The Birds' B-Series Sport Suspension Kit for BMW E82 1 Series Coupe, E87 1 Series Hatch, E88 1 Series Convertible, E90 3 Series Sedan and E92 3 Series Coupe models (including 130i, 135i and 335i) consist of specially valved Bilstein shock absorbers and bespoke Eibach springs designed by Birds to offer the ultimate improvement in BMW ride quality and handling on the Australia's diverse roads.

This kit is exclusive to Birds and distributed in Australia by SouthernBM, and the components are not available directly from the manufacturers.

Not for E82 1 Series M (1M), E90 M3 Sedan, E91 3 Series Touring, E92 M3 Coupe or E93 3 Series & M3 Convertible.

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Modifying a car suspension system can be likened to walking a tightrope. Enthusiastic drivers will want the ride to be firm, whilst still offering reasonable comfort. The chassis must perform with all of the standard cars’ positive attributes, removing the negative ones, whilst offering a more direct handling stance and improving all of the dynamic criteria.

The first tool in the suspension tuners’ armoury is the road springs. They dictate the primary stiffness of the suspension, and control the ride height of the car at front and rear axles. They also have a significant impact on the roll stiffness and aerodynamic stability as secondary factors. It is clear therefore that this starting point will be critical in its influence over every chassis tuning component. The problem here is that most tuners have a hugely mistaken belief that a sporty suspension must be inherently stiff, moreover it must also always be stiffer than standard.

When Birds set out to address ride quality problems, they took characteristic data from some of the industry's foremost experts, and compared professional road testers opinions of various vehicles. They determined that the characteristics required were those of the finest handling cars on the planet. There could be no doubt that if they could achieve a ride quality and handling balance of the E30 M3, their job would be done. Birds did not restrict themselves in the search to only the BMW marque, also identifying Lotus and Jaguar as particularly competent exponents of the “Art Of Ride And Handling”.

Birds tested the rates of standard springs, and renowned tuner's products too. Testing of the E87 chassis ultimately dictated the final prototype spec. With the first prototype set on the car, it was immediately obvious that the balance of the car had become more neutral, had vastly reduced the tendency of the car to hop across the peaks of bumps, loosing traction at the same time. More importantly, the ride quality had improved to a massive degree. We were definitely on to something...

After consultation with suspension guru Rhoddy Harvey-Bailey, Birds decided to restrict their search for the correct shock absorber components to Bilstein as their gas assisted shock absorbers can be easily tuned to achieve genuine damper curves. That is to say you can have different damper rates for slow and high speed damping. Thus it is possible to achieve good ride quality characteristics alongside superb handling capabilities at high speeds and loads.

Many shock absorber manufacturers publish damping curves, but in truth cannot really produce anything like the reverse gradients required for our project.

So, armed with the test car on the prototype springs, Birds set about the task of drawing damper curves. Once again, Birds road and dyno tested various different damper sets, found the versions that were closest to our ideal set-up, and produced drawings of their ideal curves using existing curves as a basis.

Bilstein quickly re-valved an existing damper set to the new spec and the results were a revelation! In the “before” settings, this amazingly quick car would communicate “back off”, causing the driver to hold back on the power when driving through and out of curves. After installing the complete prototype set, the car encourages use of the power much earlier, and without fear of the consequences of overambitious throttle application. Indeed the immediate impression on a "B road circuit" was that exit speeds were now so much higher - approaching to previous braking points seems the car was at least 20mph faster! You can feel the tyre smearing itself into the tarmac, the gentle build up of roll oversteer, but without the feeling that the car may suddenly loose grip on a bump, and pitch you through a hedge.

No way! Firstly, there is no means of adjusting the spring stiffness. Secondly, there can only be one correct standard damper rate for any given spring. Thirdly, anyone capable of correctly specifying spring and damper rates correctly is usually an industry professional. Leave this task to even the most experienced tuner, and what you are being offered is a hundred ways to get the set-up wrong.

Even professional race teams tend to have only two settings. One for the wet, and one for the dry.

There are three things that immediately bring the 1 and 3 series chassis up to scratch. Despite the revelations achieved by the B- Series suspension, Birds views have not changed in that respect. So to enjoy this car in it’s ultimate configuration, you will need to consider the Quaife differential, conventional (non-Runflat) tyres, and for the track the B-Series anti-roll bar set. We can recommend the perfect combination of equipment for your specific needs.

However, drivers will still benefit from the B Sport Suspension kit on an otherwise standard car. The ride quality improvement over the M-Sport suspension is massive, as is the handling balance and accessibility of performance.