Damper testing and matching

Damping adjustment allows you to fine tune coilovers for your car to suit your needs and the cars intended use. Adjustment should always be made in axle pairs, so both fronts must be tuned the same and both rears must be tuned the same.

Decreasing front damping will speed up the weight transfer as you apply the cars brakes thus increasing front traction. You want some degree of weight transfer to occur to load up the front tyres to maximize braking ability and to help the front end hook up for corner entry. The front loading helps prevent under steer.

Such subtle tweaking of the damping rates can make a big difference to the way the car handles. Coilovers and after market damper manufacturers run quality control system that can lead to a large variation in damper to damper performance. This means that you can have different damping rates at each corner of your car even when the dampers are dialed in to the same setting via their adjuster. Because damping settings are so crucial to a vehicles handling, this can lead to a handling imbalance where the car will pull slightly under braking and its turn in and mid corner handling characteristics can differ from left to right hand corners.

It’s because the damping rates are so crucial that BC Racing check each and every damper they produce on an in house damper dyno. The compression and rebound damping rates are recorded and the coilover kits are only put together using matched dampers. Through this in house individual checking BC Racing can be confident that the kits are produced with matching dampers. BC Racing coilovers run to a tolerance level 3 times more accurate than general original equipment manufacturers so the difference in damping rate between BC Racing coilover units is a third of that aimed for by most original equipment manufacturers.

BC Racing Coilovers - Straight replacement for original equipment

The BC Racing coilovers are a direct replacement for the original equipment. Unlike other brands of coilovers, the BC Racing range do not require brackets fabricating, cable ties or jubilee clips to install. The bottom mounts of the coilovers come with all brackets to take the original ABS sensor leads, brake lines, anti roll bar drop links, etc. Just take off your original equipment suspension and install the BC Racing suspension. A straightforward and simple install.

The BR series coilovers use a large 44mm diameter piston in a 53mm diameter damper body to maximize oil capacity.

As the damper unit operates the oil contained within heats up. The viscosity of oil changes as its temperature varies which can lead to changes in the damping characteristic of the unit.

BC Racing only uses very high quality oil with their coilovers but go that extra mile to maximize performance and build their BR range with a large 53mm diameter damper body. This increases the capacity of the unit which increases the volume of oil contained which in turn reduces the peak temperature and so significantly improves damper performance.

Corner weight adjustment:

The lower spring platforms of the BC Racing coilovers are adjustable. This allows the car to be set up for corner weighting to achieve perfect balance and ensures that maximum tyre efficiency is achieved.

The car needs to be placing equal weight on each tyre on an axle so both front tyres need to be taking equal loading as do both rears. This makes sure that both tyres are doing their equal share of work when cornering which increases overall grip, maximizes corner speed and reduces lap times.

Optional assister springs can be purchased to allow wheel droop to be dialed into the unit to suit specific needs.

Ride height adjustment

Ride height is determined by the position of the coilover bottom mount. The mount can be wound up and down the damper body to give a full range of adjustment from near standard ride height to so low it wouldn’t be drivable on the road.

Because ride height is determined by an adjustable bottom mount rather than spring platform you retain full damper travel regardless of the ride height run.

Damping adjustment:

BR coilovers feature 30 way damping adjustment that combines both rebound and compression in one adjuster for simplicity and ease of use. This adjustable facility allows you to fine tune the vehicle to meet the relevant conditions.

By tweaking front and rear damping you can adjust the way the car handles. Increasing damping force on the rear relative to the front, for example, will start moving the vehicle into a more oversteer orientated stance.

If you want to go drag racing in a rear wheel drive car then you want the back of the car to squat off the line to maximize weight transfer to the rear and therefore onto the rear tyres. This maximizes traction and helps prevent wheel spin. To achieve this you would soften the rear dampers to allow faster compression. If you had the rear dampers set to hard, as you might run the car on a race track, then the car would be less inclined to squat so traction would be reduced.

Conversely, if you want to go drifting and are finding it hard to break traction and are having problems with understeer then making the rear dampers harder will help reduce traction whilst making the front dampers softer will give greater front traction. This will make the rear of the car looser whilst minimizing understeer thus altering the vehicles handling characteristics more towards drift than drag, road or track.

Corrosion protection:

The damper units are black chromed steel to give superb durability even through the darkest of European winters. The aluminium components (top mounts, locking collars etc) are anodized and the steel lower mounts go through an electrophoretic disposition process followed by powder coating. A random selection of steel components (brackets, dampers, screws etc) are put through a salt spray test once a month to check the quality of the protective processes and that anti corrosive properties are kept at the highest possible standard.

High quality oil:

BC Racing dampers use a sophisticated shim stack design and high quality oil to consistently control the compression and rebound speed of the damper rod even under the most extreme conditions.

As the vehicles travels over rough ground the compression and rebound motion of the damper rod heats the oil. Poor quality dampers use cheap oil whose characteristics alter with varying temperatures. It’s vital that high quality oil is used that can maintain consistent viscosity under a wide temperature operating range. Once the oil start to degrade, its properties change leading to damping changes leading to changes in the vehicles handling characteristics.

BC Racing ensures that only high quality oil is used so that damping rates are maintained not only for the moment in hand (i.e. whilst out for a back road blast on or track) but that long term longevity is maximized with oil that doesn’t degrade quickly over time thus extending the dampers operating life significantly.

Nitrogen pressurized dampers:

When you work a damper hard on track or on high speed bumpy roads you can cause the oil to aerate and cavitations can occur. This cause foaming which effectively reduces the oils viscosity and so reduces the units damping effect. High quality oil goes a long way to help reduce this problem but BC Racing go one step further and pressurize the dampers with nitrogen. The nitrogen exerts a pressure on a floating piston which in turn exerts a permanent pressure on the oil dramatically reducing aeration and so improving the consistency and quality of the damping. The pressurized nitrogen also adds an additional element of effective spring rate to the damper unit.

Bearing mounted upper spring platform:

Because the spring twists as it compresses it is very important to minimize stiction between the spring and its seats. If this tension is not relieved then spring binding can occur leading to the spring rate effectively altering slightly as the spring compresses and extends. The tension generated can lead to rapid deterioration of the spring pearches and in extreme cases can cause the spring platform and locking collars to loosen. This can lead to the platform and locking collars ‘walking’ down the damper resulting in un even ride height and danger of the spring dislocating under full damper extension.

The friction between spring and seats also has an effect on steering effort as the springs are physically turned with the wheels. This introduces additional unnecessary friction into the steering system which has a knock on detrimental effect on the vehicles handling characteristics.

The bearing mounted upper spring platform is one of BC Racings innovative designs. By vastly reducing stiction between the spring and its seats the BC Racing units avoid the above problems thus improving the efficiency of the steering system and allowing the spring and damper to work as designed.