms of cost with a good branded kit costing from around £400.
If you decide to go for a shock and spring kit we recommend going for a decent brand such as Weitec, H&R, Blistein, Koni etc. Try to avoid cheap unbranded ebay kits.
– Coilovers
Coilovers are a type of suspension which come as a complete unit where the spring is over the shock and secured in place (sometimes rears are still a separate spring and shock). They are also the only type of coil suspension which has adjustable height, so the ride height of the car can be changed to suit either personal taste or to maximise performance. Higher quality coilovers also have adjustable dampening which can be adjusted to alter the balance of the car (we will come into that in a minute).
Coilovers are the best option in regards to performance. They often have higher spring rates (harder springs) than the other types of suspension mentioned above. They also offer more comprehensive and quality dampening.
There is a wide range of coilovers available, these can vary from low range budget options to top-of-the-range touring car spec units. There are cheaper options out there like JOM, FK, prosport and stance + which are around the £150-£250 mark. In terms of quality and performance they are quite poor so if that is what you’re after we would recommend to avoid them at all costs. But for people who just want to lower the car as much as possible for aesthetics they work fine.
If performance is what you’re after you will need to spend a little more. We recommend spending a minimum of £400-£500 which will get you a low end budget, but decent, set of coilovers such as the AP units.
We personally recommend spending even more, if you can, on other brands. Our favourite being Gaz golds. We also recommend kw, Blistein, weitec etc. these will cost between £600 and £1200+
Gaz golds can be bought from here.
Bespoke FWD rear coilovers
As you can see in the following images we have experimented in making some custom rear spring-over-shock coilover instead of using the typical separate spring and shock combination. This was done by getting custom Gaz golds made to our own spec, then fabricating some custom solid top mounts which bolt to the normal shock mounting location. There are a few benefits to doing this. Firstly it gives you more options on spring rates and lengths. It also allows more droop without the spring becoming dislodged. Additionally it opens up the option to use the original spring seat location to triangulate the rear beam, and finally it ditches the soft OEM rubber top mount.
Spring rates?
What do we mean by spring rates? Well in basic terms is is how hard the spring is to compress. The higher the spring rate the harder the spring.
A higher spring rate will reduce body roll, giving a lot more high speed cornering capabilities, and more control under sudden changes of direction. BUT it also increase the stiffness of the ride which means reduced comfort.
Specific spring rates only really come into play when you are looking at high performance coilovers which are going to be used on the racetrack. This is because most ‘off the shelf’ coilovers (even the ones classed as high performance) have spring rates which are too low for out and out track use. Buying coilovers, such as the Gaz golds, allows you to choose whatever spring rate you like and the shock will come with the correct dampening setting to suit. The spring rates that you choose will vary a fair amount depending on what you want from the car and the rest of the chassis setup. For example if driving on the track and running slicks you will want higher spring rates than a general road car due to the harder cornering and braking made possible from the extra grip.
We don’t currently want to give out conclusive figures, as depending on what tyres you use, roll bars, and handling preference, the preffered rates can vary quite a bit. However, upon our testing, using different size slicks on the track, we have found on FWD cars somewhere between 550lbs and 650lbs springs all round to be really effective. Although we are still yet to experiment with even higher rates.
These rates may differ a lot on AWD cars.
Dampening adjustment
Proper dampening adustment is a bit of an art-form. So we suggest if you want to dive into it’s deep realms you do plenty of research. But for now we are just going to go over the basics.
The bump and rebound need to be set at a point which is high enough to give stability, control body roll, and dissipate the kinetic energy in the spring so to reduce “bounciness” but be low enough as to not reduce overall grip or cause the car to skip over bumps. Therefore not loosing contact between the wheel and the tarmac.
As a general rule of thumb on the front of the car, the higher the bump and rebound adjustment the more prone to understeer the car will become. The lower the bump and rebound the more prone to oversteer the car will.
Whilst on the rear of the car the higher the bump and rebound adjustment the more prone to oversteer the car will be, and the lower the bump and rebound adjustment the more prone to understeer the car will be.
We have put this into a chart below to make it a little more simple to understand.
| Bump/rebound Setting: | Effect: |
| Front Increase. | More Understeer. |
| Front Decrease | More Oversteer. |
| Rear Increase. | More Oversteer. |
| Rear Decrease. | More Understeer. |
Anti roll bars
What are they and how do they work?
Anti roll bars (ARB) are a device which have the sole purpose of reducing body roll of the vehicle they are fitted to. The are essentially a steel bar, or tube, which connects the suspension on one side of the car to the other side so that as the suspension rises or falls the ARB is physically forced to bend so it creates resistance against the movement. Thus reducing body roll. What this also means is that the inside wheel is actually being lifted off of the floor which can reduce overall grip.
The basic principles behind how an ARB works is that the thicker the bar is the stiffer it will be and therefore the more effect it will have on body roll. It is also very important to get the front – rear ARB balance correct. As with the rest of the cars suspension, tuning the ARB balance is an important factor to “perfecting” the cars chassis setup. Although the term “perfect” will vary from owner to owner and will very much be down to each individuals personal preference. Just as with the suspension dampening, the stiffer you make each end of the car will have different effects to the handling. A stiffer rear ARB will increase over steer whilst a stiffer front arb will increase understeer. So having “too much” ARB can actually result in less grip overall but having too little can result in excess body roll which will cause the wheels to lean onto the outside of the tyre and loose grip.
We have put this into a chart below to make it a little more simple to understand.
| Anti roll bar size: | Effect: |
| Larger front ARB | More Understeer. |
| Smaller front ARB | More Oversteer. |
| Larger rear ARB | More Oversteer. |
| Smaller rear ARB | More Understeer. |
What are my upgrade options?
Front upgrades
For the front of the car we recommend either using the stock 19mm under driveshaft ARB found on the TT, Cupra R and S3 or the stock 21mm under shaft ARB found on the R32. You can also remove the front anti roll bar altogether. Doing this will increase initial turn in grip but at the same time loose high speed stability. If removing the front ARB YOU MUST ensure that your spring rates are high enough to make up for the lack of ARB otherwise you will end up with a lot more body roll.
Rear upgrades FWD
There are multiple options available for this platform but our favourite is the 28mm bar made by Neuspeed. This bar is a great combination with the 19mm undershaft front ARB and creates a very well balanced car. It helps eliminate a lot of the understeer the stock car suffers from and, depending on which of the 3 hardness settings you have it on, can give some tail happy moments whilst letting off the throttle mid corner! Neuspeed also made a hollow 32mm RARB, this bar had the same properties as a 28mm bar but is a lot lighter. Sadly Neuspeed discontinued this bar many years ago and they are now are incredibly rare.
There are also other bars available such as the adjustable 24mm from whiteline, and a non adjustable 25mm bar supplied by Eibach. These bars will still make a HUGE difference compared to stock.
Rear Upgrades AWD
There are 3 different stock rear AWD bars available. The Audi tt bar is 14mm the golf 4motion bar is 16mm and the golf r32 bar is 19mm. A very common modification on the AWD cars is to do the “drill mod” where you drill the bar on the flat mounting point closer to the leverage point (towards the front of the car) to decrease the lever moment and effectively make the bar harder to bend.
Click here to see a how to guide of doing the drill mod.
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