ello and welcome to the fi rst of a new series of product tests. It is all well and good writing about
what is new and shiny on the scene, but how do you know how well it works, how long it will last or whether it is good value for money? We are hoping to answer these questions and more, putting a whole string of components, from carbs to steering wheels, through their paces. To achieve this we are going to use a number of methods including track testing and dyno sessions that will allow us to give you the best information possible when choosing new kit for your Dub.
First up is a component that can truly make or break a car: dampers. Get them wrong and you can be in for loose fi llings and scary handling; get them right and you should enjoy a smooth-riding car with sweet handling. There is a huge range of dampers available on the market, from completely stock units through to high-spec racing shocks with multiple adjustment options and a price to match. We picked four of the most commonly available units, addressing the whole price spectrum, and put them through their paces at the Castle Combe circuit in Wiltshire. This is a circuit that has it all – fast, sweeping corners and slow technical chicanes, with a nice spattering of kerbs, bumps and surface changes.
What dampers do The primary role of dampers is to control the vertical movement of your wheels, both up and down. If
Team work was the name of the game: Removing four shocks and fi tting four different ones in 20 minutes, while contending with hot brakes is no mean feat
you just left a car to ride on springs alone, it would bounce around all over the place, with the result being that the occupants would have an uncomfortable journey, and more dangerously the wheels would rarely be in contact with the ground. It is this second point that makes dampers so important to the handling of a car. A great racing driver once observed “the only things between you and St Peter are four
consisted of two discs of friction material, held together by plates, and to increase the damping effect you simply tightened the plates together. By the 1950s
“Do you know how well it will work, or how long it’ll last?”
little patches or rubber”, and it is the dampers’ job to ensure that those four black squares are doing their job properly, because if they are not on the tarmac they aren’t producing any grip.
The earliest dampers simply
Oil-fi lled dampers: Oil-fi lled dampers are essentially an oil pump. A piston moves in a bath of oil which provides the resistance, or damping to the suspension movement.
Gas-pressurised: In a gas- pressurised shock the area not taken up by oil is fi lled with pressurised gas. This prevents cavitation in the oil, which is the formation of small gas bubbles in the oil when the damper is worked hard.
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most cars had adopted modern hydraulic dampers, however early Split Window Beetles came equipped with friction dampers. Nearly all dampers are now telescopic units that use oil as the damping medium, including all
of those on test. These rely on oil being squeezed through a series of small holes between two chambers, with the size of hole and the oil’s viscosity dictating the damping rate. Gas-pressurised units use a compressed gas to provide additional stiffness to the shock, with the gas pressure acting against the compression force of the suspension and then helping the shock return to its uncompressed length. Gas-pressurised units are generally stiffer than oil-only ones, with top of the range dampers having adjustable pressure to alter the damping characteristics and even remote gas reservoirs (this allows the gas to remain more stable as it is less
Upper mount
Piston rod Oil
Reserve cylinder Pressure tube Base valve
Lower mount
Extension cycle
Compression cycle
All of the dampers on this test (except stock) are available in a number of different lengths to suit varying ride heights. It is therefore vital to measure your suspension height before ordering new dampers, to ensure you get maximum performance. To do this:
= Remove the dampers already fi tted to the car = Rest the car back on its wheels = Measure the distance between the top and bottom shock mounts
= Specify a damper with extended and closed lengths at least 50mm either side of this fi gure
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